Update dependencies (#1610)

* Update dependencies

* Update module to go 1.17

vendor/github.com/mattermost/mattermost-server/v5/shared/filestore/filesstore.go

@@ -0,0 +1,83 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package filestore
+
+import (
+	"io"
+	"time"
+
+	"github.com/pkg/errors"
+)
+
+const (
+	driverS3    = "amazons3"
+	driverLocal = "local"
+)
+
+type ReadCloseSeeker interface {
+	io.ReadCloser
+	io.Seeker
+}
+
+type FileBackend interface {
+	TestConnection() error
+
+	Reader(path string) (ReadCloseSeeker, error)
+	ReadFile(path string) ([]byte, error)
+	FileExists(path string) (bool, error)
+	FileSize(path string) (int64, error)
+	CopyFile(oldPath, newPath string) error
+	MoveFile(oldPath, newPath string) error
+	WriteFile(fr io.Reader, path string) (int64, error)
+	AppendFile(fr io.Reader, path string) (int64, error)
+	RemoveFile(path string) error
+	FileModTime(path string) (time.Time, error)
+
+	ListDirectory(path string) ([]string, error)
+	RemoveDirectory(path string) error
+}
+
+type FileBackendSettings struct {
+	DriverName              string
+	Directory               string
+	AmazonS3AccessKeyId     string
+	AmazonS3SecretAccessKey string
+	AmazonS3Bucket          string
+	AmazonS3PathPrefix      string
+	AmazonS3Region          string
+	AmazonS3Endpoint        string
+	AmazonS3SSL             bool
+	AmazonS3SignV2          bool
+	AmazonS3SSE             bool
+	AmazonS3Trace           bool
+}
+
+func (settings *FileBackendSettings) CheckMandatoryS3Fields() error {
+	if settings.AmazonS3Bucket == "" {
+		return errors.New("missing s3 bucket settings")
+	}
+
+	// if S3 endpoint is not set call the set defaults to set that
+	if settings.AmazonS3Endpoint == "" {
+		settings.AmazonS3Endpoint = "s3.amazonaws.com"
+	}
+
+	return nil
+}
+
+func NewFileBackend(settings FileBackendSettings) (FileBackend, error) {
+	switch settings.DriverName {
+	case driverS3:
+		backend, err := NewS3FileBackend(settings)
+		if err != nil {
+			return nil, errors.Wrap(err, "unable to connect to the s3 backend")
+		}
+		return backend, nil
+	case driverLocal:
+		return &LocalFileBackend{
+			directory: settings.Directory,
+		}, nil
+	}
+	return nil, errors.New("no valid filestorage driver found")
+}

vendor/github.com/mattermost/mattermost-server/v5/shared/filestore/localstore.go

@@ -0,0 +1,211 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package filestore
+
+import (
+	"bytes"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/pkg/errors"
+
+	"github.com/mattermost/mattermost-server/v5/shared/mlog"
+)
+
+const (
+	TestFilePath = "/testfile"
+)
+
+type LocalFileBackend struct {
+	directory string
+}
+
+// copyFile will copy a file from src path to dst path.
+// Overwrites any existing files at dst.
+// Permissions are copied from file at src to the new file at dst.
+func copyFile(src, dst string) (err error) {
+	in, err := os.Open(src)
+	if err != nil {
+		return
+	}
+	defer in.Close()
+
+	if err = os.MkdirAll(filepath.Dir(dst), os.ModePerm); err != nil {
+		return
+	}
+	out, err := os.Create(dst)
+	if err != nil {
+		return
+	}
+	defer func() {
+		if e := out.Close(); e != nil {
+			err = e
+		}
+	}()
+
+	_, err = io.Copy(out, in)
+	if err != nil {
+		return
+	}
+
+	err = out.Sync()
+	if err != nil {
+		return
+	}
+
+	stat, err := os.Stat(src)
+	if err != nil {
+		return
+	}
+	err = os.Chmod(dst, stat.Mode())
+	if err != nil {
+		return
+	}
+
+	return
+}
+
+func (b *LocalFileBackend) TestConnection() error {
+	f := bytes.NewReader([]byte("testingwrite"))
+	if _, err := writeFileLocally(f, filepath.Join(b.directory, TestFilePath)); err != nil {
+		return errors.Wrap(err, "unable to write to the local filesystem storage")
+	}
+	os.Remove(filepath.Join(b.directory, TestFilePath))
+	mlog.Debug("Able to write files to local storage.")
+	return nil
+}
+
+func (b *LocalFileBackend) Reader(path string) (ReadCloseSeeker, error) {
+	f, err := os.Open(filepath.Join(b.directory, path))
+	if err != nil {
+		return nil, errors.Wrapf(err, "unable to open file %s", path)
+	}
+	return f, nil
+}
+
+func (b *LocalFileBackend) ReadFile(path string) ([]byte, error) {
+	f, err := ioutil.ReadFile(filepath.Join(b.directory, path))
+	if err != nil {
+		return nil, errors.Wrapf(err, "unable to read file %s", path)
+	}
+	return f, nil
+}
+
+func (b *LocalFileBackend) FileExists(path string) (bool, error) {
+	_, err := os.Stat(filepath.Join(b.directory, path))
+
+	if os.IsNotExist(err) {
+		return false, nil
+	}
+
+	if err != nil {
+		return false, errors.Wrapf(err, "unable to know if file %s exists", path)
+	}
+	return true, nil
+}
+
+func (b *LocalFileBackend) FileSize(path string) (int64, error) {
+	info, err := os.Stat(filepath.Join(b.directory, path))
+	if err != nil {
+		return 0, errors.Wrapf(err, "unable to get file size for %s", path)
+	}
+	return info.Size(), nil
+}
+
+func (b *LocalFileBackend) FileModTime(path string) (time.Time, error) {
+	info, err := os.Stat(filepath.Join(b.directory, path))
+	if err != nil {
+		return time.Time{}, errors.Wrapf(err, "unable to get modification time for file %s", path)
+	}
+	return info.ModTime(), nil
+}
+
+func (b *LocalFileBackend) CopyFile(oldPath, newPath string) error {
+	if err := copyFile(filepath.Join(b.directory, oldPath), filepath.Join(b.directory, newPath)); err != nil {
+		return errors.Wrapf(err, "unable to copy file from %s to %s", oldPath, newPath)
+	}
+	return nil
+}
+
+func (b *LocalFileBackend) MoveFile(oldPath, newPath string) error {
+	if err := os.MkdirAll(filepath.Dir(filepath.Join(b.directory, newPath)), 0750); err != nil {
+		return errors.Wrapf(err, "unable to create the new destination directory %s", filepath.Dir(newPath))
+	}
+
+	if err := os.Rename(filepath.Join(b.directory, oldPath), filepath.Join(b.directory, newPath)); err != nil {
+		return errors.Wrapf(err, "unable to move the file to %s to the destination directory", newPath)
+	}
+
+	return nil
+}
+
+func (b *LocalFileBackend) WriteFile(fr io.Reader, path string) (int64, error) {
+	return writeFileLocally(fr, filepath.Join(b.directory, path))
+}
+
+func writeFileLocally(fr io.Reader, path string) (int64, error) {
+	if err := os.MkdirAll(filepath.Dir(path), 0750); err != nil {
+		directory, _ := filepath.Abs(filepath.Dir(path))
+		return 0, errors.Wrapf(err, "unable to create the directory %s for the file %s", directory, path)
+	}
+	fw, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
+	if err != nil {
+		return 0, errors.Wrapf(err, "unable to open the file %s to write the data", path)
+	}
+	defer fw.Close()
+	written, err := io.Copy(fw, fr)
+	if err != nil {
+		return written, errors.Wrapf(err, "unable write the data in the file %s", path)
+	}
+	return written, nil
+}
+
+func (b *LocalFileBackend) AppendFile(fr io.Reader, path string) (int64, error) {
+	fp := filepath.Join(b.directory, path)
+	if _, err := os.Stat(fp); err != nil {
+		return 0, errors.Wrapf(err, "unable to find the file %s to append the data", path)
+	}
+	fw, err := os.OpenFile(fp, os.O_WRONLY|os.O_APPEND, 0600)
+	if err != nil {
+		return 0, errors.Wrapf(err, "unable to open the file %s to append the data", path)
+	}
+	defer fw.Close()
+	written, err := io.Copy(fw, fr)
+	if err != nil {
+		return written, errors.Wrapf(err, "unable append the data in the file %s", path)
+	}
+	return written, nil
+}
+
+func (b *LocalFileBackend) RemoveFile(path string) error {
+	if err := os.Remove(filepath.Join(b.directory, path)); err != nil {
+		return errors.Wrapf(err, "unable to remove the file %s", path)
+	}
+	return nil
+}
+
+func (b *LocalFileBackend) ListDirectory(path string) ([]string, error) {
+	var paths []string
+	fileInfos, err := ioutil.ReadDir(filepath.Join(b.directory, path))
+	if err != nil {
+		if os.IsNotExist(err) {
+			return paths, nil
+		}
+		return nil, errors.Wrapf(err, "unable to list the directory %s", path)
+	}
+	for _, fileInfo := range fileInfos {
+		paths = append(paths, filepath.Join(path, fileInfo.Name()))
+	}
+	return paths, nil
+}
+
+func (b *LocalFileBackend) RemoveDirectory(path string) error {
+	if err := os.RemoveAll(filepath.Join(b.directory, path)); err != nil {
+		return errors.Wrapf(err, "unable to remove the directory %s", path)
+	}
+	return nil
+}

vendor/github.com/mattermost/mattermost-server/v5/shared/filestore/s3_overrides.go

@@ -0,0 +1,56 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package filestore
+
+import (
+	"context"
+	"net/http"
+
+	"github.com/minio/minio-go/v7/pkg/credentials"
+)
+
+// customTransport is used to point the request to a different server.
+// This is helpful in situations where a different service is handling AWS S3 requests
+// from multiple Mattermost applications, and the Mattermost service itself does not
+// have any S3 credentials.
+type customTransport struct {
+	base   http.RoundTripper
+	host   string
+	scheme string
+	client http.Client
+}
+
+// RoundTrip implements the http.Roundtripper interface.
+func (t *customTransport) RoundTrip(req *http.Request) (*http.Response, error) {
+	// Rountrippers should not modify the original request.
+	newReq := req.Clone(context.Background())
+	*newReq.URL = *req.URL
+	req.URL.Scheme = t.scheme
+	req.URL.Host = t.host
+	return t.client.Do(req)
+}
+
+// customProvider is a dummy credentials provider for the minio client to work
+// without actually providing credentials. This is needed with a custom transport
+// in cases where the minio client does not actually have credentials with itself,
+// rather needs responses from another entity.
+//
+// It satisfies the credentials.Provider interface.
+type customProvider struct {
+	isSignV2 bool
+}
+
+// Retrieve just returns empty credentials.
+func (cp customProvider) Retrieve() (credentials.Value, error) {
+	sign := credentials.SignatureV4
+	if cp.isSignV2 {
+		sign = credentials.SignatureV2
+	}
+	return credentials.Value{
+		SignerType: sign,
+	}, nil
+}
+
+// IsExpired always returns false.
+func (cp customProvider) IsExpired() bool { return false }

vendor/github.com/mattermost/mattermost-server/v5/shared/filestore/s3store.go

@@ -0,0 +1,442 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package filestore
+
+import (
+	"context"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+
+	s3 "github.com/minio/minio-go/v7"
+	"github.com/minio/minio-go/v7/pkg/credentials"
+	"github.com/minio/minio-go/v7/pkg/encrypt"
+	"github.com/pkg/errors"
+
+	"github.com/mattermost/mattermost-server/v5/shared/mlog"
+)
+
+// S3FileBackend contains all necessary information to communicate with
+// an AWS S3 compatible API backend.
+type S3FileBackend struct {
+	endpoint   string
+	accessKey  string
+	secretKey  string
+	secure     bool
+	signV2     bool
+	region     string
+	bucket     string
+	pathPrefix string
+	encrypt    bool
+	trace      bool
+	client     *s3.Client
+}
+
+type S3FileBackendAuthError struct {
+	DetailedError string
+}
+
+// S3FileBackendNoBucketError is returned when testing a connection and no S3 bucket is found
+type S3FileBackendNoBucketError struct{}
+
+const (
+	// This is not exported by minio. See: https://github.com/minio/minio-go/issues/1339
+	bucketNotFound = "NoSuchBucket"
+)
+
+var (
+	imageExtensions = map[string]bool{".jpg": true, ".jpeg": true, ".gif": true, ".bmp": true, ".png": true, ".tiff": true, "tif": true}
+	imageMimeTypes  = map[string]string{".jpg": "image/jpeg", ".jpeg": "image/jpeg", ".gif": "image/gif", ".bmp": "image/bmp", ".png": "image/png", ".tiff": "image/tiff", ".tif": "image/tif"}
+)
+
+func isFileExtImage(ext string) bool {
+	ext = strings.ToLower(ext)
+	return imageExtensions[ext]
+}
+
+func getImageMimeType(ext string) string {
+	ext = strings.ToLower(ext)
+	if imageMimeTypes[ext] == "" {
+		return "image"
+	}
+	return imageMimeTypes[ext]
+}
+
+func (s *S3FileBackendAuthError) Error() string {
+	return s.DetailedError
+}
+
+func (s *S3FileBackendNoBucketError) Error() string {
+	return "no such bucket"
+}
+
+// NewS3FileBackend returns an instance of an S3FileBackend.
+func NewS3FileBackend(settings FileBackendSettings) (*S3FileBackend, error) {
+	backend := &S3FileBackend{
+		endpoint:   settings.AmazonS3Endpoint,
+		accessKey:  settings.AmazonS3AccessKeyId,
+		secretKey:  settings.AmazonS3SecretAccessKey,
+		secure:     settings.AmazonS3SSL,
+		signV2:     settings.AmazonS3SignV2,
+		region:     settings.AmazonS3Region,
+		bucket:     settings.AmazonS3Bucket,
+		pathPrefix: settings.AmazonS3PathPrefix,
+		encrypt:    settings.AmazonS3SSE,
+		trace:      settings.AmazonS3Trace,
+	}
+	cli, err := backend.s3New()
+	if err != nil {
+		return nil, err
+	}
+	backend.client = cli
+	return backend, nil
+}
+
+// Similar to s3.New() but allows initialization of signature v2 or signature v4 client.
+// If signV2 input is false, function always returns signature v4.
+//
+// Additionally this function also takes a user defined region, if set
+// disables automatic region lookup.
+func (b *S3FileBackend) s3New() (*s3.Client, error) {
+	var creds *credentials.Credentials
+
+	isCloud := os.Getenv("MM_CLOUD_FILESTORE_BIFROST") != ""
+	if isCloud {
+		creds = credentials.New(customProvider{isSignV2: b.signV2})
+	} else if b.accessKey == "" && b.secretKey == "" {
+		creds = credentials.NewIAM("")
+	} else if b.signV2 {
+		creds = credentials.NewStatic(b.accessKey, b.secretKey, "", credentials.SignatureV2)
+	} else {
+		creds = credentials.NewStatic(b.accessKey, b.secretKey, "", credentials.SignatureV4)
+	}
+
+	opts := s3.Options{
+		Creds:  creds,
+		Secure: b.secure,
+		Region: b.region,
+	}
+
+	// If this is a cloud installation, we override the default transport.
+	if isCloud {
+		tr, err := s3.DefaultTransport(b.secure)
+		if err != nil {
+			return nil, err
+		}
+		scheme := "http"
+		if b.secure {
+			scheme = "https"
+		}
+		opts.Transport = &customTransport{
+			base:   tr,
+			host:   b.endpoint,
+			scheme: scheme,
+		}
+	}
+
+	s3Clnt, err := s3.New(b.endpoint, &opts)
+	if err != nil {
+		return nil, err
+	}
+
+	if b.trace {
+		s3Clnt.TraceOn(os.Stdout)
+	}
+
+	return s3Clnt, nil
+}
+
+func (b *S3FileBackend) TestConnection() error {
+	exists := true
+	var err error
+	// If a path prefix is present, we attempt to test the bucket by listing objects under the path
+	// and just checking the first response. This is because the BucketExists call is only at a bucket level
+	// and sometimes the user might only be allowed access to the specified path prefix.
+	if b.pathPrefix != "" {
+		obj := <-b.client.ListObjects(context.Background(), b.bucket, s3.ListObjectsOptions{Prefix: b.pathPrefix})
+		if obj.Err != nil {
+			typedErr := s3.ToErrorResponse(obj.Err)
+			if typedErr.Code != bucketNotFound {
+				return &S3FileBackendAuthError{DetailedError: "unable to list objects in the S3 bucket"}
+			}
+			exists = false
+		}
+	} else {
+		exists, err = b.client.BucketExists(context.Background(), b.bucket)
+		if err != nil {
+			return &S3FileBackendAuthError{DetailedError: "unable to check if the S3 bucket exists"}
+		}
+	}
+
+	if !exists {
+		return &S3FileBackendNoBucketError{}
+	}
+	mlog.Debug("Connection to S3 or minio is good. Bucket exists.")
+	return nil
+}
+
+func (b *S3FileBackend) MakeBucket() error {
+	err := b.client.MakeBucket(context.Background(), b.bucket, s3.MakeBucketOptions{Region: b.region})
+	if err != nil {
+		return errors.Wrap(err, "unable to create the s3 bucket")
+	}
+	return nil
+}
+
+// Caller must close the first return value
+func (b *S3FileBackend) Reader(path string) (ReadCloseSeeker, error) {
+	path = filepath.Join(b.pathPrefix, path)
+	minioObject, err := b.client.GetObject(context.Background(), b.bucket, path, s3.GetObjectOptions{})
+	if err != nil {
+		return nil, errors.Wrapf(err, "unable to open file %s", path)
+	}
+
+	return minioObject, nil
+}
+
+func (b *S3FileBackend) ReadFile(path string) ([]byte, error) {
+	path = filepath.Join(b.pathPrefix, path)
+	minioObject, err := b.client.GetObject(context.Background(), b.bucket, path, s3.GetObjectOptions{})
+	if err != nil {
+		return nil, errors.Wrapf(err, "unable to open file %s", path)
+	}
+
+	defer minioObject.Close()
+	f, err := ioutil.ReadAll(minioObject)
+	if err != nil {
+		return nil, errors.Wrapf(err, "unable to read file %s", path)
+	}
+	return f, nil
+}
+
+func (b *S3FileBackend) FileExists(path string) (bool, error) {
+	path = filepath.Join(b.pathPrefix, path)
+
+	_, err := b.client.StatObject(context.Background(), b.bucket, path, s3.StatObjectOptions{})
+	if err == nil {
+		return true, nil
+	}
+
+	var s3Err s3.ErrorResponse
+	if errors.As(err, &s3Err); s3Err.Code == "NoSuchKey" {
+		return false, nil
+	}
+
+	return false, errors.Wrapf(err, "unable to know if file %s exists", path)
+}
+
+func (b *S3FileBackend) FileSize(path string) (int64, error) {
+	path = filepath.Join(b.pathPrefix, path)
+
+	info, err := b.client.StatObject(context.Background(), b.bucket, path, s3.StatObjectOptions{})
+	if err != nil {
+		return 0, errors.Wrapf(err, "unable to get file size for %s", path)
+	}
+
+	return info.Size, nil
+}
+
+func (b *S3FileBackend) FileModTime(path string) (time.Time, error) {
+	path = filepath.Join(b.pathPrefix, path)
+
+	info, err := b.client.StatObject(context.Background(), b.bucket, path, s3.StatObjectOptions{})
+	if err != nil {
+		return time.Time{}, errors.Wrapf(err, "unable to get modification time for file %s", path)
+	}
+
+	return info.LastModified, nil
+}
+
+func (b *S3FileBackend) CopyFile(oldPath, newPath string) error {
+	oldPath = filepath.Join(b.pathPrefix, oldPath)
+	newPath = filepath.Join(b.pathPrefix, newPath)
+	srcOpts := s3.CopySrcOptions{
+		Bucket:     b.bucket,
+		Object:     oldPath,
+		Encryption: encrypt.NewSSE(),
+	}
+	dstOpts := s3.CopyDestOptions{
+		Bucket:     b.bucket,
+		Object:     newPath,
+		Encryption: encrypt.NewSSE(),
+	}
+	if _, err := b.client.CopyObject(context.Background(), dstOpts, srcOpts); err != nil {
+		return errors.Wrapf(err, "unable to copy file from %s to %s", oldPath, newPath)
+	}
+	return nil
+}
+
+func (b *S3FileBackend) MoveFile(oldPath, newPath string) error {
+	oldPath = filepath.Join(b.pathPrefix, oldPath)
+	newPath = filepath.Join(b.pathPrefix, newPath)
+	srcOpts := s3.CopySrcOptions{
+		Bucket:     b.bucket,
+		Object:     oldPath,
+		Encryption: encrypt.NewSSE(),
+	}
+	dstOpts := s3.CopyDestOptions{
+		Bucket:     b.bucket,
+		Object:     newPath,
+		Encryption: encrypt.NewSSE(),
+	}
+
+	if _, err := b.client.CopyObject(context.Background(), dstOpts, srcOpts); err != nil {
+		return errors.Wrapf(err, "unable to copy the file to %s to the new destionation", newPath)
+	}
+
+	if err := b.client.RemoveObject(context.Background(), b.bucket, oldPath, s3.RemoveObjectOptions{}); err != nil {
+		return errors.Wrapf(err, "unable to remove the file old file %s", oldPath)
+	}
+
+	return nil
+}
+
+func (b *S3FileBackend) WriteFile(fr io.Reader, path string) (int64, error) {
+	var contentType string
+	path = filepath.Join(b.pathPrefix, path)
+	if ext := filepath.Ext(path); isFileExtImage(ext) {
+		contentType = getImageMimeType(ext)
+	} else {
+		contentType = "binary/octet-stream"
+	}
+
+	options := s3PutOptions(b.encrypt, contentType)
+	info, err := b.client.PutObject(context.Background(), b.bucket, path, fr, -1, options)
+	if err != nil {
+		return info.Size, errors.Wrapf(err, "unable write the data in the file %s", path)
+	}
+
+	return info.Size, nil
+}
+
+func (b *S3FileBackend) AppendFile(fr io.Reader, path string) (int64, error) {
+	fp := filepath.Join(b.pathPrefix, path)
+	if _, err := b.client.StatObject(context.Background(), b.bucket, fp, s3.StatObjectOptions{}); err != nil {
+		return 0, errors.Wrapf(err, "unable to find the file %s to append the data", path)
+	}
+
+	var contentType string
+	if ext := filepath.Ext(fp); isFileExtImage(ext) {
+		contentType = getImageMimeType(ext)
+	} else {
+		contentType = "binary/octet-stream"
+	}
+
+	options := s3PutOptions(b.encrypt, contentType)
+	sse := options.ServerSideEncryption
+	partName := fp + ".part"
+	info, err := b.client.PutObject(context.Background(), b.bucket, partName, fr, -1, options)
+	defer b.client.RemoveObject(context.Background(), b.bucket, partName, s3.RemoveObjectOptions{})
+	if info.Size > 0 {
+		src1Opts := s3.CopySrcOptions{
+			Bucket: b.bucket,
+			Object: fp,
+		}
+		src2Opts := s3.CopySrcOptions{
+			Bucket: b.bucket,
+			Object: partName,
+		}
+		dstOpts := s3.CopyDestOptions{
+			Bucket:     b.bucket,
+			Object:     fp,
+			Encryption: sse,
+		}
+		_, err = b.client.ComposeObject(context.Background(), dstOpts, src1Opts, src2Opts)
+		if err != nil {
+			return 0, errors.Wrapf(err, "unable append the data in the file %s", path)
+		}
+		return info.Size, nil
+	}
+
+	return 0, errors.Wrapf(err, "unable append the data in the file %s", path)
+}
+
+func (b *S3FileBackend) RemoveFile(path string) error {
+	path = filepath.Join(b.pathPrefix, path)
+	if err := b.client.RemoveObject(context.Background(), b.bucket, path, s3.RemoveObjectOptions{}); err != nil {
+		return errors.Wrapf(err, "unable to remove the file %s", path)
+	}
+
+	return nil
+}
+
+func getPathsFromObjectInfos(in <-chan s3.ObjectInfo) <-chan s3.ObjectInfo {
+	out := make(chan s3.ObjectInfo, 1)
+
+	go func() {
+		defer close(out)
+
+		for {
+			info, done := <-in
+
+			if !done {
+				break
+			}
+
+			out <- info
+		}
+	}()
+
+	return out
+}
+
+func (b *S3FileBackend) ListDirectory(path string) ([]string, error) {
+	path = filepath.Join(b.pathPrefix, path)
+	if !strings.HasSuffix(path, "/") && path != "" {
+		// s3Clnt returns only the path itself when "/" is not present
+		// appending "/" to make it consistent across all filestores
+		path = path + "/"
+	}
+
+	opts := s3.ListObjectsOptions{
+		Prefix: path,
+	}
+	var paths []string
+	for object := range b.client.ListObjects(context.Background(), b.bucket, opts) {
+		if object.Err != nil {
+			return nil, errors.Wrapf(object.Err, "unable to list the directory %s", path)
+		}
+		// We strip the path prefix that gets applied,
+		// so that it remains transparent to the application.
+		object.Key = strings.TrimPrefix(object.Key, b.pathPrefix)
+		trimmed := strings.Trim(object.Key, "/")
+		if trimmed != "" {
+			paths = append(paths, trimmed)
+		}
+	}
+
+	return paths, nil
+}
+
+func (b *S3FileBackend) RemoveDirectory(path string) error {
+	opts := s3.ListObjectsOptions{
+		Prefix:    filepath.Join(b.pathPrefix, path),
+		Recursive: true,
+	}
+	list := b.client.ListObjects(context.Background(), b.bucket, opts)
+	objectsCh := b.client.RemoveObjects(context.Background(), b.bucket, getPathsFromObjectInfos(list), s3.RemoveObjectsOptions{})
+	for err := range objectsCh {
+		if err.Err != nil {
+			return errors.Wrapf(err.Err, "unable to remove the directory %s", path)
+		}
+	}
+
+	return nil
+}
+
+func s3PutOptions(encrypted bool, contentType string) s3.PutObjectOptions {
+	options := s3.PutObjectOptions{}
+	if encrypted {
+		options.ServerSideEncryption = encrypt.NewSSE()
+	}
+	options.ContentType = contentType
+	// We set the part size to the minimum allowed value of 5MBs
+	// to avoid an excessive allocation in minio.PutObject implementation.
+	options.PartSize = 1024 * 1024 * 5
+
+	return options
+}

vendor/github.com/mattermost/mattermost-server/v5/shared/i18n/i18n.go

@@ -0,0 +1,185 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package i18n
+
+import (
+	"fmt"
+	"html/template"
+	"io/ioutil"
+	"net/http"
+	"path/filepath"
+	"reflect"
+	"strings"
+
+	"github.com/mattermost/go-i18n/i18n"
+
+	"github.com/mattermost/mattermost-server/v5/shared/mlog"
+)
+
+const defaultLocale = "en"
+
+// TranslateFunc is the type of the translate functions
+type TranslateFunc func(translationID string, args ...interface{}) string
+
+// T is the translate function using the default server language as fallback language
+var T TranslateFunc
+
+// TDefault is the translate function using english as fallback language
+var TDefault TranslateFunc
+
+var locales map[string]string = make(map[string]string)
+var defaultServerLocale string
+var defaultClientLocale string
+
+// TranslationsPreInit loads translations from filesystem if they are not
+// loaded already and assigns english while loading server config
+func TranslationsPreInit(translationsDir string) error {
+	if T != nil {
+		return nil
+	}
+
+	// Set T even if we fail to load the translations. Lots of shutdown handling code will
+	// segfault trying to handle the error, and the untranslated IDs are strictly better.
+	T = tfuncWithFallback(defaultLocale)
+	TDefault = tfuncWithFallback(defaultLocale)
+
+	return initTranslationsWithDir(translationsDir)
+}
+
+// InitTranslations set the defaults configured in the server and initialize
+// the T function using the server default as fallback language
+func InitTranslations(serverLocale, clientLocale string) error {
+	defaultServerLocale = serverLocale
+	defaultClientLocale = clientLocale
+
+	var err error
+	T, err = getTranslationsBySystemLocale()
+	return err
+}
+
+func initTranslationsWithDir(dir string) error {
+	files, _ := ioutil.ReadDir(dir)
+	for _, f := range files {
+		if filepath.Ext(f.Name()) == ".json" {
+			filename := f.Name()
+			locales[strings.Split(filename, ".")[0]] = filepath.Join(dir, filename)
+
+			if err := i18n.LoadTranslationFile(filepath.Join(dir, filename)); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+func getTranslationsBySystemLocale() (TranslateFunc, error) {
+	locale := defaultServerLocale
+	if _, ok := locales[locale]; !ok {
+		mlog.Warn("Failed to load system translations for", mlog.String("locale", locale), mlog.String("attempting to fall back to default locale", defaultLocale))
+		locale = defaultLocale
+	}
+
+	if locales[locale] == "" {
+		return nil, fmt.Errorf("failed to load system translations for '%v'", defaultLocale)
+	}
+
+	translations := tfuncWithFallback(locale)
+	if translations == nil {
+		return nil, fmt.Errorf("failed to load system translations")
+	}
+
+	mlog.Info("Loaded system translations", mlog.String("for locale", locale), mlog.String("from locale", locales[locale]))
+	return translations, nil
+}
+
+// GetUserTranslations get the translation function for an specific locale
+func GetUserTranslations(locale string) TranslateFunc {
+	if _, ok := locales[locale]; !ok {
+		locale = defaultLocale
+	}
+
+	translations := tfuncWithFallback(locale)
+	return translations
+}
+
+// GetTranslationsAndLocaleFromRequest return the translation function and the
+// locale based on a request headers
+func GetTranslationsAndLocaleFromRequest(r *http.Request) (TranslateFunc, string) {
+	// This is for checking against locales like pt_BR or zn_CN
+	headerLocaleFull := strings.Split(r.Header.Get("Accept-Language"), ",")[0]
+	// This is for checking against locales like en, es
+	headerLocale := strings.Split(strings.Split(r.Header.Get("Accept-Language"), ",")[0], "-")[0]
+	defaultLocale := defaultClientLocale
+	if locales[headerLocaleFull] != "" {
+		translations := tfuncWithFallback(headerLocaleFull)
+		return translations, headerLocaleFull
+	} else if locales[headerLocale] != "" {
+		translations := tfuncWithFallback(headerLocale)
+		return translations, headerLocale
+	} else if locales[defaultLocale] != "" {
+		translations := tfuncWithFallback(defaultLocale)
+		return translations, headerLocale
+	}
+
+	translations := tfuncWithFallback(defaultLocale)
+	return translations, defaultLocale
+}
+
+// GetSupportedLocales return a map of locale code and the file path with the
+// translations
+func GetSupportedLocales() map[string]string {
+	return locales
+}
+
+func tfuncWithFallback(pref string) TranslateFunc {
+	t, _ := i18n.Tfunc(pref)
+	return func(translationID string, args ...interface{}) string {
+		if translated := t(translationID, args...); translated != translationID {
+			return translated
+		}
+
+		t, _ := i18n.Tfunc(defaultLocale)
+		return t(translationID, args...)
+	}
+}
+
+// TranslateAsHTML translates the translationID provided and return a
+// template.HTML object
+func TranslateAsHTML(t TranslateFunc, translationID string, args map[string]interface{}) template.HTML {
+	message := t(translationID, escapeForHTML(args))
+	message = strings.Replace(message, "[[", "<strong>", -1)
+	message = strings.Replace(message, "]]", "</strong>", -1)
+	return template.HTML(message)
+}
+
+func escapeForHTML(arg interface{}) interface{} {
+	switch typedArg := arg.(type) {
+	case string:
+		return template.HTMLEscapeString(typedArg)
+	case *string:
+		return template.HTMLEscapeString(*typedArg)
+	case map[string]interface{}:
+		safeArg := make(map[string]interface{}, len(typedArg))
+		for key, value := range typedArg {
+			safeArg[key] = escapeForHTML(value)
+		}
+		return safeArg
+	default:
+		mlog.Warn(
+			"Unable to escape value for HTML template",
+			mlog.Any("html_template", arg),
+			mlog.String("template_type", reflect.ValueOf(arg).Type().String()),
+		)
+		return ""
+	}
+}
+
+// IdentityTfunc returns a translation function that don't translate, only
+// returns the same id
+func IdentityTfunc() TranslateFunc {
+	return func(translationID string, args ...interface{}) string {
+		return translationID
+	}
+}

vendor/github.com/mattermost/mattermost-server/v5/shared/markdown/autolink.go

@@ -0,0 +1,255 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package markdown
+
+import (
+	"regexp"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+)
+
+// Based off of extensions/autolink.c from https://github.com/github/cmark
+
+var (
+	DefaultURLSchemes = []string{"http", "https", "ftp", "mailto", "tel"}
+	wwwAutoLinkRegex  = regexp.MustCompile(`^www\d{0,3}\.`)
+)
+
+// Given a string with a w at the given position, tries to parse and return a range containing a www link.
+// if one exists. If the text at the given position isn't a link, returns an empty string. Equivalent to
+// www_match from the reference code.
+func parseWWWAutolink(data string, position int) (Range, bool) {
+	// Check that this isn't part of another word
+	if position > 1 {
+		prevChar := data[position-1]
+
+		if !isWhitespaceByte(prevChar) && !isAllowedBeforeWWWLink(prevChar) {
+			return Range{}, false
+		}
+	}
+
+	// Check that this starts with www
+	if len(data)-position < 4 || !wwwAutoLinkRegex.MatchString(data[position:]) {
+		return Range{}, false
+	}
+
+	end := checkDomain(data[position:], false)
+	if end == 0 {
+		return Range{}, false
+	}
+
+	end += position
+
+	// Grab all text until the end of the string or the next whitespace character
+	for end < len(data) && !isWhitespaceByte(data[end]) {
+		end += 1
+	}
+
+	// Trim trailing punctuation
+	end = trimTrailingCharactersFromLink(data, position, end)
+	if position == end {
+		return Range{}, false
+	}
+
+	return Range{position, end}, true
+}
+
+func isAllowedBeforeWWWLink(c byte) bool {
+	switch c {
+	case '*', '_', '~', ')':
+		return true
+	}
+	return false
+}
+
+// Given a string with a : at the given position, tried to parse and return a range containing a URL scheme
+// if one exists. If the text around the given position isn't a link, returns an empty string. Equivalent to
+// url_match from the reference code.
+func parseURLAutolink(data string, position int) (Range, bool) {
+	// Check that a :// exists. This doesn't match the clients that treat the slashes as optional.
+	if len(data)-position < 4 || data[position+1] != '/' || data[position+2] != '/' {
+		return Range{}, false
+	}
+
+	start := position - 1
+	for start > 0 && isAlphanumericByte(data[start-1]) {
+		start -= 1
+	}
+
+	if start < 0 || position >= len(data) {
+		return Range{}, false
+	}
+
+	// Ensure that the URL scheme is allowed and that at least one character after the scheme is valid.
+	scheme := data[start:position]
+	if !isSchemeAllowed(scheme) || !isValidHostCharacter(data[position+3:]) {
+		return Range{}, false
+	}
+
+	end := checkDomain(data[position+3:], true)
+	if end == 0 {
+		return Range{}, false
+	}
+
+	end += position
+
+	// Grab all text until the end of the string or the next whitespace character
+	for end < len(data) && !isWhitespaceByte(data[end]) {
+		end += 1
+	}
+
+	// Trim trailing punctuation
+	end = trimTrailingCharactersFromLink(data, start, end)
+	if start == end {
+		return Range{}, false
+	}
+
+	return Range{start, end}, true
+}
+
+func isSchemeAllowed(scheme string) bool {
+	// Note that this doesn't support the custom URL schemes implemented by the client
+	for _, allowed := range DefaultURLSchemes {
+		if strings.EqualFold(allowed, scheme) {
+			return true
+		}
+	}
+
+	return false
+}
+
+// Given a string starting with a URL, returns the number of valid characters that make up the URL's domain.
+// Returns 0 if the string doesn't start with a domain name. allowShort determines whether or not the domain
+// needs to contain a period to be considered valid. Equivalent to check_domain from the reference code.
+func checkDomain(data string, allowShort bool) int {
+	foundUnderscore := false
+	foundPeriod := false
+
+	i := 1
+	for ; i < len(data)-1; i++ {
+		if data[i] == '_' {
+			foundUnderscore = true
+			break
+		} else if data[i] == '.' {
+			foundPeriod = true
+		} else if !isValidHostCharacter(data[i:]) && data[i] != '-' {
+			break
+		}
+	}
+
+	if foundUnderscore {
+		return 0
+	}
+
+	if allowShort {
+		// If allowShort is set, accept any string of valid domain characters
+		return i
+	}
+
+	// If allowShort isn't set, a valid domain just requires at least a single period. Note that this
+	// logic isn't entirely necessary because we already know the string starts with "www." when
+	// this is called from parseWWWAutolink
+	if foundPeriod {
+		return i
+	}
+	return 0
+}
+
+// Returns true if the provided link starts with a valid character for a domain name. Equivalent to
+// is_valid_hostchar from the reference code.
+func isValidHostCharacter(link string) bool {
+	c, _ := utf8.DecodeRuneInString(link)
+	if c == utf8.RuneError {
+		return false
+	}
+
+	return !unicode.IsSpace(c) && !unicode.IsPunct(c)
+}
+
+// Removes any trailing characters such as punctuation or stray brackets that shouldn't be part of the link.
+// Returns a new end position for the link. Equivalent to autolink_delim from the reference code.
+func trimTrailingCharactersFromLink(markdown string, start int, end int) int {
+	runes := []rune(markdown[start:end])
+	linkEnd := len(runes)
+
+	// Cut off the link before an open angle bracket if it contains one
+	for i, c := range runes {
+		if c == '<' {
+			linkEnd = i
+			break
+		}
+	}
+
+	for linkEnd > 0 {
+		c := runes[linkEnd-1]
+
+		if !canEndAutolink(c) {
+			// Trim trailing quotes, periods, etc
+			linkEnd = linkEnd - 1
+		} else if c == ';' {
+			// Trim a trailing HTML entity
+			newEnd := linkEnd - 2
+
+			for newEnd > 0 && ((runes[newEnd] >= 'a' && runes[newEnd] <= 'z') || (runes[newEnd] >= 'A' && runes[newEnd] <= 'Z')) {
+				newEnd -= 1
+			}
+
+			if newEnd < linkEnd-2 && runes[newEnd] == '&' {
+				linkEnd = newEnd
+			} else {
+				// This isn't actually an HTML entity, so just trim the semicolon
+				linkEnd = linkEnd - 1
+			}
+		} else if c == ')' {
+			// Only allow an autolink ending with a bracket if that bracket is part of a matching pair of brackets.
+			// If there are more closing brackets than opening ones, remove the extra bracket
+
+			numClosing := 0
+			numOpening := 0
+
+			// Examples (input text => output linked portion):
+			//
+			//  http://www.pokemon.com/Pikachu_(Electric)
+			//    => http://www.pokemon.com/Pikachu_(Electric)
+			//
+			//  http://www.pokemon.com/Pikachu_((Electric)
+			//    => http://www.pokemon.com/Pikachu_((Electric)
+			//
+			//  http://www.pokemon.com/Pikachu_(Electric))
+			//    => http://www.pokemon.com/Pikachu_(Electric)
+			//
+			//  http://www.pokemon.com/Pikachu_((Electric))
+			//    => http://www.pokemon.com/Pikachu_((Electric))
+
+			for i := 0; i < linkEnd; i++ {
+				if runes[i] == '(' {
+					numOpening += 1
+				} else if runes[i] == ')' {
+					numClosing += 1
+				}
+			}
+
+			if numClosing <= numOpening {
+				// There's fewer or equal closing brackets, so we've found the end of the link
+				break
+			}
+
+			linkEnd -= 1
+		} else {
+			// There's no special characters at the end of the link, so we're at the end
+			break
+		}
+	}
+
+	return start + len(string(runes[:linkEnd]))
+}
+
+func canEndAutolink(c rune) bool {
+	switch c {
+	case '?', '!', '.', ',', ':', '*', '_', '~', '\'', '"':
+		return false
+	}
+	return true
+}

vendor/github.com/mattermost/mattermost-server/v5/shared/markdown/block_quote.go

@@ -0,0 +1,62 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package markdown
+
+type BlockQuote struct {
+	blockBase
+	markdown string
+
+	Children []Block
+}
+
+func (b *BlockQuote) Continuation(indentation int, r Range) *continuation {
+	if indentation > 3 {
+		return nil
+	}
+	s := b.markdown[r.Position:r.End]
+	if s == "" || s[0] != '>' {
+		return nil
+	}
+	remaining := Range{r.Position + 1, r.End}
+	indentation, indentationBytes := countIndentation(b.markdown, remaining)
+	if indentation > 0 {
+		indentation--
+	}
+	return &continuation{
+		Indentation: indentation,
+		Remaining:   Range{remaining.Position + indentationBytes, remaining.End},
+	}
+}
+
+func (b *BlockQuote) AddChild(openBlocks []Block) []Block {
+	b.Children = append(b.Children, openBlocks[0])
+	return openBlocks
+}
+
+func blockQuoteStart(markdown string, indent int, r Range) []Block {
+	if indent > 3 {
+		return nil
+	}
+	s := markdown[r.Position:r.End]
+	if s == "" || s[0] != '>' {
+		return nil
+	}
+
+	block := &BlockQuote{
+		markdown: markdown,
+	}
+	r.Position++
+	if len(s) > 1 && s[1] == ' ' {
+		r.Position++
+	}
+
+	indent, bytes := countIndentation(markdown, r)
+
+	ret := []Block{block}
+	if descendants := blockStartOrParagraph(markdown, indent, Range{r.Position + bytes, r.End}, nil, nil); descendants != nil {
+		block.Children = append(block.Children, descendants[0])
+		ret = append(ret, descendants...)
+	}
+	return ret
+}

vendor/github.com/mattermost/mattermost-server/v5/shared/markdown/blocks.go

@@ -0,0 +1,154 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package markdown
+
+import (
+	"strings"
+)
+
+type continuation struct {
+	Indentation int
+	Remaining   Range
+}
+
+type Block interface {
+	Continuation(indentation int, r Range) *continuation
+	AddLine(indentation int, r Range) bool
+	Close()
+	AllowsBlockStarts() bool
+	HasTrailingBlankLine() bool
+}
+
+type blockBase struct{}
+
+func (*blockBase) AddLine(indentation int, r Range) bool { return false }
+func (*blockBase) Close()                                {}
+func (*blockBase) AllowsBlockStarts() bool               { return true }
+func (*blockBase) HasTrailingBlankLine() bool            { return false }
+
+type ContainerBlock interface {
+	Block
+	AddChild(openBlocks []Block) []Block
+}
+
+type Range struct {
+	Position int
+	End      int
+}
+
+func closeBlocks(blocks []Block, referenceDefinitions []*ReferenceDefinition) []*ReferenceDefinition {
+	for _, block := range blocks {
+		block.Close()
+		if p, ok := block.(*Paragraph); ok && len(p.ReferenceDefinitions) > 0 {
+			referenceDefinitions = append(referenceDefinitions, p.ReferenceDefinitions...)
+		}
+	}
+	return referenceDefinitions
+}
+
+func ParseBlocks(markdown string, lines []Line) (*Document, []*ReferenceDefinition) {
+	document := &Document{}
+	var referenceDefinitions []*ReferenceDefinition
+
+	openBlocks := []Block{document}
+
+	for _, line := range lines {
+		r := line.Range
+		lastMatchIndex := 0
+
+		indentation, indentationBytes := countIndentation(markdown, r)
+		r = Range{r.Position + indentationBytes, r.End}
+
+		for i, block := range openBlocks {
+			if continuation := block.Continuation(indentation, r); continuation != nil {
+				indentation = continuation.Indentation
+				r = continuation.Remaining
+				additionalIndentation, additionalIndentationBytes := countIndentation(markdown, r)
+				r = Range{r.Position + additionalIndentationBytes, r.End}
+				indentation += additionalIndentation
+				lastMatchIndex = i
+			} else {
+				break
+			}
+		}
+
+		if openBlocks[lastMatchIndex].AllowsBlockStarts() {
+			if newBlocks := blockStart(markdown, indentation, r, openBlocks[:lastMatchIndex+1], openBlocks[lastMatchIndex+1:]); newBlocks != nil {
+				didAdd := false
+				for i := lastMatchIndex; i >= 0; i-- {
+					if container, ok := openBlocks[i].(ContainerBlock); ok {
+						if addedBlocks := container.AddChild(newBlocks); addedBlocks != nil {
+							referenceDefinitions = closeBlocks(openBlocks[i+1:], referenceDefinitions)
+							openBlocks = openBlocks[:i+1]
+							openBlocks = append(openBlocks, addedBlocks...)
+							didAdd = true
+							break
+						}
+					}
+				}
+				if didAdd {
+					continue
+				}
+			}
+		}
+
+		isBlank := strings.TrimSpace(markdown[r.Position:r.End]) == ""
+		if paragraph, ok := openBlocks[len(openBlocks)-1].(*Paragraph); ok && !isBlank {
+			paragraph.Text = append(paragraph.Text, r)
+			continue
+		}
+
+		referenceDefinitions = closeBlocks(openBlocks[lastMatchIndex+1:], referenceDefinitions)
+		openBlocks = openBlocks[:lastMatchIndex+1]
+
+		if openBlocks[lastMatchIndex].AddLine(indentation, r) {
+			continue
+		}
+
+		if paragraph := newParagraph(markdown, r); paragraph != nil {
+			for i := lastMatchIndex; i >= 0; i-- {
+				if container, ok := openBlocks[i].(ContainerBlock); ok {
+					if newBlocks := container.AddChild([]Block{paragraph}); newBlocks != nil {
+						referenceDefinitions = closeBlocks(openBlocks[i+1:], referenceDefinitions)
+						openBlocks = openBlocks[:i+1]
+						openBlocks = append(openBlocks, newBlocks...)
+						break
+					}
+				}
+			}
+		}
+	}
+
+	referenceDefinitions = closeBlocks(openBlocks, referenceDefinitions)
+
+	return document, referenceDefinitions
+}
+
+func blockStart(markdown string, indentation int, r Range, matchedBlocks, unmatchedBlocks []Block) []Block {
+	if r.Position >= r.End {
+		return nil
+	}
+
+	if start := blockQuoteStart(markdown, indentation, r); start != nil {
+		return start
+	} else if start := listStart(markdown, indentation, r, matchedBlocks, unmatchedBlocks); start != nil {
+		return start
+	} else if start := indentedCodeStart(markdown, indentation, r, matchedBlocks, unmatchedBlocks); start != nil {
+		return start
+	} else if start := fencedCodeStart(markdown, indentation, r); start != nil {
+		return start
+	}
+
+	return nil
+}
+
+func blockStartOrParagraph(markdown string, indentation int, r Range, matchedBlocks, unmatchedBlocks []Block) []Block {
+	if start := blockStart(markdown, indentation, r, matchedBlocks, unmatchedBlocks); start != nil {
+		return start
+	}
+	if paragraph := newParagraph(markdown, r); paragraph != nil {
+		return []Block{paragraph}
+	}
+	return nil
+}

vendor/github.com/mattermost/mattermost-server/v5/shared/markdown/document.go

@@ -0,0 +1,22 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package markdown
+
+type Document struct {
+	blockBase
+
+	Children []Block
+}
+
+func (b *Document) Continuation(indentation int, r Range) *continuation {
+	return &continuation{
+		Indentation: indentation,
+		Remaining:   r,
+	}
+}
+
+func (b *Document) AddChild(openBlocks []Block) []Block {
+	b.Children = append(b.Children, openBlocks[0])
+	return openBlocks
+}

vendor/github.com/mattermost/mattermost-server/v5/shared/markdown/fenced_code.go

@@ -0,0 +1,112 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package markdown
+
+import (
+	"strings"
+)
+
+type FencedCodeLine struct {
+	Indentation int
+	Range       Range
+}
+
+type FencedCode struct {
+	blockBase
+	markdown           string
+	didSeeClosingFence bool
+
+	Indentation  int
+	OpeningFence Range
+	RawInfo      Range
+	RawCode      []FencedCodeLine
+}
+
+func (b *FencedCode) Code() (result string) {
+	for _, code := range b.RawCode {
+		result += strings.Repeat(" ", code.Indentation) + b.markdown[code.Range.Position:code.Range.End]
+	}
+	return
+}
+
+func (b *FencedCode) Info() string {
+	return Unescape(b.markdown[b.RawInfo.Position:b.RawInfo.End])
+}
+
+func (b *FencedCode) Continuation(indentation int, r Range) *continuation {
+	if b.didSeeClosingFence {
+		return nil
+	}
+	return &continuation{
+		Indentation: indentation,
+		Remaining:   r,
+	}
+}
+
+func (b *FencedCode) AddLine(indentation int, r Range) bool {
+	s := b.markdown[r.Position:r.End]
+	if indentation <= 3 && strings.HasPrefix(s, b.markdown[b.OpeningFence.Position:b.OpeningFence.End]) {
+		suffix := strings.TrimSpace(s[b.OpeningFence.End-b.OpeningFence.Position:])
+		isClosingFence := true
+		for _, c := range suffix {
+			if c != rune(s[0]) {
+				isClosingFence = false
+				break
+			}
+		}
+		if isClosingFence {
+			b.didSeeClosingFence = true
+			return true
+		}
+	}
+
+	if indentation >= b.Indentation {
+		indentation -= b.Indentation
+	} else {
+		indentation = 0
+	}
+
+	b.RawCode = append(b.RawCode, FencedCodeLine{
+		Indentation: indentation,
+		Range:       r,
+	})
+	return true
+}
+
+func (b *FencedCode) AllowsBlockStarts() bool {
+	return false
+}
+
+func fencedCodeStart(markdown string, indentation int, r Range) []Block {
+	s := markdown[r.Position:r.End]
+
+	if !strings.HasPrefix(s, "```") && !strings.HasPrefix(s, "~~~") {
+		return nil
+	}
+
+	fenceCharacter := rune(s[0])
+	fenceLength := 3
+	for _, c := range s[3:] {
+		if c == fenceCharacter {
+			fenceLength++
+		} else {
+			break
+		}
+	}
+
+	for i := r.Position + fenceLength; i < r.End; i++ {
+		if markdown[i] == '`' {
+			return nil
+		}
+	}
+
+	return []Block{
+		&FencedCode{
+			markdown:     markdown,
+			Indentation:  indentation,
+			RawInfo:      trimRightSpace(markdown, Range{r.Position + fenceLength, r.End}),
+			OpeningFence: Range{r.Position, r.Position + fenceLength},
+		},
+	}
+}

vendor/github.com/mattermost/mattermost-server/v5/shared/markdown/html.go

@@ -0,0 +1,192 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package markdown
+
+import (
+	"fmt"
+	"strings"
+)
+
+var htmlEscaper = strings.NewReplacer(
+	`&`, "&",
+	`<`, "&lt;",
+	`>`, "&gt;",
+	`"`, "&quot;",
+)
+
+// RenderHTML produces HTML with the same behavior as the example renderer used in the CommonMark
+// reference materials except for one slight difference: for brevity, no unnecessary whitespace is
+// inserted between elements. The output is not defined by the CommonMark spec, and it exists
+// primarily as an aid in testing.
+func RenderHTML(markdown string) string {
+	return RenderBlockHTML(Parse(markdown))
+}
+
+func RenderBlockHTML(block Block, referenceDefinitions []*ReferenceDefinition) (result string) {
+	return renderBlockHTML(block, referenceDefinitions, false)
+}
+
+func renderBlockHTML(block Block, referenceDefinitions []*ReferenceDefinition, isTightList bool) (result string) {
+	switch v := block.(type) {
+	case *Document:
+		for _, block := range v.Children {
+			result += RenderBlockHTML(block, referenceDefinitions)
+		}
+	case *Paragraph:
+		if len(v.Text) == 0 {
+			return
+		}
+		if !isTightList {
+			result += "<p>"
+		}
+		for _, inline := range v.ParseInlines(referenceDefinitions) {
+			result += RenderInlineHTML(inline)
+		}
+		if !isTightList {
+			result += "</p>"
+		}
+	case *List:
+		if v.IsOrdered {
+			if v.OrderedStart != 1 {
+				result += fmt.Sprintf(`<ol start="%v">`, v.OrderedStart)
+			} else {
+				result += "<ol>"
+			}
+		} else {
+			result += "<ul>"
+		}
+		for _, block := range v.Children {
+			result += renderBlockHTML(block, referenceDefinitions, !v.IsLoose)
+		}
+		if v.IsOrdered {
+			result += "</ol>"
+		} else {
+			result += "</ul>"
+		}
+	case *ListItem:
+		result += "<li>"
+		for _, block := range v.Children {
+			result += renderBlockHTML(block, referenceDefinitions, isTightList)
+		}
+		result += "</li>"
+	case *BlockQuote:
+		result += "<blockquote>"
+		for _, block := range v.Children {
+			result += RenderBlockHTML(block, referenceDefinitions)
+		}
+		result += "</blockquote>"
+	case *FencedCode:
+		if info := v.Info(); info != "" {
+			language := strings.Fields(info)[0]
+			result += `<pre><code class="language-` + htmlEscaper.Replace(language) + `">`
+		} else {
+			result += "<pre><code>"
+		}
+		result += htmlEscaper.Replace(v.Code()) + "</code></pre>"
+	case *IndentedCode:
+		result += "<pre><code>" + htmlEscaper.Replace(v.Code()) + "</code></pre>"
+	default:
+		panic(fmt.Sprintf("missing case for type %T", v))
+	}
+	return
+}
+
+func escapeURL(url string) (result string) {
+	for i := 0; i < len(url); {
+		switch b := url[i]; b {
+		case ';', '/', '?', ':', '@', '&', '=', '+', '$', ',', '-', '_', '.', '!', '~', '*', '\'', '(', ')', '#':
+			result += string(b)
+			i++
+		default:
+			if b == '%' && i+2 < len(url) && isHexByte(url[i+1]) && isHexByte(url[i+2]) {
+				result += url[i : i+3]
+				i += 3
+			} else if (b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z') || (b >= '0' && b <= '9') {
+				result += string(b)
+				i++
+			} else {
+				result += fmt.Sprintf("%%%0X", b)
+				i++
+			}
+		}
+	}
+	return
+}
+
+func RenderInlineHTML(inline Inline) (result string) {
+	switch v := inline.(type) {
+	case *Text:
+		return htmlEscaper.Replace(v.Text)
+	case *HardLineBreak:
+		return "<br />"
+	case *SoftLineBreak:
+		return "\n"
+	case *CodeSpan:
+		return "<code>" + htmlEscaper.Replace(v.Code) + "</code>"
+	case *InlineImage:
+		result += `<img src="` + htmlEscaper.Replace(escapeURL(v.Destination())) + `" alt="` + htmlEscaper.Replace(renderImageAltText(v.Children)) + `"`
+		if title := v.Title(); title != "" {
+			result += ` title="` + htmlEscaper.Replace(title) + `"`
+		}
+		result += ` />`
+	case *ReferenceImage:
+		result += `<img src="` + htmlEscaper.Replace(escapeURL(v.Destination())) + `" alt="` + htmlEscaper.Replace(renderImageAltText(v.Children)) + `"`
+		if title := v.Title(); title != "" {
+			result += ` title="` + htmlEscaper.Replace(title) + `"`
+		}
+		result += ` />`
+	case *InlineLink:
+		result += `<a href="` + htmlEscaper.Replace(escapeURL(v.Destination())) + `"`
+		if title := v.Title(); title != "" {
+			result += ` title="` + htmlEscaper.Replace(title) + `"`
+		}
+		result += `>`
+		for _, inline := range v.Children {
+			result += RenderInlineHTML(inline)
+		}
+		result += "</a>"
+	case *ReferenceLink:
+		result += `<a href="` + htmlEscaper.Replace(escapeURL(v.Destination())) + `"`
+		if title := v.Title(); title != "" {
+			result += ` title="` + htmlEscaper.Replace(title) + `"`
+		}
+		result += `>`
+		for _, inline := range v.Children {
+			result += RenderInlineHTML(inline)
+		}
+		result += "</a>"
+	case *Autolink:
+		result += `<a href="` + htmlEscaper.Replace(escapeURL(v.Destination())) + `">`
+		for _, inline := range v.Children {
+			result += RenderInlineHTML(inline)
+		}
+		result += "</a>"
+	default:
+		panic(fmt.Sprintf("missing case for type %T", v))
+	}
+	return
+}
+
+func renderImageAltText(children []Inline) (result string) {
+	for _, inline := range children {
+		result += renderImageChildAltText(inline)
+	}
+	return
+}
+
+func renderImageChildAltText(inline Inline) (result string) {
+	switch v := inline.(type) {
+	case *Text:
+		return v.Text
+	case *InlineImage:
+		for _, inline := range v.Children {
+			result += renderImageChildAltText(inline)
+		}
+	case *InlineLink:
+		for _, inline := range v.Children {
+			result += renderImageChildAltText(inline)
+		}
+	}
+	return
+}

vendor/github.com/mattermost/mattermost-server/v5/shared/markdown/indented_code.go

@@ -0,0 +1,98 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package markdown
+
+import (
+	"strings"
+)
+
+type IndentedCodeLine struct {
+	Indentation int
+	Range       Range
+}
+
+type IndentedCode struct {
+	blockBase
+	markdown string
+
+	RawCode []IndentedCodeLine
+}
+
+func (b *IndentedCode) Code() (result string) {
+	for _, code := range b.RawCode {
+		result += strings.Repeat(" ", code.Indentation) + b.markdown[code.Range.Position:code.Range.End]
+	}
+	return
+}
+
+func (b *IndentedCode) Continuation(indentation int, r Range) *continuation {
+	if indentation >= 4 {
+		return &continuation{
+			Indentation: indentation - 4,
+			Remaining:   r,
+		}
+	}
+	s := b.markdown[r.Position:r.End]
+	if strings.TrimSpace(s) == "" {
+		return &continuation{
+			Remaining: r,
+		}
+	}
+	return nil
+}
+
+func (b *IndentedCode) AddLine(indentation int, r Range) bool {
+	b.RawCode = append(b.RawCode, IndentedCodeLine{
+		Indentation: indentation,
+		Range:       r,
+	})
+	return true
+}
+
+func (b *IndentedCode) Close() {
+	for {
+		last := b.RawCode[len(b.RawCode)-1]
+		s := b.markdown[last.Range.Position:last.Range.End]
+		if strings.TrimRight(s, "\r\n") == "" {
+			b.RawCode = b.RawCode[:len(b.RawCode)-1]
+		} else {
+			break
+		}
+	}
+}
+
+func (b *IndentedCode) AllowsBlockStarts() bool {
+	return false
+}
+
+func indentedCodeStart(markdown string, indentation int, r Range, matchedBlocks, unmatchedBlocks []Block) []Block {
+	if len(unmatchedBlocks) > 0 {
+		if _, ok := unmatchedBlocks[len(unmatchedBlocks)-1].(*Paragraph); ok {
+			return nil
+		}
+	} else if len(matchedBlocks) > 0 {
+		if _, ok := matchedBlocks[len(matchedBlocks)-1].(*Paragraph); ok {
+			return nil
+		}
+	}
+
+	if indentation < 4 {
+		return nil
+	}
+
+	s := markdown[r.Position:r.End]
+	if strings.TrimSpace(s) == "" {
+		return nil
+	}
+
+	return []Block{
+		&IndentedCode{
+			markdown: markdown,
+			RawCode: []IndentedCodeLine{{
+				Indentation: indentation - 4,
+				Range:       r,
+			}},
+		},
+	}
+}

vendor/github.com/mattermost/mattermost-server/v5/shared/markdown/inlines.go

@@ -0,0 +1,663 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package markdown
+
+import (
+	"container/list"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+)
+
+type Inline interface {
+	IsInline() bool
+}
+
+type inlineBase struct{}
+
+func (inlineBase) IsInline() bool { return true }
+
+type Text struct {
+	inlineBase
+
+	Text  string
+	Range Range
+}
+
+type CodeSpan struct {
+	inlineBase
+
+	Code string
+}
+
+type HardLineBreak struct {
+	inlineBase
+}
+
+type SoftLineBreak struct {
+	inlineBase
+}
+
+type InlineLinkOrImage struct {
+	inlineBase
+
+	Children []Inline
+
+	RawDestination Range
+
+	markdown string
+	rawTitle string
+}
+
+func (i *InlineLinkOrImage) Destination() string {
+	return Unescape(i.markdown[i.RawDestination.Position:i.RawDestination.End])
+}
+
+func (i *InlineLinkOrImage) Title() string {
+	return Unescape(i.rawTitle)
+}
+
+type InlineLink struct {
+	InlineLinkOrImage
+}
+
+type InlineImage struct {
+	InlineLinkOrImage
+}
+
+type ReferenceLinkOrImage struct {
+	inlineBase
+	*ReferenceDefinition
+
+	Children []Inline
+}
+
+type ReferenceLink struct {
+	ReferenceLinkOrImage
+}
+
+type ReferenceImage struct {
+	ReferenceLinkOrImage
+}
+
+type Autolink struct {
+	inlineBase
+
+	Children []Inline
+
+	RawDestination Range
+
+	markdown string
+}
+
+func (i *Autolink) Destination() string {
+	destination := Unescape(i.markdown[i.RawDestination.Position:i.RawDestination.End])
+
+	if strings.HasPrefix(destination, "www") {
+		destination = "http://" + destination
+	}
+
+	return destination
+}
+
+type delimiterType int
+
+const (
+	linkOpeningDelimiter delimiterType = iota
+	imageOpeningDelimiter
+)
+
+type delimiter struct {
+	Type       delimiterType
+	IsInactive bool
+	TextNode   int
+	Range      Range
+}
+
+type inlineParser struct {
+	markdown             string
+	ranges               []Range
+	referenceDefinitions []*ReferenceDefinition
+
+	raw            string
+	position       int
+	inlines        []Inline
+	delimiterStack *list.List
+}
+
+func newInlineParser(markdown string, ranges []Range, referenceDefinitions []*ReferenceDefinition) *inlineParser {
+	return &inlineParser{
+		markdown:             markdown,
+		ranges:               ranges,
+		referenceDefinitions: referenceDefinitions,
+		delimiterStack:       list.New(),
+	}
+}
+
+func (p *inlineParser) parseBackticks() {
+	count := 1
+	for i := p.position + 1; i < len(p.raw) && p.raw[i] == '`'; i++ {
+		count++
+	}
+	opening := p.raw[p.position : p.position+count]
+	search := p.position + count
+	for search < len(p.raw) {
+		end := strings.Index(p.raw[search:], opening)
+		if end == -1 {
+			break
+		}
+		if search+end+count < len(p.raw) && p.raw[search+end+count] == '`' {
+			search += end + count
+			for search < len(p.raw) && p.raw[search] == '`' {
+				search++
+			}
+			continue
+		}
+		code := strings.Join(strings.Fields(p.raw[p.position+count:search+end]), " ")
+		p.position = search + end + count
+		p.inlines = append(p.inlines, &CodeSpan{
+			Code: code,
+		})
+		return
+	}
+	p.position += len(opening)
+	absPos := relativeToAbsolutePosition(p.ranges, p.position-len(opening))
+	p.inlines = append(p.inlines, &Text{
+		Text:  opening,
+		Range: Range{absPos, absPos + len(opening)},
+	})
+}
+
+func (p *inlineParser) parseLineEnding() {
+	if p.position >= 1 && p.raw[p.position-1] == '\t' {
+		p.inlines = append(p.inlines, &HardLineBreak{})
+	} else if p.position >= 2 && p.raw[p.position-1] == ' ' && (p.raw[p.position-2] == '\t' || p.raw[p.position-1] == ' ') {
+		p.inlines = append(p.inlines, &HardLineBreak{})
+	} else {
+		p.inlines = append(p.inlines, &SoftLineBreak{})
+	}
+	p.position++
+	if p.position < len(p.raw) && p.raw[p.position] == '\n' {
+		p.position++
+	}
+}
+
+func (p *inlineParser) parseEscapeCharacter() {
+	if p.position+1 < len(p.raw) && isEscapableByte(p.raw[p.position+1]) {
+		absPos := relativeToAbsolutePosition(p.ranges, p.position+1)
+		p.inlines = append(p.inlines, &Text{
+			Text:  string(p.raw[p.position+1]),
+			Range: Range{absPos, absPos + len(string(p.raw[p.position+1]))},
+		})
+		p.position += 2
+	} else {
+		absPos := relativeToAbsolutePosition(p.ranges, p.position)
+		p.inlines = append(p.inlines, &Text{
+			Text:  `\`,
+			Range: Range{absPos, absPos + 1},
+		})
+		p.position++
+	}
+}
+
+func (p *inlineParser) parseText() {
+	if next := strings.IndexAny(p.raw[p.position:], "\r\n\\`&![]wW:"); next == -1 {
+		absPos := relativeToAbsolutePosition(p.ranges, p.position)
+		p.inlines = append(p.inlines, &Text{
+			Text:  strings.TrimRightFunc(p.raw[p.position:], isWhitespace),
+			Range: Range{absPos, absPos + len(p.raw[p.position:])},
+		})
+		p.position = len(p.raw)
+	} else {
+		absPos := relativeToAbsolutePosition(p.ranges, p.position)
+		if p.raw[p.position+next] == '\r' || p.raw[p.position+next] == '\n' {
+			s := strings.TrimRightFunc(p.raw[p.position:p.position+next], isWhitespace)
+			p.inlines = append(p.inlines, &Text{
+				Text:  s,
+				Range: Range{absPos, absPos + len(s)},
+			})
+		} else {
+			if next == 0 {
+				// Always read at least one character since 'w', 'W', and ':' may not actually match another
+				// type of node
+				next = 1
+			}
+
+			p.inlines = append(p.inlines, &Text{
+				Text:  p.raw[p.position : p.position+next],
+				Range: Range{absPos, absPos + next},
+			})
+		}
+		p.position += next
+	}
+}
+
+func (p *inlineParser) parseLinkOrImageDelimiter() {
+	absPos := relativeToAbsolutePosition(p.ranges, p.position)
+	if p.raw[p.position] == '[' {
+		p.inlines = append(p.inlines, &Text{
+			Text:  "[",
+			Range: Range{absPos, absPos + 1},
+		})
+		p.delimiterStack.PushBack(&delimiter{
+			Type:     linkOpeningDelimiter,
+			TextNode: len(p.inlines) - 1,
+			Range:    Range{p.position, p.position + 1},
+		})
+		p.position++
+	} else if p.raw[p.position] == '!' && p.position+1 < len(p.raw) && p.raw[p.position+1] == '[' {
+		p.inlines = append(p.inlines, &Text{
+			Text:  "![",
+			Range: Range{absPos, absPos + 2},
+		})
+		p.delimiterStack.PushBack(&delimiter{
+			Type:     imageOpeningDelimiter,
+			TextNode: len(p.inlines) - 1,
+			Range:    Range{p.position, p.position + 2},
+		})
+		p.position += 2
+	} else {
+		p.inlines = append(p.inlines, &Text{
+			Text:  "!",
+			Range: Range{absPos, absPos + 1},
+		})
+		p.position++
+	}
+}
+
+func (p *inlineParser) peekAtInlineLinkDestinationAndTitle(position int, isImage bool) (destination, title Range, end int, ok bool) {
+	if position >= len(p.raw) || p.raw[position] != '(' {
+		return
+	}
+	position++
+
+	destinationStart := nextNonWhitespace(p.raw, position)
+	if destinationStart >= len(p.raw) {
+		return
+	} else if p.raw[destinationStart] == ')' {
+		return Range{destinationStart, destinationStart}, Range{destinationStart, destinationStart}, destinationStart + 1, true
+	}
+
+	destination, end, ok = parseLinkDestination(p.raw, destinationStart)
+	if !ok {
+		return
+	}
+	position = end
+
+	if isImage && position < len(p.raw) && isWhitespaceByte(p.raw[position]) {
+		dimensionsStart := nextNonWhitespace(p.raw, position)
+		if dimensionsStart >= len(p.raw) {
+			return
+		}
+
+		if p.raw[dimensionsStart] == '=' {
+			// Read optional image dimensions even if we don't use them
+			_, end, ok = parseImageDimensions(p.raw, dimensionsStart)
+			if !ok {
+				return
+			}
+
+			position = end
+		}
+	}
+
+	if position < len(p.raw) && isWhitespaceByte(p.raw[position]) {
+		titleStart := nextNonWhitespace(p.raw, position)
+		if titleStart >= len(p.raw) {
+			return
+		} else if p.raw[titleStart] == ')' {
+			return destination, Range{titleStart, titleStart}, titleStart + 1, true
+		}
+
+		if p.raw[titleStart] == '"' || p.raw[titleStart] == '\'' || p.raw[titleStart] == '(' {
+			title, end, ok = parseLinkTitle(p.raw, titleStart)
+			if !ok {
+				return
+			}
+			position = end
+		}
+	}
+
+	closingPosition := nextNonWhitespace(p.raw, position)
+	if closingPosition >= len(p.raw) || p.raw[closingPosition] != ')' {
+		return Range{}, Range{}, 0, false
+	}
+
+	return destination, title, closingPosition + 1, true
+}
+
+func (p *inlineParser) referenceDefinition(label string) *ReferenceDefinition {
+	clean := strings.Join(strings.Fields(label), " ")
+	for _, d := range p.referenceDefinitions {
+		if strings.EqualFold(clean, strings.Join(strings.Fields(d.Label()), " ")) {
+			return d
+		}
+	}
+	return nil
+}
+
+func (p *inlineParser) lookForLinkOrImage() {
+	for element := p.delimiterStack.Back(); element != nil; element = element.Prev() {
+		d := element.Value.(*delimiter)
+		if d.Type != imageOpeningDelimiter && d.Type != linkOpeningDelimiter {
+			continue
+		}
+		if d.IsInactive {
+			p.delimiterStack.Remove(element)
+			break
+		}
+
+		isImage := d.Type == imageOpeningDelimiter
+
+		var inline Inline
+
+		if destination, title, next, ok := p.peekAtInlineLinkDestinationAndTitle(p.position+1, isImage); ok {
+			destinationMarkdownPosition := relativeToAbsolutePosition(p.ranges, destination.Position)
+			linkOrImage := InlineLinkOrImage{
+				Children:       append([]Inline(nil), p.inlines[d.TextNode+1:]...),
+				RawDestination: Range{destinationMarkdownPosition, destinationMarkdownPosition + destination.End - destination.Position},
+				markdown:       p.markdown,
+				rawTitle:       p.raw[title.Position:title.End],
+			}
+			if d.Type == imageOpeningDelimiter {
+				inline = &InlineImage{linkOrImage}
+			} else {
+				inline = &InlineLink{linkOrImage}
+			}
+			p.position = next
+		} else {
+			referenceLabel := ""
+			label, next, hasLinkLabel := parseLinkLabel(p.raw, p.position+1)
+			if hasLinkLabel && label.End > label.Position {
+				referenceLabel = p.raw[label.Position:label.End]
+			} else {
+				referenceLabel = p.raw[d.Range.End:p.position]
+				if !hasLinkLabel {
+					next = p.position + 1
+				}
+			}
+			if referenceLabel != "" {
+				if reference := p.referenceDefinition(referenceLabel); reference != nil {
+					linkOrImage := ReferenceLinkOrImage{
+						ReferenceDefinition: reference,
+						Children:            append([]Inline(nil), p.inlines[d.TextNode+1:]...),
+					}
+					if d.Type == imageOpeningDelimiter {
+						inline = &ReferenceImage{linkOrImage}
+					} else {
+						inline = &ReferenceLink{linkOrImage}
+					}
+					p.position = next
+				}
+			}
+		}
+
+		if inline != nil {
+			if d.Type == imageOpeningDelimiter {
+				p.inlines = append(p.inlines[:d.TextNode], inline)
+			} else {
+				p.inlines = append(p.inlines[:d.TextNode], inline)
+				for inlineElement := element.Prev(); inlineElement != nil; inlineElement = inlineElement.Prev() {
+					if d := inlineElement.Value.(*delimiter); d.Type == linkOpeningDelimiter {
+						d.IsInactive = true
+					}
+				}
+			}
+			p.delimiterStack.Remove(element)
+			return
+		}
+		p.delimiterStack.Remove(element)
+		break
+	}
+	absPos := relativeToAbsolutePosition(p.ranges, p.position)
+	p.inlines = append(p.inlines, &Text{
+		Text:  "]",
+		Range: Range{absPos, absPos + 1},
+	})
+	p.position++
+}
+
+func CharacterReference(ref string) string {
+	if ref == "" {
+		return ""
+	}
+	if ref[0] == '#' {
+		if len(ref) < 2 {
+			return ""
+		}
+		n := 0
+		if ref[1] == 'X' || ref[1] == 'x' {
+			if len(ref) < 3 {
+				return ""
+			}
+			for i := 2; i < len(ref); i++ {
+				if i > 9 {
+					return ""
+				}
+				d := ref[i]
+				switch {
+				case d >= '0' && d <= '9':
+					n = n*16 + int(d-'0')
+				case d >= 'a' && d <= 'f':
+					n = n*16 + 10 + int(d-'a')
+				case d >= 'A' && d <= 'F':
+					n = n*16 + 10 + int(d-'A')
+				default:
+					return ""
+				}
+			}
+		} else {
+			for i := 1; i < len(ref); i++ {
+				if i > 8 || ref[i] < '0' || ref[i] > '9' {
+					return ""
+				}
+				n = n*10 + int(ref[i]-'0')
+			}
+		}
+		c := rune(n)
+		if c == '\u0000' || !utf8.ValidRune(c) {
+			return string(unicode.ReplacementChar)
+		}
+		return string(c)
+	}
+	if entity, ok := htmlEntities[ref]; ok {
+		return entity
+	}
+	return ""
+}
+
+func (p *inlineParser) parseCharacterReference() {
+	absPos := relativeToAbsolutePosition(p.ranges, p.position)
+	p.position++
+	if semicolon := strings.IndexByte(p.raw[p.position:], ';'); semicolon == -1 {
+		p.inlines = append(p.inlines, &Text{
+			Text:  "&",
+			Range: Range{absPos, absPos + 1},
+		})
+	} else if s := CharacterReference(p.raw[p.position : p.position+semicolon]); s != "" {
+		p.position += semicolon + 1
+		p.inlines = append(p.inlines, &Text{
+			Text:  s,
+			Range: Range{absPos, absPos + len(s)},
+		})
+	} else {
+		p.inlines = append(p.inlines, &Text{
+			Text:  "&",
+			Range: Range{absPos, absPos + 1},
+		})
+	}
+}
+
+func (p *inlineParser) parseAutolink(c rune) bool {
+	for element := p.delimiterStack.Back(); element != nil; element = element.Prev() {
+		d := element.Value.(*delimiter)
+		if !d.IsInactive {
+			return false
+		}
+	}
+
+	var link Range
+	if c == ':' {
+		var ok bool
+		link, ok = parseURLAutolink(p.raw, p.position)
+
+		if !ok {
+			return false
+		}
+
+		// Since the current position is at the colon, we have to rewind the parsing slightly so that
+		// we don't duplicate the URL scheme
+		rewind := strings.Index(p.raw[link.Position:link.End], ":")
+		if rewind != -1 {
+			lastInline := p.inlines[len(p.inlines)-1]
+			lastText, ok := lastInline.(*Text)
+
+			if !ok {
+				// This should never occur since parseURLAutolink will only return a non-empty value
+				// when the previous text ends in a valid URL protocol which would mean that the previous
+				// node is a Text node
+				return false
+			}
+
+			p.inlines = p.inlines[0 : len(p.inlines)-1]
+			p.inlines = append(p.inlines, &Text{
+				Text:  lastText.Text[:len(lastText.Text)-rewind],
+				Range: Range{lastText.Range.Position, lastText.Range.End - rewind},
+			})
+			p.position -= rewind
+		}
+	} else if c == 'w' || c == 'W' {
+		var ok bool
+		link, ok = parseWWWAutolink(p.raw, p.position)
+
+		if !ok {
+			return false
+		}
+	}
+
+	linkMarkdownPosition := relativeToAbsolutePosition(p.ranges, link.Position)
+	linkRange := Range{linkMarkdownPosition, linkMarkdownPosition + link.End - link.Position}
+
+	p.inlines = append(p.inlines, &Autolink{
+		Children: []Inline{
+			&Text{
+				Text:  p.raw[link.Position:link.End],
+				Range: linkRange,
+			},
+		},
+		RawDestination: linkRange,
+		markdown:       p.markdown,
+	})
+	p.position += (link.End - link.Position)
+
+	return true
+}
+
+func (p *inlineParser) Parse() []Inline {
+	for _, r := range p.ranges {
+		p.raw += p.markdown[r.Position:r.End]
+	}
+
+	for p.position < len(p.raw) {
+		c, _ := utf8.DecodeRuneInString(p.raw[p.position:])
+
+		switch c {
+		case '\r', '\n':
+			p.parseLineEnding()
+		case '\\':
+			p.parseEscapeCharacter()
+		case '`':
+			p.parseBackticks()
+		case '&':
+			p.parseCharacterReference()
+		case '!', '[':
+			p.parseLinkOrImageDelimiter()
+		case ']':
+			p.lookForLinkOrImage()
+		case 'w', 'W', ':':
+			matched := p.parseAutolink(c)
+
+			if !matched {
+				p.parseText()
+			}
+		default:
+			p.parseText()
+		}
+	}
+
+	return p.inlines
+}
+
+func ParseInlines(markdown string, ranges []Range, referenceDefinitions []*ReferenceDefinition) (inlines []Inline) {
+	return newInlineParser(markdown, ranges, referenceDefinitions).Parse()
+}
+
+func MergeInlineText(inlines []Inline) []Inline {
+	ret := inlines[:0]
+	for i, v := range inlines {
+		// always add first node
+		if i == 0 {
+			ret = append(ret, v)
+			continue
+		}
+		// not a text node? nothing to merge
+		text, ok := v.(*Text)
+		if !ok {
+			ret = append(ret, v)
+			continue
+		}
+		// previous node is not a text node? nothing to merge
+		prevText, ok := ret[len(ret)-1].(*Text)
+		if !ok {
+			ret = append(ret, v)
+			continue
+		}
+		// previous node is not right before this one
+		if prevText.Range.End != text.Range.Position {
+			ret = append(ret, v)
+			continue
+		}
+		// we have two consecutive text nodes
+		ret[len(ret)-1] = &Text{
+			Text:  prevText.Text + text.Text,
+			Range: Range{prevText.Range.Position, text.Range.End},
+		}
+	}
+	return ret
+}
+
+func Unescape(markdown string) string {
+	ret := ""
+
+	position := 0
+	for position < len(markdown) {
+		c, cSize := utf8.DecodeRuneInString(markdown[position:])
+
+		switch c {
+		case '\\':
+			if position+1 < len(markdown) && isEscapableByte(markdown[position+1]) {
+				ret += string(markdown[position+1])
+				position += 2
+			} else {
+				ret += `\`
+				position++
+			}
+		case '&':
+			position++
+			if semicolon := strings.IndexByte(markdown[position:], ';'); semicolon == -1 {
+				ret += "&"
+			} else if s := CharacterReference(markdown[position : position+semicolon]); s != "" {
+				position += semicolon + 1
+				ret += s
+			} else {
+				ret += "&"
+			}
+		default:
+			ret += string(c)
+			position += cSize
+		}
+	}
+
+	return ret
+}

vendor/github.com/mattermost/mattermost-server/v5/shared/markdown/inspect.go

@@ -0,0 +1,78 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package markdown
+
+// Inspect traverses the markdown tree in depth-first order. If f returns true, Inspect invokes f
+// recursively for each child of the block or inline, followed by a call of f(nil).
+func Inspect(markdown string, f func(interface{}) bool) {
+	document, referenceDefinitions := Parse(markdown)
+	InspectBlock(document, func(block Block) bool {
+		if !f(block) {
+			return false
+		}
+		switch v := block.(type) {
+		case *Paragraph:
+			for _, inline := range MergeInlineText(v.ParseInlines(referenceDefinitions)) {
+				InspectInline(inline, func(inline Inline) bool {
+					return f(inline)
+				})
+			}
+		}
+		return true
+	})
+}
+
+// InspectBlock traverses the blocks in depth-first order, starting with block. If f returns true,
+// InspectBlock invokes f recursively for each child of the block, followed by a call of f(nil).
+func InspectBlock(block Block, f func(Block) bool) {
+	if !f(block) {
+		return
+	}
+	switch v := block.(type) {
+	case *Document:
+		for _, child := range v.Children {
+			InspectBlock(child, f)
+		}
+	case *List:
+		for _, child := range v.Children {
+			InspectBlock(child, f)
+		}
+	case *ListItem:
+		for _, child := range v.Children {
+			InspectBlock(child, f)
+		}
+	case *BlockQuote:
+		for _, child := range v.Children {
+			InspectBlock(child, f)
+		}
+	}
+	f(nil)
+}
+
+// InspectInline traverses the blocks in depth-first order, starting with block. If f returns true,
+// InspectInline invokes f recursively for each child of the block, followed by a call of f(nil).
+func InspectInline(inline Inline, f func(Inline) bool) {
+	if !f(inline) {
+		return
+	}
+	switch v := inline.(type) {
+	case *InlineImage:
+		for _, child := range v.Children {
+			InspectInline(child, f)
+		}
+	case *InlineLink:
+		for _, child := range v.Children {
+			InspectInline(child, f)
+		}
+	case *ReferenceImage:
+		for _, child := range v.Children {
+			InspectInline(child, f)
+		}
+	case *ReferenceLink:
+		for _, child := range v.Children {
+			InspectInline(child, f)
+		}
+	}
+	f(nil)
+}

vendor/github.com/mattermost/mattermost-server/v5/shared/markdown/lines.go

@@ -0,0 +1,32 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package markdown
+
+import (
+	"strings"
+)
+
+type Line struct {
+	Range
+}
+
+func ParseLines(markdown string) []Line {
+	lineStartPosition := 0
+	isAfterCarriageReturn := false
+	lines := make([]Line, 0, strings.Count(markdown, "\n"))
+	for position, r := range markdown {
+		if r == '\n' {
+			lines = append(lines, Line{Range{lineStartPosition, position + 1}})
+			lineStartPosition = position + 1
+		} else if isAfterCarriageReturn {
+			lines = append(lines, Line{Range{lineStartPosition, position}})
+			lineStartPosition = position
+		}
+		isAfterCarriageReturn = r == '\r'
+	}
+	if lineStartPosition < len(markdown) {
+		lines = append(lines, Line{Range{lineStartPosition, len(markdown)}})
+	}
+	return lines
+}

vendor/github.com/mattermost/mattermost-server/v5/shared/markdown/links.go

@@ -0,0 +1,184 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package markdown
+
+import (
+	"unicode/utf8"
+)
+
+func parseLinkDestination(markdown string, position int) (raw Range, next int, ok bool) {
+	if position >= len(markdown) {
+		return
+	}
+
+	if markdown[position] == '<' {
+		isEscaped := false
+
+		for offset, c := range []byte(markdown[position+1:]) {
+			if isEscaped {
+				isEscaped = false
+				if isEscapableByte(c) {
+					continue
+				}
+			}
+
+			if c == '\\' {
+				isEscaped = true
+			} else if c == '<' {
+				break
+			} else if c == '>' {
+				return Range{position + 1, position + 1 + offset}, position + 1 + offset + 1, true
+			} else if isWhitespaceByte(c) {
+				break
+			}
+		}
+	}
+
+	openCount := 0
+	isEscaped := false
+	for offset, c := range []byte(markdown[position:]) {
+		if isEscaped {
+			isEscaped = false
+			if isEscapableByte(c) {
+				continue
+			}
+		}
+
+		switch c {
+		case '\\':
+			isEscaped = true
+		case '(':
+			openCount++
+		case ')':
+			if openCount < 1 {
+				return Range{position, position + offset}, position + offset, true
+			}
+			openCount--
+		default:
+			if isWhitespaceByte(c) {
+				return Range{position, position + offset}, position + offset, true
+			}
+		}
+	}
+	return Range{position, len(markdown)}, len(markdown), true
+}
+
+func parseLinkTitle(markdown string, position int) (raw Range, next int, ok bool) {
+	if position >= len(markdown) {
+		return
+	}
+
+	originalPosition := position
+
+	var closer byte
+	switch markdown[position] {
+	case '"', '\'':
+		closer = markdown[position]
+	case '(':
+		closer = ')'
+	default:
+		return
+	}
+	position++
+
+	for position < len(markdown) {
+		switch markdown[position] {
+		case '\\':
+			position++
+			if position < len(markdown) && isEscapableByte(markdown[position]) {
+				position++
+			}
+		case closer:
+			return Range{originalPosition + 1, position}, position + 1, true
+		default:
+			position++
+		}
+	}
+
+	return
+}
+
+func parseLinkLabel(markdown string, position int) (raw Range, next int, ok bool) {
+	if position >= len(markdown) || markdown[position] != '[' {
+		return
+	}
+
+	originalPosition := position
+	position++
+
+	for position < len(markdown) {
+		switch markdown[position] {
+		case '\\':
+			position++
+			if position < len(markdown) && isEscapableByte(markdown[position]) {
+				position++
+			}
+		case '[':
+			return
+		case ']':
+			if position-originalPosition >= 1000 && utf8.RuneCountInString(markdown[originalPosition:position]) >= 1000 {
+				return
+			}
+			return Range{originalPosition + 1, position}, position + 1, true
+		default:
+			position++
+		}
+	}
+
+	return
+}
+
+// As a non-standard feature, we allow image links to specify dimensions of the image by adding "=WIDTHxHEIGHT"
+// after the image destination but before the image title like ![alt](http://example.com/image.png =100x200 "title").
+// Both width and height are optional, but at least one of them must be specified.
+func parseImageDimensions(markdown string, position int) (raw Range, next int, ok bool) {
+	if position >= len(markdown) {
+		return
+	}
+
+	originalPosition := position
+
+	// Read =
+	position += 1
+	if position >= len(markdown) {
+		return
+	}
+
+	// Read width
+	hasWidth := false
+	for position < len(markdown)-1 && isNumericByte(markdown[position]) {
+		hasWidth = true
+		position += 1
+	}
+
+	// Look for early end of dimensions
+	if isWhitespaceByte(markdown[position]) || markdown[position] == ')' {
+		return Range{originalPosition, position - 1}, position, true
+	}
+
+	// Read the x
+	if (markdown[position] != 'x' && markdown[position] != 'X') || position == len(markdown)-1 {
+		return
+	}
+	position += 1
+
+	// Read height
+	hasHeight := false
+	for position < len(markdown)-1 && isNumericByte(markdown[position]) {
+		hasHeight = true
+		position += 1
+	}
+
+	// Make sure the there's no trailing characters
+	if !isWhitespaceByte(markdown[position]) && markdown[position] != ')' {
+		return
+	}
+
+	if !hasWidth && !hasHeight {
+		// At least one of width or height is required
+		return
+	}
+
+	return Range{originalPosition, position - 1}, position, true
+}

vendor/github.com/mattermost/mattermost-server/v5/shared/markdown/list.go

@@ -0,0 +1,220 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package markdown
+
+import (
+	"strings"
+)
+
+type ListItem struct {
+	blockBase
+	markdown                    string
+	hasTrailingBlankLine        bool
+	hasBlankLineBetweenChildren bool
+
+	Indentation int
+	Children    []Block
+}
+
+func (b *ListItem) Continuation(indentation int, r Range) *continuation {
+	s := b.markdown[r.Position:r.End]
+	if strings.TrimSpace(s) == "" {
+		if b.Children == nil {
+			return nil
+		}
+		return &continuation{
+			Remaining: r,
+		}
+	}
+	if indentation < b.Indentation {
+		return nil
+	}
+	return &continuation{
+		Indentation: indentation - b.Indentation,
+		Remaining:   r,
+	}
+}
+
+func (b *ListItem) AddChild(openBlocks []Block) []Block {
+	b.Children = append(b.Children, openBlocks[0])
+	if b.hasTrailingBlankLine {
+		b.hasBlankLineBetweenChildren = true
+	}
+	b.hasTrailingBlankLine = false
+	return openBlocks
+}
+
+func (b *ListItem) AddLine(indentation int, r Range) bool {
+	isBlank := strings.TrimSpace(b.markdown[r.Position:r.End]) == ""
+	if isBlank {
+		b.hasTrailingBlankLine = true
+	}
+	return false
+}
+
+func (b *ListItem) HasTrailingBlankLine() bool {
+	return b.hasTrailingBlankLine || (len(b.Children) > 0 && b.Children[len(b.Children)-1].HasTrailingBlankLine())
+}
+
+func (b *ListItem) isLoose() bool {
+	if b.hasBlankLineBetweenChildren {
+		return true
+	}
+	for i, child := range b.Children {
+		if i < len(b.Children)-1 && child.HasTrailingBlankLine() {
+			return true
+		}
+	}
+	return false
+}
+
+type List struct {
+	blockBase
+	markdown                    string
+	hasTrailingBlankLine        bool
+	hasBlankLineBetweenChildren bool
+
+	IsLoose           bool
+	IsOrdered         bool
+	OrderedStart      int
+	BulletOrDelimiter byte
+	Children          []*ListItem
+}
+
+func (b *List) Continuation(indentation int, r Range) *continuation {
+	s := b.markdown[r.Position:r.End]
+	if strings.TrimSpace(s) == "" {
+		return &continuation{
+			Remaining: r,
+		}
+	}
+	return &continuation{
+		Indentation: indentation,
+		Remaining:   r,
+	}
+}
+
+func (b *List) AddChild(openBlocks []Block) []Block {
+	if item, ok := openBlocks[0].(*ListItem); ok {
+		b.Children = append(b.Children, item)
+		if b.hasTrailingBlankLine {
+			b.hasBlankLineBetweenChildren = true
+		}
+		b.hasTrailingBlankLine = false
+		return openBlocks
+	} else if list, ok := openBlocks[0].(*List); ok {
+		if len(list.Children) == 1 && list.IsOrdered == b.IsOrdered && list.BulletOrDelimiter == b.BulletOrDelimiter {
+			return b.AddChild(openBlocks[1:])
+		}
+	}
+	return nil
+}
+
+func (b *List) AddLine(indentation int, r Range) bool {
+	isBlank := strings.TrimSpace(b.markdown[r.Position:r.End]) == ""
+	if isBlank {
+		b.hasTrailingBlankLine = true
+	}
+	return false
+}
+
+func (b *List) HasTrailingBlankLine() bool {
+	return b.hasTrailingBlankLine || (len(b.Children) > 0 && b.Children[len(b.Children)-1].HasTrailingBlankLine())
+}
+
+func (b *List) isLoose() bool {
+	if b.hasBlankLineBetweenChildren {
+		return true
+	}
+	for i, child := range b.Children {
+		if child.isLoose() || (i < len(b.Children)-1 && child.HasTrailingBlankLine()) {
+			return true
+		}
+	}
+	return false
+}
+
+func (b *List) Close() {
+	b.IsLoose = b.isLoose()
+}
+
+func parseListMarker(markdown string, r Range) (success, isOrdered bool, orderedStart int, bulletOrDelimiter byte, markerWidth int, remaining Range) {
+	digits := 0
+	n := 0
+	for i := r.Position; i < r.End && markdown[i] >= '0' && markdown[i] <= '9'; i++ {
+		digits++
+		n = n*10 + int(markdown[i]-'0')
+	}
+	if digits > 0 {
+		if digits > 9 || r.Position+digits >= r.End {
+			return
+		}
+		next := markdown[r.Position+digits]
+		if next != '.' && next != ')' {
+			return
+		}
+		return true, true, n, next, digits + 1, Range{r.Position + digits + 1, r.End}
+	}
+	if r.Position >= r.End {
+		return
+	}
+	next := markdown[r.Position]
+	if next != '-' && next != '+' && next != '*' {
+		return
+	}
+	return true, false, 0, next, 1, Range{r.Position + 1, r.End}
+}
+
+func listStart(markdown string, indent int, r Range, matchedBlocks, unmatchedBlocks []Block) []Block {
+	afterList := false
+	if len(matchedBlocks) > 0 {
+		_, afterList = matchedBlocks[len(matchedBlocks)-1].(*List)
+	}
+	if !afterList && indent > 3 {
+		return nil
+	}
+
+	success, isOrdered, orderedStart, bulletOrDelimiter, markerWidth, remaining := parseListMarker(markdown, r)
+	if !success {
+		return nil
+	}
+
+	isBlank := strings.TrimSpace(markdown[remaining.Position:remaining.End]) == ""
+	if len(matchedBlocks) > 0 && len(unmatchedBlocks) == 0 {
+		if _, ok := matchedBlocks[len(matchedBlocks)-1].(*Paragraph); ok {
+			if isBlank || (isOrdered && orderedStart != 1) {
+				return nil
+			}
+		}
+	}
+
+	indentAfterMarker, indentBytesAfterMarker := countIndentation(markdown, remaining)
+	if !isBlank && indentAfterMarker < 1 {
+		return nil
+	}
+
+	remaining = Range{remaining.Position + indentBytesAfterMarker, remaining.End}
+	consumedIndentAfterMarker := indentAfterMarker
+	if isBlank || indentAfterMarker >= 5 {
+		consumedIndentAfterMarker = 1
+	}
+
+	listItem := &ListItem{
+		markdown:    markdown,
+		Indentation: indent + markerWidth + consumedIndentAfterMarker,
+	}
+	list := &List{
+		markdown:          markdown,
+		IsOrdered:         isOrdered,
+		OrderedStart:      orderedStart,
+		BulletOrDelimiter: bulletOrDelimiter,
+		Children:          []*ListItem{listItem},
+	}
+	ret := []Block{list, listItem}
+	if descendants := blockStartOrParagraph(markdown, indentAfterMarker-consumedIndentAfterMarker, remaining, nil, nil); descendants != nil {
+		listItem.Children = append(listItem.Children, descendants[0])
+		ret = append(ret, descendants...)
+	}
+	return ret
+}

vendor/github.com/mattermost/mattermost-server/v5/shared/markdown/markdown.go

@@ -0,0 +1,147 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+// This package implements a parser for the subset of the CommonMark spec necessary for us to do
+// server-side processing. It is not a full implementation and lacks many features. But it is
+// complete enough to efficiently and accurately allow us to do what we need to like rewrite image
+// URLs for proxying.
+package markdown
+
+import (
+	"strings"
+)
+
+func isEscapable(c rune) bool {
+	return c > ' ' && (c < '0' || (c > '9' && (c < 'A' || (c > 'Z' && (c < 'a' || (c > 'z' && c <= '~'))))))
+}
+
+func isEscapableByte(c byte) bool {
+	return isEscapable(rune(c))
+}
+
+func isWhitespace(c rune) bool {
+	switch c {
+	case ' ', '\t', '\n', '\u000b', '\u000c', '\r':
+		return true
+	}
+	return false
+}
+
+func isWhitespaceByte(c byte) bool {
+	return isWhitespace(rune(c))
+}
+
+func isNumeric(c rune) bool {
+	return c >= '0' && c <= '9'
+}
+
+func isNumericByte(c byte) bool {
+	return isNumeric(rune(c))
+}
+
+func isHex(c rune) bool {
+	return isNumeric(c) || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F')
+}
+
+func isHexByte(c byte) bool {
+	return isHex(rune(c))
+}
+
+func isAlphanumeric(c rune) bool {
+	return isNumeric(c) || (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')
+}
+
+func isAlphanumericByte(c byte) bool {
+	return isAlphanumeric(rune(c))
+}
+
+func nextNonWhitespace(markdown string, position int) int {
+	for offset, c := range []byte(markdown[position:]) {
+		if !isWhitespaceByte(c) {
+			return position + offset
+		}
+	}
+	return len(markdown)
+}
+
+func nextLine(markdown string, position int) (linePosition int, skippedNonWhitespace bool) {
+	for i := position; i < len(markdown); i++ {
+		c := markdown[i]
+		if c == '\r' {
+			if i+1 < len(markdown) && markdown[i+1] == '\n' {
+				return i + 2, skippedNonWhitespace
+			}
+			return i + 1, skippedNonWhitespace
+		} else if c == '\n' {
+			return i + 1, skippedNonWhitespace
+		} else if !isWhitespaceByte(c) {
+			skippedNonWhitespace = true
+		}
+	}
+	return len(markdown), skippedNonWhitespace
+}
+
+func countIndentation(markdown string, r Range) (spaces, bytes int) {
+	for i := r.Position; i < r.End; i++ {
+		if markdown[i] == ' ' {
+			spaces++
+			bytes++
+		} else if markdown[i] == '\t' {
+			spaces += 4
+			bytes++
+		} else {
+			break
+		}
+	}
+	return
+}
+
+func trimLeftSpace(markdown string, r Range) Range {
+	s := markdown[r.Position:r.End]
+	trimmed := strings.TrimLeftFunc(s, isWhitespace)
+	return Range{r.Position, r.End - (len(s) - len(trimmed))}
+}
+
+func trimRightSpace(markdown string, r Range) Range {
+	s := markdown[r.Position:r.End]
+	trimmed := strings.TrimRightFunc(s, isWhitespace)
+	return Range{r.Position, r.End - (len(s) - len(trimmed))}
+}
+
+func relativeToAbsolutePosition(ranges []Range, position int) int {
+	rem := position
+	for _, r := range ranges {
+		l := r.End - r.Position
+		if rem < l {
+			return r.Position + rem
+		}
+		rem -= l
+	}
+	if len(ranges) == 0 {
+		return 0
+	}
+	return ranges[len(ranges)-1].End
+}
+
+func trimBytesFromRanges(ranges []Range, bytes int) (result []Range) {
+	rem := bytes
+	for _, r := range ranges {
+		if rem == 0 {
+			result = append(result, r)
+			continue
+		}
+		l := r.End - r.Position
+		if rem < l {
+			result = append(result, Range{r.Position + rem, r.End})
+			rem = 0
+			continue
+		}
+		rem -= l
+	}
+	return
+}
+
+func Parse(markdown string) (*Document, []*ReferenceDefinition) {
+	lines := ParseLines(markdown)
+	return ParseBlocks(markdown, lines)
+}

vendor/github.com/mattermost/mattermost-server/v5/shared/markdown/paragraph.go

@@ -0,0 +1,71 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package markdown
+
+import (
+	"strings"
+)
+
+type Paragraph struct {
+	blockBase
+	markdown string
+
+	Text                 []Range
+	ReferenceDefinitions []*ReferenceDefinition
+}
+
+func (b *Paragraph) ParseInlines(referenceDefinitions []*ReferenceDefinition) []Inline {
+	return ParseInlines(b.markdown, b.Text, referenceDefinitions)
+}
+
+func (b *Paragraph) Continuation(indentation int, r Range) *continuation {
+	s := b.markdown[r.Position:r.End]
+	if strings.TrimSpace(s) == "" {
+		return nil
+	}
+	return &continuation{
+		Indentation: indentation,
+		Remaining:   r,
+	}
+}
+
+func (b *Paragraph) Close() {
+	for {
+		for i := 0; i < len(b.Text); i++ {
+			b.Text[i] = trimLeftSpace(b.markdown, b.Text[i])
+			if b.Text[i].Position < b.Text[i].End {
+				break
+			}
+		}
+
+		if len(b.Text) == 0 || b.Text[0].Position < b.Text[0].End && b.markdown[b.Text[0].Position] != '[' {
+			break
+		}
+
+		definition, remaining := parseReferenceDefinition(b.markdown, b.Text)
+		if definition == nil {
+			break
+		}
+		b.ReferenceDefinitions = append(b.ReferenceDefinitions, definition)
+		b.Text = remaining
+	}
+
+	for i := len(b.Text) - 1; i >= 0; i-- {
+		b.Text[i] = trimRightSpace(b.markdown, b.Text[i])
+		if b.Text[i].Position < b.Text[i].End {
+			break
+		}
+	}
+}
+
+func newParagraph(markdown string, r Range) *Paragraph {
+	s := markdown[r.Position:r.End]
+	if strings.TrimSpace(s) == "" {
+		return nil
+	}
+	return &Paragraph{
+		markdown: markdown,
+		Text:     []Range{r},
+	}
+}

vendor/github.com/mattermost/mattermost-server/v5/shared/markdown/reference_definition.go

@@ -0,0 +1,75 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package markdown
+
+type ReferenceDefinition struct {
+	RawDestination Range
+
+	markdown string
+	rawLabel string
+	rawTitle string
+}
+
+func (d *ReferenceDefinition) Destination() string {
+	return Unescape(d.markdown[d.RawDestination.Position:d.RawDestination.End])
+}
+
+func (d *ReferenceDefinition) Label() string {
+	return d.rawLabel
+}
+
+func (d *ReferenceDefinition) Title() string {
+	return Unescape(d.rawTitle)
+}
+
+func parseReferenceDefinition(markdown string, ranges []Range) (*ReferenceDefinition, []Range) {
+	raw := ""
+	for _, r := range ranges {
+		raw += markdown[r.Position:r.End]
+	}
+
+	label, next, ok := parseLinkLabel(raw, 0)
+	if !ok {
+		return nil, nil
+	}
+	position := next
+
+	if position >= len(raw) || raw[position] != ':' {
+		return nil, nil
+	}
+	position++
+
+	destination, next, ok := parseLinkDestination(raw, nextNonWhitespace(raw, position))
+	if !ok {
+		return nil, nil
+	}
+	position = next
+
+	absoluteDestination := relativeToAbsolutePosition(ranges, destination.Position)
+	ret := &ReferenceDefinition{
+		RawDestination: Range{absoluteDestination, absoluteDestination + destination.End - destination.Position},
+		markdown:       markdown,
+		rawLabel:       raw[label.Position:label.End],
+	}
+
+	if position < len(raw) && isWhitespaceByte(raw[position]) {
+		title, next, ok := parseLinkTitle(raw, nextNonWhitespace(raw, position))
+		if !ok {
+			if nextLine, skippedNonWhitespace := nextLine(raw, position); !skippedNonWhitespace {
+				return ret, trimBytesFromRanges(ranges, nextLine)
+			}
+			return nil, nil
+		}
+		if nextLine, skippedNonWhitespace := nextLine(raw, next); !skippedNonWhitespace {
+			ret.rawTitle = raw[title.Position:title.End]
+			return ret, trimBytesFromRanges(ranges, nextLine)
+		}
+	}
+
+	if nextLine, skippedNonWhitespace := nextLine(raw, position); !skippedNonWhitespace {
+		return ret, trimBytesFromRanges(ranges, nextLine)
+	}
+
+	return nil, nil
+}

vendor/github.com/mattermost/mattermost-server/v5/shared/mlog/default.go

@@ -0,0 +1,99 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package mlog
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"os"
+
+	"github.com/mattermost/logr"
+)
+
+// defaultLog manually encodes the log to STDERR, providing a basic, default logging implementation
+// before mlog is fully configured.
+func defaultLog(level, msg string, fields ...Field) {
+	log := struct {
+		Level   string  `json:"level"`
+		Message string  `json:"msg"`
+		Fields  []Field `json:"fields,omitempty"`
+	}{
+		level,
+		msg,
+		fields,
+	}
+
+	if b, err := json.Marshal(log); err != nil {
+		fmt.Fprintf(os.Stderr, `{"level":"error","msg":"failed to encode log message"}%s`, "\n")
+	} else {
+		fmt.Fprintf(os.Stderr, "%s\n", b)
+	}
+}
+
+func defaultIsLevelEnabled(level LogLevel) bool {
+	return true
+}
+
+func defaultDebugLog(msg string, fields ...Field) {
+	defaultLog("debug", msg, fields...)
+}
+
+func defaultInfoLog(msg string, fields ...Field) {
+	defaultLog("info", msg, fields...)
+}
+
+func defaultWarnLog(msg string, fields ...Field) {
+	defaultLog("warn", msg, fields...)
+}
+
+func defaultErrorLog(msg string, fields ...Field) {
+	defaultLog("error", msg, fields...)
+}
+
+func defaultCriticalLog(msg string, fields ...Field) {
+	// We map critical to error in zap, so be consistent.
+	defaultLog("error", msg, fields...)
+}
+
+func defaultCustomLog(lvl LogLevel, msg string, fields ...Field) {
+	// custom log levels are only output once log targets are configured.
+}
+
+func defaultCustomMultiLog(lvl []LogLevel, msg string, fields ...Field) {
+	// custom log levels are only output once log targets are configured.
+}
+
+func defaultFlush(ctx context.Context) error {
+	return nil
+}
+
+func defaultAdvancedConfig(cfg LogTargetCfg) error {
+	// mlog.ConfigAdvancedConfig should not be called until default
+	// logger is replaced with mlog.Logger instance.
+	return errors.New("cannot config advanced logging on default logger")
+}
+
+func defaultAdvancedShutdown(ctx context.Context) error {
+	return nil
+}
+
+func defaultAddTarget(targets ...logr.Target) error {
+	// mlog.AddTarget should not be called until default
+	// logger is replaced with mlog.Logger instance.
+	return errors.New("cannot AddTarget on default logger")
+}
+
+func defaultRemoveTargets(ctx context.Context, f func(TargetInfo) bool) error {
+	// mlog.RemoveTargets should not be called until default
+	// logger is replaced with mlog.Logger instance.
+	return errors.New("cannot RemoveTargets on default logger")
+}
+
+func defaultEnableMetrics(collector logr.MetricsCollector) error {
+	// mlog.EnableMetrics should not be called until default
+	// logger is replaced with mlog.Logger instance.
+	return errors.New("cannot EnableMetrics on default logger")
+}

vendor/github.com/mattermost/mattermost-server/v5/shared/mlog/errors.go

@@ -0,0 +1,32 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package mlog
+
+import (
+	"github.com/mattermost/logr"
+)
+
+// onLoggerError is called when the logging system encounters an error,
+// such as a target not able to write records. The targets will keep trying
+// however the error will be logged with a dedicated level that can be output
+// to a safe/always available target for monitoring or alerting.
+func onLoggerError(err error) {
+	Log(LvlLogError, "advanced logging error", Err(err))
+}
+
+// onQueueFull is called when the main logger queue is full, indicating the
+// volume and frequency of log record creation is too high for the queue size
+// and/or the target latencies.
+func onQueueFull(rec *logr.LogRec, maxQueueSize int) bool {
+	Log(LvlLogError, "main queue full, dropping record", Any("rec", rec))
+	return true // drop record
+}
+
+// onTargetQueueFull is called when the main logger queue is full, indicating the
+// volume and frequency of log record creation is too high for the target's queue size
+// and/or the target latency.
+func onTargetQueueFull(target logr.Target, rec *logr.LogRec, maxQueueSize int) bool {
+	Log(LvlLogError, "target queue full, dropping record", String("target", ""), Any("rec", rec))
+	return true // drop record
+}

vendor/github.com/mattermost/mattermost-server/v5/shared/mlog/global.go

@@ -0,0 +1,98 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package mlog
+
+import (
+	"context"
+	"log"
+	"sync/atomic"
+
+	"github.com/mattermost/logr"
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+)
+
+var globalLogger *Logger
+
+func InitGlobalLogger(logger *Logger) {
+	// Clean up previous instance.
+	if globalLogger != nil && globalLogger.logrLogger != nil {
+		globalLogger.logrLogger.Logr().Shutdown()
+	}
+	glob := *logger
+	glob.zap = glob.zap.WithOptions(zap.AddCallerSkip(1))
+	globalLogger = &glob
+	IsLevelEnabled = globalLogger.IsLevelEnabled
+	Debug = globalLogger.Debug
+	Info = globalLogger.Info
+	Warn = globalLogger.Warn
+	Error = globalLogger.Error
+	Critical = globalLogger.Critical
+	Log = globalLogger.Log
+	LogM = globalLogger.LogM
+	Flush = globalLogger.Flush
+	ConfigAdvancedLogging = globalLogger.ConfigAdvancedLogging
+	ShutdownAdvancedLogging = globalLogger.ShutdownAdvancedLogging
+	AddTarget = globalLogger.AddTarget
+	RemoveTargets = globalLogger.RemoveTargets
+	EnableMetrics = globalLogger.EnableMetrics
+}
+
+// logWriterFunc provides access to mlog via io.Writer, so the standard logger
+// can be redirected to use mlog and whatever targets are defined.
+type logWriterFunc func([]byte) (int, error)
+
+func (lw logWriterFunc) Write(p []byte) (int, error) {
+	return lw(p)
+}
+
+func RedirectStdLog(logger *Logger) {
+	if atomic.LoadInt32(&disableZap) == 0 {
+		zap.RedirectStdLogAt(logger.zap.With(zap.String("source", "stdlog")).WithOptions(zap.AddCallerSkip(-2)), zapcore.ErrorLevel)
+		return
+	}
+
+	writer := func(p []byte) (int, error) {
+		Log(LvlStdLog, string(p))
+		return len(p), nil
+	}
+	log.SetOutput(logWriterFunc(writer))
+}
+
+type IsLevelEnabledFunc func(LogLevel) bool
+type LogFunc func(string, ...Field)
+type LogFuncCustom func(LogLevel, string, ...Field)
+type LogFuncCustomMulti func([]LogLevel, string, ...Field)
+type FlushFunc func(context.Context) error
+type ConfigFunc func(cfg LogTargetCfg) error
+type ShutdownFunc func(context.Context) error
+type AddTargetFunc func(...logr.Target) error
+type RemoveTargetsFunc func(context.Context, func(TargetInfo) bool) error
+type EnableMetricsFunc func(logr.MetricsCollector) error
+
+// DON'T USE THIS Modify the level on the app logger
+func GloballyDisableDebugLogForTest() {
+	globalLogger.consoleLevel.SetLevel(zapcore.ErrorLevel)
+}
+
+// DON'T USE THIS Modify the level on the app logger
+func GloballyEnableDebugLogForTest() {
+	globalLogger.consoleLevel.SetLevel(zapcore.DebugLevel)
+}
+
+var IsLevelEnabled IsLevelEnabledFunc = defaultIsLevelEnabled
+var Debug LogFunc = defaultDebugLog
+var Info LogFunc = defaultInfoLog
+var Warn LogFunc = defaultWarnLog
+var Error LogFunc = defaultErrorLog
+var Critical LogFunc = defaultCriticalLog
+var Log LogFuncCustom = defaultCustomLog
+var LogM LogFuncCustomMulti = defaultCustomMultiLog
+var Flush FlushFunc = defaultFlush
+
+var ConfigAdvancedLogging ConfigFunc = defaultAdvancedConfig
+var ShutdownAdvancedLogging ShutdownFunc = defaultAdvancedShutdown
+var AddTarget AddTargetFunc = defaultAddTarget
+var RemoveTargets RemoveTargetsFunc = defaultRemoveTargets
+var EnableMetrics EnableMetricsFunc = defaultEnableMetrics

vendor/github.com/mattermost/mattermost-server/v5/shared/mlog/levels.go

@@ -0,0 +1,51 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package mlog
+
+// Standard levels
+var (
+	LvlPanic = LogLevel{ID: 0, Name: "panic", Stacktrace: true}
+	LvlFatal = LogLevel{ID: 1, Name: "fatal", Stacktrace: true}
+	LvlError = LogLevel{ID: 2, Name: "error"}
+	LvlWarn  = LogLevel{ID: 3, Name: "warn"}
+	LvlInfo  = LogLevel{ID: 4, Name: "info"}
+	LvlDebug = LogLevel{ID: 5, Name: "debug"}
+	LvlTrace = LogLevel{ID: 6, Name: "trace"}
+	// used by redirected standard logger
+	LvlStdLog = LogLevel{ID: 10, Name: "stdlog"}
+	// used only by the logger
+	LvlLogError = LogLevel{ID: 11, Name: "logerror", Stacktrace: true}
+)
+
+// Register custom (discrete) levels here.
+// !!!!! ID's must not exceed 32,768 !!!!!!
+var (
+	// used by the audit system
+	LvlAuditAPI     = LogLevel{ID: 100, Name: "audit-api"}
+	LvlAuditContent = LogLevel{ID: 101, Name: "audit-content"}
+	LvlAuditPerms   = LogLevel{ID: 102, Name: "audit-permissions"}
+	LvlAuditCLI     = LogLevel{ID: 103, Name: "audit-cli"}
+
+	// used by the TCP log target
+	LvlTcpLogTarget = LogLevel{ID: 120, Name: "TcpLogTarget"}
+
+	// used by Remote Cluster Service
+	LvlRemoteClusterServiceDebug = LogLevel{ID: 130, Name: "RemoteClusterServiceDebug"}
+	LvlRemoteClusterServiceError = LogLevel{ID: 131, Name: "RemoteClusterServiceError"}
+	LvlRemoteClusterServiceWarn  = LogLevel{ID: 132, Name: "RemoteClusterServiceWarn"}
+
+	// used by Shared Channel Sync Service
+	LvlSharedChannelServiceDebug            = LogLevel{ID: 200, Name: "SharedChannelServiceDebug"}
+	LvlSharedChannelServiceError            = LogLevel{ID: 201, Name: "SharedChannelServiceError"}
+	LvlSharedChannelServiceWarn             = LogLevel{ID: 202, Name: "SharedChannelServiceWarn"}
+	LvlSharedChannelServiceMessagesInbound  = LogLevel{ID: 203, Name: "SharedChannelServiceMsgInbound"}
+	LvlSharedChannelServiceMessagesOutbound = LogLevel{ID: 204, Name: "SharedChannelServiceMsgOutbound"}
+
+	// add more here ...
+)
+
+// Combinations for LogM (log multi)
+var (
+	MLvlAuditAll = []LogLevel{LvlAuditAPI, LvlAuditContent, LvlAuditPerms, LvlAuditCLI}
+)

vendor/github.com/mattermost/mattermost-server/v5/shared/mlog/log.go

@@ -0,0 +1,361 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package mlog
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/mattermost/logr"
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+	"gopkg.in/natefinch/lumberjack.v2"
+)
+
+const (
+	// Very verbose messages for debugging specific issues
+	LevelDebug = "debug"
+	// Default log level, informational
+	LevelInfo = "info"
+	// Warnings are messages about possible issues
+	LevelWarn = "warn"
+	// Errors are messages about things we know are problems
+	LevelError = "error"
+
+	// DefaultFlushTimeout is the default amount of time mlog.Flush will wait
+	// before timing out.
+	DefaultFlushTimeout = time.Second * 5
+)
+
+var (
+	// disableZap is set when Zap should be disabled and Logr used instead.
+	// This is needed for unit testing as Zap has no shutdown capabilities
+	// and holds file handles until process exit. Currently unit test create
+	// many server instances, and thus many Zap log files.
+	// This flag will be removed when Zap is permanently replaced.
+	disableZap int32
+)
+
+// Type and function aliases from zap to limit the libraries scope into MM code
+type Field = zapcore.Field
+
+var Int64 = zap.Int64
+var Int32 = zap.Int32
+var Int = zap.Int
+var Uint32 = zap.Uint32
+var String = zap.String
+var Any = zap.Any
+var Err = zap.Error
+var NamedErr = zap.NamedError
+var Bool = zap.Bool
+var Duration = zap.Duration
+
+type LoggerIFace interface {
+	IsLevelEnabled(LogLevel) bool
+	Debug(string, ...Field)
+	Info(string, ...Field)
+	Warn(string, ...Field)
+	Error(string, ...Field)
+	Critical(string, ...Field)
+	Log(LogLevel, string, ...Field)
+	LogM([]LogLevel, string, ...Field)
+}
+
+type TargetInfo logr.TargetInfo
+
+type LoggerConfiguration struct {
+	EnableConsole bool
+	ConsoleJson   bool
+	EnableColor   bool
+	ConsoleLevel  string
+	EnableFile    bool
+	FileJson      bool
+	FileLevel     string
+	FileLocation  string
+}
+
+type Logger struct {
+	zap          *zap.Logger
+	consoleLevel zap.AtomicLevel
+	fileLevel    zap.AtomicLevel
+	logrLogger   *logr.Logger
+	mutex        *sync.RWMutex
+}
+
+func getZapLevel(level string) zapcore.Level {
+	switch level {
+	case LevelInfo:
+		return zapcore.InfoLevel
+	case LevelWarn:
+		return zapcore.WarnLevel
+	case LevelDebug:
+		return zapcore.DebugLevel
+	case LevelError:
+		return zapcore.ErrorLevel
+	default:
+		return zapcore.InfoLevel
+	}
+}
+
+func makeEncoder(json, color bool) zapcore.Encoder {
+	encoderConfig := zap.NewProductionEncoderConfig()
+	if json {
+		return zapcore.NewJSONEncoder(encoderConfig)
+	}
+
+	if color {
+		encoderConfig.EncodeLevel = zapcore.CapitalColorLevelEncoder
+	}
+	encoderConfig.EncodeTime = zapcore.ISO8601TimeEncoder
+	return zapcore.NewConsoleEncoder(encoderConfig)
+}
+
+func NewLogger(config *LoggerConfiguration) *Logger {
+	cores := []zapcore.Core{}
+	logger := &Logger{
+		consoleLevel: zap.NewAtomicLevelAt(getZapLevel(config.ConsoleLevel)),
+		fileLevel:    zap.NewAtomicLevelAt(getZapLevel(config.FileLevel)),
+		logrLogger:   newLogr(),
+		mutex:        &sync.RWMutex{},
+	}
+
+	if config.EnableConsole {
+		writer := zapcore.Lock(os.Stderr)
+		core := zapcore.NewCore(makeEncoder(config.ConsoleJson, config.EnableColor), writer, logger.consoleLevel)
+		cores = append(cores, core)
+	}
+
+	if config.EnableFile {
+		if atomic.LoadInt32(&disableZap) != 0 {
+			t := &LogTarget{
+				Type:         "file",
+				Format:       "json",
+				Levels:       mlogLevelToLogrLevels(config.FileLevel),
+				MaxQueueSize: DefaultMaxTargetQueue,
+				Options: []byte(fmt.Sprintf(`{"Filename":"%s", "MaxSizeMB":%d, "Compress":%t}`,
+					config.FileLocation, 100, true)),
+			}
+			if !config.FileJson {
+				t.Format = "plain"
+			}
+			if tgt, err := NewLogrTarget("mlogFile", t); err == nil {
+				logger.logrLogger.Logr().AddTarget(tgt)
+			} else {
+				Error("error creating mlogFile", Err(err))
+			}
+		} else {
+			writer := zapcore.AddSync(&lumberjack.Logger{
+				Filename: config.FileLocation,
+				MaxSize:  100,
+				Compress: true,
+			})
+
+			core := zapcore.NewCore(makeEncoder(config.FileJson, false), writer, logger.fileLevel)
+			cores = append(cores, core)
+		}
+	}
+
+	combinedCore := zapcore.NewTee(cores...)
+
+	logger.zap = zap.New(combinedCore,
+		zap.AddCaller(),
+	)
+	return logger
+}
+
+func (l *Logger) ChangeLevels(config *LoggerConfiguration) {
+	l.consoleLevel.SetLevel(getZapLevel(config.ConsoleLevel))
+	l.fileLevel.SetLevel(getZapLevel(config.FileLevel))
+}
+
+func (l *Logger) SetConsoleLevel(level string) {
+	l.consoleLevel.SetLevel(getZapLevel(level))
+}
+
+func (l *Logger) With(fields ...Field) *Logger {
+	newLogger := *l
+	newLogger.zap = newLogger.zap.With(fields...)
+	if newLogger.getLogger() != nil {
+		ll := newLogger.getLogger().WithFields(zapToLogr(fields))
+		newLogger.logrLogger = &ll
+	}
+	return &newLogger
+}
+
+func (l *Logger) StdLog(fields ...Field) *log.Logger {
+	return zap.NewStdLog(l.With(fields...).zap.WithOptions(getStdLogOption()))
+}
+
+// StdLogAt returns *log.Logger which writes to supplied zap logger at required level.
+func (l *Logger) StdLogAt(level string, fields ...Field) (*log.Logger, error) {
+	return zap.NewStdLogAt(l.With(fields...).zap.WithOptions(getStdLogOption()), getZapLevel(level))
+}
+
+// StdLogWriter returns a writer that can be hooked up to the output of a golang standard logger
+// anything written will be interpreted as log entries accordingly
+func (l *Logger) StdLogWriter() io.Writer {
+	newLogger := *l
+	newLogger.zap = newLogger.zap.WithOptions(zap.AddCallerSkip(4), getStdLogOption())
+	f := newLogger.Info
+	return &loggerWriter{f}
+}
+
+func (l *Logger) WithCallerSkip(skip int) *Logger {
+	newLogger := *l
+	newLogger.zap = newLogger.zap.WithOptions(zap.AddCallerSkip(skip))
+	return &newLogger
+}
+
+// Made for the plugin interface, wraps mlog in a simpler interface
+// at the cost of performance
+func (l *Logger) Sugar() *SugarLogger {
+	return &SugarLogger{
+		wrappedLogger: l,
+		zapSugar:      l.zap.Sugar(),
+	}
+}
+
+func (l *Logger) IsLevelEnabled(level LogLevel) bool {
+	return isLevelEnabled(l.getLogger(), logr.Level(level))
+}
+
+func (l *Logger) Debug(message string, fields ...Field) {
+	l.zap.Debug(message, fields...)
+	if isLevelEnabled(l.getLogger(), logr.Debug) {
+		l.getLogger().WithFields(zapToLogr(fields)).Debug(message)
+	}
+}
+
+func (l *Logger) Info(message string, fields ...Field) {
+	l.zap.Info(message, fields...)
+	if isLevelEnabled(l.getLogger(), logr.Info) {
+		l.getLogger().WithFields(zapToLogr(fields)).Info(message)
+	}
+}
+
+func (l *Logger) Warn(message string, fields ...Field) {
+	l.zap.Warn(message, fields...)
+	if isLevelEnabled(l.getLogger(), logr.Warn) {
+		l.getLogger().WithFields(zapToLogr(fields)).Warn(message)
+	}
+}
+
+func (l *Logger) Error(message string, fields ...Field) {
+	l.zap.Error(message, fields...)
+	if isLevelEnabled(l.getLogger(), logr.Error) {
+		l.getLogger().WithFields(zapToLogr(fields)).Error(message)
+	}
+}
+
+func (l *Logger) Critical(message string, fields ...Field) {
+	l.zap.Error(message, fields...)
+	if isLevelEnabled(l.getLogger(), logr.Error) {
+		l.getLogger().WithFields(zapToLogr(fields)).Error(message)
+	}
+}
+
+func (l *Logger) Log(level LogLevel, message string, fields ...Field) {
+	l.getLogger().WithFields(zapToLogr(fields)).Log(logr.Level(level), message)
+}
+
+func (l *Logger) LogM(levels []LogLevel, message string, fields ...Field) {
+	var logger *logr.Logger
+	for _, lvl := range levels {
+		if isLevelEnabled(l.getLogger(), logr.Level(lvl)) {
+			// don't create logger with fields unless at least one level is active.
+			if logger == nil {
+				l := l.getLogger().WithFields(zapToLogr(fields))
+				logger = &l
+			}
+			logger.Log(logr.Level(lvl), message)
+		}
+	}
+}
+
+func (l *Logger) Flush(cxt context.Context) error {
+	return l.getLogger().Logr().FlushWithTimeout(cxt)
+}
+
+// ShutdownAdvancedLogging stops the logger from accepting new log records and tries to
+// flush queues within the context timeout. Once complete all targets are shutdown
+// and any resources released.
+func (l *Logger) ShutdownAdvancedLogging(cxt context.Context) error {
+	err := l.getLogger().Logr().ShutdownWithTimeout(cxt)
+	l.setLogger(newLogr())
+	return err
+}
+
+// ConfigAdvancedLoggingConfig (re)configures advanced logging based on the
+// specified log targets. This is the easiest way to get the advanced logger
+// configured via a config source such as file.
+func (l *Logger) ConfigAdvancedLogging(targets LogTargetCfg) error {
+	if err := l.ShutdownAdvancedLogging(context.Background()); err != nil {
+		Error("error shutting down previous logger", Err(err))
+	}
+
+	err := logrAddTargets(l.getLogger(), targets)
+	return err
+}
+
+// AddTarget adds one or more logr.Target to the advanced logger. This is the preferred method
+// to add custom targets or provide configuration that cannot be expressed via a
+// config source.
+func (l *Logger) AddTarget(targets ...logr.Target) error {
+	return l.getLogger().Logr().AddTarget(targets...)
+}
+
+// RemoveTargets selectively removes targets that were previously added to this logger instance
+// using the passed in filter function. The filter function should return true to remove the target
+// and false to keep it.
+func (l *Logger) RemoveTargets(ctx context.Context, f func(ti TargetInfo) bool) error {
+	// Use locally defined TargetInfo type so we don't spread Logr dependencies.
+	fc := func(tic logr.TargetInfo) bool {
+		return f(TargetInfo(tic))
+	}
+	return l.getLogger().Logr().RemoveTargets(ctx, fc)
+}
+
+// EnableMetrics enables metrics collection by supplying a MetricsCollector.
+// The MetricsCollector provides counters and gauges that are updated by log targets.
+func (l *Logger) EnableMetrics(collector logr.MetricsCollector) error {
+	return l.getLogger().Logr().SetMetricsCollector(collector)
+}
+
+// getLogger is a concurrent safe getter of the logr logger
+func (l *Logger) getLogger() *logr.Logger {
+	defer l.mutex.RUnlock()
+	l.mutex.RLock()
+	return l.logrLogger
+}
+
+// setLogger is a concurrent safe setter of the logr logger
+func (l *Logger) setLogger(logger *logr.Logger) {
+	defer l.mutex.Unlock()
+	l.mutex.Lock()
+	l.logrLogger = logger
+}
+
+// DisableZap is called to disable Zap, and Logr will be used instead. Any Logger
+// instances created after this call will only use Logr.
+//
+// This is needed for unit testing as Zap has no shutdown capabilities
+// and holds file handles until process exit. Currently unit tests create
+// many server instances, and thus many Zap log file handles.
+//
+// This method will be removed when Zap is permanently replaced.
+func DisableZap() {
+	atomic.StoreInt32(&disableZap, 1)
+}
+
+// EnableZap re-enables Zap such that any Logger instances created after this
+// call will allow Zap targets.
+func EnableZap() {
+	atomic.StoreInt32(&disableZap, 0)
+}

vendor/github.com/mattermost/mattermost-server/v5/shared/mlog/logr.go

@@ -0,0 +1,244 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package mlog
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"os"
+
+	"github.com/hashicorp/go-multierror"
+	"github.com/mattermost/logr"
+	logrFmt "github.com/mattermost/logr/format"
+	"github.com/mattermost/logr/target"
+	"go.uber.org/zap/zapcore"
+)
+
+const (
+	DefaultMaxTargetQueue = 1000
+	DefaultSysLogPort     = 514
+)
+
+type LogLevel struct {
+	ID         logr.LevelID
+	Name       string
+	Stacktrace bool
+}
+
+type LogTarget struct {
+	Type         string // one of "console", "file", "tcp", "syslog", "none".
+	Format       string // one of "json", "plain"
+	Levels       []LogLevel
+	Options      json.RawMessage
+	MaxQueueSize int
+}
+
+type LogTargetCfg map[string]*LogTarget
+type LogrCleanup func() error
+
+func newLogr() *logr.Logger {
+	lgr := &logr.Logr{}
+	lgr.OnExit = func(int) {}
+	lgr.OnPanic = func(interface{}) {}
+	lgr.OnLoggerError = onLoggerError
+	lgr.OnQueueFull = onQueueFull
+	lgr.OnTargetQueueFull = onTargetQueueFull
+
+	logger := lgr.NewLogger()
+	return &logger
+}
+
+func logrAddTargets(logger *logr.Logger, targets LogTargetCfg) error {
+	lgr := logger.Logr()
+	var errs error
+	for name, t := range targets {
+		target, err := NewLogrTarget(name, t)
+		if err != nil {
+			errs = multierror.Append(err)
+			continue
+		}
+		if target != nil {
+			target.SetName(name)
+			lgr.AddTarget(target)
+		}
+	}
+	return errs
+}
+
+// NewLogrTarget creates a `logr.Target` based on a target config.
+// Can be used when parsing custom config files, or when programmatically adding
+// built-in targets. Use `mlog.AddTarget` to add custom targets.
+func NewLogrTarget(name string, t *LogTarget) (logr.Target, error) {
+	formatter, err := newFormatter(name, t.Format)
+	if err != nil {
+		return nil, err
+	}
+	filter := newFilter(t.Levels)
+
+	if t.MaxQueueSize == 0 {
+		t.MaxQueueSize = DefaultMaxTargetQueue
+	}
+
+	switch t.Type {
+	case "console":
+		return newConsoleTarget(name, t, filter, formatter)
+	case "file":
+		return newFileTarget(name, t, filter, formatter)
+	case "syslog":
+		return newSyslogTarget(name, t, filter, formatter)
+	case "tcp":
+		return newTCPTarget(name, t, filter, formatter)
+	case "none":
+		return nil, nil
+	}
+	return nil, fmt.Errorf("invalid type '%s' for target %s", t.Type, name)
+}
+
+func newFilter(levels []LogLevel) logr.Filter {
+	filter := &logr.CustomFilter{}
+	for _, lvl := range levels {
+		filter.Add(logr.Level(lvl))
+	}
+	return filter
+}
+
+func newFormatter(name string, format string) (logr.Formatter, error) {
+	switch format {
+	case "json", "":
+		return &logrFmt.JSON{}, nil
+	case "plain":
+		return &logrFmt.Plain{Delim: " | "}, nil
+	default:
+		return nil, fmt.Errorf("invalid format '%s' for target %s", format, name)
+	}
+}
+
+func newConsoleTarget(name string, t *LogTarget, filter logr.Filter, formatter logr.Formatter) (logr.Target, error) {
+	type consoleOptions struct {
+		Out string `json:"Out"`
+	}
+	options := &consoleOptions{}
+	if err := json.Unmarshal(t.Options, options); err != nil {
+		return nil, err
+	}
+
+	var w io.Writer
+	switch options.Out {
+	case "stdout", "":
+		w = os.Stdout
+	case "stderr":
+		w = os.Stderr
+	default:
+		return nil, fmt.Errorf("invalid out '%s' for target %s", options.Out, name)
+	}
+
+	newTarget := target.NewWriterTarget(filter, formatter, w, t.MaxQueueSize)
+	return newTarget, nil
+}
+
+func newFileTarget(name string, t *LogTarget, filter logr.Filter, formatter logr.Formatter) (logr.Target, error) {
+	type fileOptions struct {
+		Filename   string `json:"Filename"`
+		MaxSize    int    `json:"MaxSizeMB"`
+		MaxAge     int    `json:"MaxAgeDays"`
+		MaxBackups int    `json:"MaxBackups"`
+		Compress   bool   `json:"Compress"`
+	}
+	options := &fileOptions{}
+	if err := json.Unmarshal(t.Options, options); err != nil {
+		return nil, err
+	}
+	return newFileTargetWithOpts(name, t, target.FileOptions(*options), filter, formatter)
+}
+
+func newFileTargetWithOpts(name string, t *LogTarget, opts target.FileOptions, filter logr.Filter, formatter logr.Formatter) (logr.Target, error) {
+	if opts.Filename == "" {
+		return nil, fmt.Errorf("missing 'Filename' option for target %s", name)
+	}
+	if err := checkFileWritable(opts.Filename); err != nil {
+		return nil, fmt.Errorf("error writing to 'Filename' for target %s: %w", name, err)
+	}
+
+	newTarget := target.NewFileTarget(filter, formatter, opts, t.MaxQueueSize)
+	return newTarget, nil
+}
+
+func newSyslogTarget(name string, t *LogTarget, filter logr.Filter, formatter logr.Formatter) (logr.Target, error) {
+	options := &SyslogParams{}
+	if err := json.Unmarshal(t.Options, options); err != nil {
+		return nil, err
+	}
+
+	if options.IP == "" {
+		return nil, fmt.Errorf("missing 'IP' option for target %s", name)
+	}
+	if options.Port == 0 {
+		options.Port = DefaultSysLogPort
+	}
+	return NewSyslogTarget(filter, formatter, options, t.MaxQueueSize)
+}
+
+func newTCPTarget(name string, t *LogTarget, filter logr.Filter, formatter logr.Formatter) (logr.Target, error) {
+	options := &TcpParams{}
+	if err := json.Unmarshal(t.Options, options); err != nil {
+		return nil, err
+	}
+
+	if options.IP == "" {
+		return nil, fmt.Errorf("missing 'IP' option for target %s", name)
+	}
+	if options.Port == 0 {
+		return nil, fmt.Errorf("missing 'Port' option for target %s", name)
+	}
+	return NewTcpTarget(filter, formatter, options, t.MaxQueueSize)
+}
+
+func checkFileWritable(filename string) error {
+	// try opening/creating the file for writing
+	file, err := os.OpenFile(filename, os.O_RDWR|os.O_APPEND|os.O_CREATE, 0600)
+	if err != nil {
+		return err
+	}
+	file.Close()
+	return nil
+}
+
+func isLevelEnabled(logger *logr.Logger, level logr.Level) bool {
+	if logger == nil || logger.Logr() == nil {
+		return false
+	}
+
+	status := logger.Logr().IsLevelEnabled(level)
+	return status.Enabled
+}
+
+// zapToLogr converts Zap fields to Logr fields.
+// This will not be needed once Logr is used for all logging.
+func zapToLogr(zapFields []Field) logr.Fields {
+	encoder := zapcore.NewMapObjectEncoder()
+	for _, zapField := range zapFields {
+		zapField.AddTo(encoder)
+	}
+	return logr.Fields(encoder.Fields)
+}
+
+// mlogLevelToLogrLevel converts a mlog logger level to
+// an array of discrete Logr levels.
+func mlogLevelToLogrLevels(level string) []LogLevel {
+	levels := make([]LogLevel, 0)
+	levels = append(levels, LvlError, LvlPanic, LvlFatal, LvlStdLog)
+
+	switch level {
+	case LevelDebug:
+		levels = append(levels, LvlDebug)
+		fallthrough
+	case LevelInfo:
+		levels = append(levels, LvlInfo)
+		fallthrough
+	case LevelWarn:
+		levels = append(levels, LvlWarn)
+	}
+	return levels
+}

vendor/github.com/mattermost/mattermost-server/v5/shared/mlog/stdlog.go

@@ -0,0 +1,87 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package mlog
+
+import (
+	"bytes"
+	"strings"
+
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+)
+
+// Implementation of zapcore.Core to interpret log messages from a standard logger
+// and translate the levels to zapcore levels.
+type stdLogLevelInterpreterCore struct {
+	wrappedCore zapcore.Core
+}
+
+func stdLogInterpretZapEntry(entry zapcore.Entry) zapcore.Entry {
+	message := entry.Message
+	if strings.Index(message, "[DEBUG]") == 0 {
+		entry.Level = zapcore.DebugLevel
+		entry.Message = message[7:]
+	} else if strings.Index(message, "[DEBG]") == 0 {
+		entry.Level = zapcore.DebugLevel
+		entry.Message = message[6:]
+	} else if strings.Index(message, "[WARN]") == 0 {
+		entry.Level = zapcore.WarnLevel
+		entry.Message = message[6:]
+	} else if strings.Index(message, "[ERROR]") == 0 {
+		entry.Level = zapcore.ErrorLevel
+		entry.Message = message[7:]
+	} else if strings.Index(message, "[EROR]") == 0 {
+		entry.Level = zapcore.ErrorLevel
+		entry.Message = message[6:]
+	} else if strings.Index(message, "[ERR]") == 0 {
+		entry.Level = zapcore.ErrorLevel
+		entry.Message = message[5:]
+	} else if strings.Index(message, "[INFO]") == 0 {
+		entry.Level = zapcore.InfoLevel
+		entry.Message = message[6:]
+	}
+	return entry
+}
+
+func (s *stdLogLevelInterpreterCore) Enabled(lvl zapcore.Level) bool {
+	return s.wrappedCore.Enabled(lvl)
+}
+
+func (s *stdLogLevelInterpreterCore) With(fields []zapcore.Field) zapcore.Core {
+	return s.wrappedCore.With(fields)
+}
+
+func (s *stdLogLevelInterpreterCore) Check(entry zapcore.Entry, checkedEntry *zapcore.CheckedEntry) *zapcore.CheckedEntry {
+	entry = stdLogInterpretZapEntry(entry)
+	return s.wrappedCore.Check(entry, checkedEntry)
+}
+
+func (s *stdLogLevelInterpreterCore) Write(entry zapcore.Entry, fields []zapcore.Field) error {
+	entry = stdLogInterpretZapEntry(entry)
+	return s.wrappedCore.Write(entry, fields)
+}
+
+func (s *stdLogLevelInterpreterCore) Sync() error {
+	return s.wrappedCore.Sync()
+}
+
+func getStdLogOption() zap.Option {
+	return zap.WrapCore(
+		func(core zapcore.Core) zapcore.Core {
+			return &stdLogLevelInterpreterCore{core}
+		},
+	)
+}
+
+type loggerWriter struct {
+	logFunc func(msg string, fields ...Field)
+}
+
+func (l *loggerWriter) Write(p []byte) (int, error) {
+	trimmed := string(bytes.TrimSpace(p))
+	for _, line := range strings.Split(trimmed, "\n") {
+		l.logFunc(line)
+	}
+	return len(p), nil
+}

vendor/github.com/mattermost/mattermost-server/v5/shared/mlog/sugar.go

@@ -0,0 +1,30 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package mlog
+
+import (
+	"go.uber.org/zap"
+)
+
+// Made for the plugin interface, use the regular logger for other uses
+type SugarLogger struct {
+	wrappedLogger *Logger
+	zapSugar      *zap.SugaredLogger
+}
+
+func (l *SugarLogger) Debug(msg string, keyValuePairs ...interface{}) {
+	l.zapSugar.Debugw(msg, keyValuePairs...)
+}
+
+func (l *SugarLogger) Info(msg string, keyValuePairs ...interface{}) {
+	l.zapSugar.Infow(msg, keyValuePairs...)
+}
+
+func (l *SugarLogger) Error(msg string, keyValuePairs ...interface{}) {
+	l.zapSugar.Errorw(msg, keyValuePairs...)
+}
+
+func (l *SugarLogger) Warn(msg string, keyValuePairs ...interface{}) {
+	l.zapSugar.Warnw(msg, keyValuePairs...)
+}

vendor/github.com/mattermost/mattermost-server/v5/shared/mlog/syslog.go

@@ -0,0 +1,142 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package mlog
+
+import (
+	"context"
+	"crypto/tls"
+	"crypto/x509"
+	"encoding/base64"
+	"errors"
+	"fmt"
+	"io/ioutil"
+
+	"github.com/mattermost/logr"
+	"github.com/wiggin77/merror"
+	syslog "github.com/wiggin77/srslog"
+)
+
+// Syslog outputs log records to local or remote syslog.
+type Syslog struct {
+	logr.Basic
+	w *syslog.Writer
+}
+
+// SyslogParams provides parameters for dialing a syslog daemon.
+type SyslogParams struct {
+	IP       string `json:"IP"`
+	Port     int    `json:"Port"`
+	Tag      string `json:"Tag"`
+	TLS      bool   `json:"TLS"`
+	Cert     string `json:"Cert"`
+	Insecure bool   `json:"Insecure"`
+}
+
+// NewSyslogTarget creates a target capable of outputting log records to remote or local syslog, with or without TLS.
+func NewSyslogTarget(filter logr.Filter, formatter logr.Formatter, params *SyslogParams, maxQueue int) (*Syslog, error) {
+	network := "tcp"
+	var config *tls.Config
+
+	if params.TLS {
+		network = "tcp+tls"
+		config = &tls.Config{InsecureSkipVerify: params.Insecure}
+		if params.Cert != "" {
+			pool, err := getCertPool(params.Cert)
+			if err != nil {
+				return nil, err
+			}
+			config.RootCAs = pool
+		}
+	}
+	raddr := fmt.Sprintf("%s:%d", params.IP, params.Port)
+
+	writer, err := syslog.DialWithTLSConfig(network, raddr, syslog.LOG_INFO, params.Tag, config)
+	if err != nil {
+		return nil, err
+	}
+
+	s := &Syslog{w: writer}
+	s.Basic.Start(s, s, filter, formatter, maxQueue)
+
+	return s, nil
+}
+
+// Shutdown stops processing log records after making best effort to flush queue.
+func (s *Syslog) Shutdown(ctx context.Context) error {
+	errs := merror.New()
+
+	err := s.Basic.Shutdown(ctx)
+	errs.Append(err)
+
+	err = s.w.Close()
+	errs.Append(err)
+
+	return errs.ErrorOrNil()
+}
+
+// getCertPool returns a x509.CertPool containing the cert(s)
+// from `cert`, which can be a path to a .pem or .crt file,
+// or a base64 encoded cert.
+func getCertPool(cert string) (*x509.CertPool, error) {
+	if cert == "" {
+		return nil, errors.New("no cert provided")
+	}
+
+	// first treat as a file and try to read.
+	serverCert, err := ioutil.ReadFile(cert)
+	if err != nil {
+		// maybe it's a base64 encoded cert
+		serverCert, err = base64.StdEncoding.DecodeString(cert)
+		if err != nil {
+			return nil, errors.New("cert cannot be read")
+		}
+	}
+
+	pool := x509.NewCertPool()
+	if ok := pool.AppendCertsFromPEM(serverCert); ok {
+		return pool, nil
+	}
+	return nil, errors.New("cannot parse cert")
+}
+
+// Write converts the log record to bytes, via the Formatter,
+// and outputs to syslog.
+func (s *Syslog) Write(rec *logr.LogRec) error {
+	_, stacktrace := s.IsLevelEnabled(rec.Level())
+
+	buf := rec.Logger().Logr().BorrowBuffer()
+	defer rec.Logger().Logr().ReleaseBuffer(buf)
+
+	buf, err := s.Formatter().Format(rec, stacktrace, buf)
+	if err != nil {
+		return err
+	}
+	txt := buf.String()
+
+	switch rec.Level() {
+	case logr.Panic, logr.Fatal:
+		err = s.w.Crit(txt)
+	case logr.Error:
+		err = s.w.Err(txt)
+	case logr.Warn:
+		err = s.w.Warning(txt)
+	case logr.Debug, logr.Trace:
+		err = s.w.Debug(txt)
+	default:
+		// logr.Info plus all custom levels.
+		err = s.w.Info(txt)
+	}
+
+	if err != nil {
+		reporter := rec.Logger().Logr().ReportError
+		reporter(fmt.Errorf("syslog write fail: %w", err))
+		// syslog writer will try to reconnect.
+	}
+	return err
+}
+
+// String returns a string representation of this target.
+func (s *Syslog) String() string {
+	return "SyslogTarget"
+}

vendor/github.com/mattermost/mattermost-server/v5/shared/mlog/tcp.go

@@ -0,0 +1,273 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package mlog
+
+import (
+	"context"
+	"crypto/tls"
+	"errors"
+	"fmt"
+	"net"
+	_ "net/http/pprof"
+	"sync"
+	"time"
+
+	"github.com/hashicorp/go-multierror"
+	"github.com/mattermost/logr"
+)
+
+const (
+	DialTimeoutSecs             = 30
+	WriteTimeoutSecs            = 30
+	RetryBackoffMillis    int64 = 100
+	MaxRetryBackoffMillis int64 = 30 * 1000 // 30 seconds
+)
+
+// Tcp outputs log records to raw socket server.
+type Tcp struct {
+	logr.Basic
+
+	params *TcpParams
+	addy   string
+
+	mutex    sync.Mutex
+	conn     net.Conn
+	monitor  chan struct{}
+	shutdown chan struct{}
+}
+
+// TcpParams provides parameters for dialing a socket server.
+type TcpParams struct {
+	IP       string `json:"IP"`
+	Port     int    `json:"Port"`
+	TLS      bool   `json:"TLS"`
+	Cert     string `json:"Cert"`
+	Insecure bool   `json:"Insecure"`
+}
+
+// NewTcpTarget creates a target capable of outputting log records to a raw socket, with or without TLS.
+func NewTcpTarget(filter logr.Filter, formatter logr.Formatter, params *TcpParams, maxQueue int) (*Tcp, error) {
+	tcp := &Tcp{
+		params:   params,
+		addy:     fmt.Sprintf("%s:%d", params.IP, params.Port),
+		monitor:  make(chan struct{}),
+		shutdown: make(chan struct{}),
+	}
+	tcp.Basic.Start(tcp, tcp, filter, formatter, maxQueue)
+
+	return tcp, nil
+}
+
+// getConn provides a net.Conn.  If a connection already exists, it is returned immediately,
+// otherwise this method blocks until a new connection is created, timeout or shutdown.
+func (tcp *Tcp) getConn() (net.Conn, error) {
+	tcp.mutex.Lock()
+	defer tcp.mutex.Unlock()
+
+	Log(LvlTcpLogTarget, "getConn enter", String("addy", tcp.addy))
+	defer Log(LvlTcpLogTarget, "getConn exit", String("addy", tcp.addy))
+
+	if tcp.conn != nil {
+		Log(LvlTcpLogTarget, "reusing existing conn", String("addy", tcp.addy)) // use "With" once Zap is removed
+		return tcp.conn, nil
+	}
+
+	type result struct {
+		conn net.Conn
+		err  error
+	}
+
+	connChan := make(chan result)
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second*DialTimeoutSecs)
+	defer cancel()
+
+	go func(ctx context.Context, ch chan result) {
+		Log(LvlTcpLogTarget, "dailing", String("addy", tcp.addy))
+		conn, err := tcp.dial(ctx)
+		if err == nil {
+			tcp.conn = conn
+			tcp.monitor = make(chan struct{})
+			go monitor(tcp.conn, tcp.monitor, Log)
+		}
+		ch <- result{conn: conn, err: err}
+	}(ctx, connChan)
+
+	select {
+	case <-tcp.shutdown:
+		return nil, errors.New("shutdown")
+	case res := <-connChan:
+		return res.conn, res.err
+	}
+}
+
+// dial connects to a TCP socket, and optionally performs a TLS handshake.
+// A non-nil context must be provided which can cancel the dial.
+func (tcp *Tcp) dial(ctx context.Context) (net.Conn, error) {
+	var dialer net.Dialer
+	dialer.Timeout = time.Second * DialTimeoutSecs
+	conn, err := dialer.DialContext(ctx, "tcp", fmt.Sprintf("%s:%d", tcp.params.IP, tcp.params.Port))
+	if err != nil {
+		return nil, err
+	}
+
+	if !tcp.params.TLS {
+		return conn, nil
+	}
+
+	Log(LvlTcpLogTarget, "TLS handshake", String("addy", tcp.addy))
+
+	tlsconfig := &tls.Config{
+		ServerName:         tcp.params.IP,
+		InsecureSkipVerify: tcp.params.Insecure,
+	}
+	if tcp.params.Cert != "" {
+		pool, err := getCertPool(tcp.params.Cert)
+		if err != nil {
+			return nil, err
+		}
+		tlsconfig.RootCAs = pool
+	}
+
+	tlsConn := tls.Client(conn, tlsconfig)
+	if err := tlsConn.Handshake(); err != nil {
+		return nil, err
+	}
+	return tlsConn, nil
+}
+
+func (tcp *Tcp) close() error {
+	tcp.mutex.Lock()
+	defer tcp.mutex.Unlock()
+
+	var err error
+	if tcp.conn != nil {
+		Log(LvlTcpLogTarget, "closing connection", String("addy", tcp.addy))
+		close(tcp.monitor)
+		err = tcp.conn.Close()
+		tcp.conn = nil
+	}
+	return err
+}
+
+// Shutdown stops processing log records after making best effort to flush queue.
+func (tcp *Tcp) Shutdown(ctx context.Context) error {
+	errs := &multierror.Error{}
+
+	Log(LvlTcpLogTarget, "shutting down", String("addy", tcp.addy))
+
+	if err := tcp.Basic.Shutdown(ctx); err != nil {
+		errs = multierror.Append(errs, err)
+	}
+
+	if err := tcp.close(); err != nil {
+		errs = multierror.Append(errs, err)
+	}
+
+	close(tcp.shutdown)
+	return errs.ErrorOrNil()
+}
+
+// Write converts the log record to bytes, via the Formatter, and outputs to the socket.
+// Called by dedicated target goroutine and will block until success or shutdown.
+func (tcp *Tcp) Write(rec *logr.LogRec) error {
+	_, stacktrace := tcp.IsLevelEnabled(rec.Level())
+
+	buf := rec.Logger().Logr().BorrowBuffer()
+	defer rec.Logger().Logr().ReleaseBuffer(buf)
+
+	buf, err := tcp.Formatter().Format(rec, stacktrace, buf)
+	if err != nil {
+		return err
+	}
+
+	try := 1
+	backoff := RetryBackoffMillis
+	for {
+		select {
+		case <-tcp.shutdown:
+			return err
+		default:
+		}
+
+		conn, err := tcp.getConn()
+		if err != nil {
+			Log(LvlTcpLogTarget, "failed getting connection", String("addy", tcp.addy), Err(err))
+			reporter := rec.Logger().Logr().ReportError
+			reporter(fmt.Errorf("log target %s connection error: %w", tcp.String(), err))
+			backoff = tcp.sleep(backoff)
+			continue
+		}
+
+		conn.SetWriteDeadline(time.Now().Add(time.Second * WriteTimeoutSecs))
+		_, err = buf.WriteTo(conn)
+		if err == nil {
+			return nil
+		}
+
+		Log(LvlTcpLogTarget, "write error", String("addy", tcp.addy), Err(err))
+		reporter := rec.Logger().Logr().ReportError
+		reporter(fmt.Errorf("log target %s write error: %w", tcp.String(), err))
+
+		_ = tcp.close()
+
+		backoff = tcp.sleep(backoff)
+		try++
+		Log(LvlTcpLogTarget, "retrying write", String("addy", tcp.addy), Int("try", try))
+	}
+}
+
+// monitor continuously tries to read from the connection to detect socket close.
+// This is needed because TCP target uses a write only socket and Linux systems
+// take a long time to detect a loss of connectivity on a socket when only writing;
+// the writes simply fail without an error returned.
+func monitor(conn net.Conn, done <-chan struct{}, logFunc LogFuncCustom) {
+	addy := conn.RemoteAddr().String()
+	defer logFunc(LvlTcpLogTarget, "monitor exiting", String("addy", addy))
+
+	buf := make([]byte, 1)
+	for {
+		logFunc(LvlTcpLogTarget, "monitor loop", String("addy", addy))
+
+		select {
+		case <-done:
+			return
+		case <-time.After(1 * time.Second):
+		}
+
+		err := conn.SetReadDeadline(time.Now().Add(time.Second * 30))
+		if err != nil {
+			continue
+		}
+
+		_, err = conn.Read(buf)
+
+		if errt, ok := err.(net.Error); ok && errt.Timeout() {
+			// read timeout is expected, keep looping.
+			continue
+		}
+
+		// Any other error closes the connection, forcing a reconnect.
+		logFunc(LvlTcpLogTarget, "monitor closing connection", Err(err))
+		conn.Close()
+		return
+	}
+}
+
+// String returns a string representation of this target.
+func (tcp *Tcp) String() string {
+	return fmt.Sprintf("TcpTarget[%s:%d]", tcp.params.IP, tcp.params.Port)
+}
+
+func (tcp *Tcp) sleep(backoff int64) int64 {
+	select {
+	case <-tcp.shutdown:
+	case <-time.After(time.Millisecond * time.Duration(backoff)):
+	}
+
+	nextBackoff := backoff + (backoff >> 1)
+	if nextBackoff > MaxRetryBackoffMillis {
+		nextBackoff = MaxRetryBackoffMillis
+	}
+	return nextBackoff
+}

vendor/github.com/mattermost/mattermost-server/v5/shared/mlog/test-tls-client-cert.pem

@@ -0,0 +1,43 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE----- 
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----

vendor/github.com/mattermost/mattermost-server/v5/shared/mlog/testing.go

@@ -0,0 +1,46 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package mlog
+
+import (
+	"io"
+	"strings"
+	"sync"
+	"testing"
+
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+)
+
+// testingWriter is an io.Writer that writes through t.Log
+type testingWriter struct {
+	tb testing.TB
+}
+
+func (tw *testingWriter) Write(b []byte) (int, error) {
+	tw.tb.Log(strings.TrimSpace(string(b)))
+	return len(b), nil
+}
+
+// NewTestingLogger creates a Logger that proxies logs through a testing interface.
+// This allows tests that spin up App instances to avoid spewing logs unless the test fails or -verbose is specified.
+func NewTestingLogger(tb testing.TB, writer io.Writer) *Logger {
+	logWriter := &testingWriter{tb}
+	multiWriter := io.MultiWriter(logWriter, writer)
+	logWriterSync := zapcore.AddSync(multiWriter)
+
+	testingLogger := &Logger{
+		consoleLevel: zap.NewAtomicLevelAt(getZapLevel("debug")),
+		fileLevel:    zap.NewAtomicLevelAt(getZapLevel("info")),
+		logrLogger:   newLogr(),
+		mutex:        &sync.RWMutex{},
+	}
+
+	logWriterCore := zapcore.NewCore(makeEncoder(true, false), zapcore.Lock(logWriterSync), testingLogger.consoleLevel)
+
+	testingLogger.zap = zap.New(logWriterCore,
+		zap.AddCaller(),
+	)
+	return testingLogger
+}