Update mattermost library (#2152)

* Update mattermost library

* Fix linting

vendor/github.com/hashicorp/go-hclog/stdlog.go

@@ -0,0 +1,113 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MIT
+
+package hclog
+
+import (
+	"bytes"
+	"log"
+	"regexp"
+	"strings"
+)
+
+// Regex to ignore characters commonly found in timestamp formats from the
+// beginning of inputs.
+var logTimestampRegexp = regexp.MustCompile(`^[\d\s\:\/\.\+-TZ]*`)
+
+// Provides a io.Writer to shim the data out of *log.Logger
+// and back into our Logger. This is basically the only way to
+// build upon *log.Logger.
+type stdlogAdapter struct {
+	log                      Logger
+	inferLevels              bool
+	inferLevelsWithTimestamp bool
+	forceLevel               Level
+}
+
+// Take the data, infer the levels if configured, and send it through
+// a regular Logger.
+func (s *stdlogAdapter) Write(data []byte) (int, error) {
+	str := string(bytes.TrimRight(data, " \t\n"))
+
+	if s.forceLevel != NoLevel {
+		// Use pickLevel to strip log levels included in the line since we are
+		// forcing the level
+		_, str := s.pickLevel(str)
+
+		// Log at the forced level
+		s.dispatch(str, s.forceLevel)
+	} else if s.inferLevels {
+		if s.inferLevelsWithTimestamp {
+			str = s.trimTimestamp(str)
+		}
+
+		level, str := s.pickLevel(str)
+		s.dispatch(str, level)
+	} else {
+		s.log.Info(str)
+	}
+
+	return len(data), nil
+}
+
+func (s *stdlogAdapter) dispatch(str string, level Level) {
+	switch level {
+	case Trace:
+		s.log.Trace(str)
+	case Debug:
+		s.log.Debug(str)
+	case Info:
+		s.log.Info(str)
+	case Warn:
+		s.log.Warn(str)
+	case Error:
+		s.log.Error(str)
+	default:
+		s.log.Info(str)
+	}
+}
+
+// Detect, based on conventions, what log level this is.
+func (s *stdlogAdapter) pickLevel(str string) (Level, string) {
+	switch {
+	case strings.HasPrefix(str, "[DEBUG]"):
+		return Debug, strings.TrimSpace(str[7:])
+	case strings.HasPrefix(str, "[TRACE]"):
+		return Trace, strings.TrimSpace(str[7:])
+	case strings.HasPrefix(str, "[INFO]"):
+		return Info, strings.TrimSpace(str[6:])
+	case strings.HasPrefix(str, "[WARN]"):
+		return Warn, strings.TrimSpace(str[6:])
+	case strings.HasPrefix(str, "[ERROR]"):
+		return Error, strings.TrimSpace(str[7:])
+	case strings.HasPrefix(str, "[ERR]"):
+		return Error, strings.TrimSpace(str[5:])
+	default:
+		return Info, str
+	}
+}
+
+func (s *stdlogAdapter) trimTimestamp(str string) string {
+	idx := logTimestampRegexp.FindStringIndex(str)
+	return str[idx[1]:]
+}
+
+type logWriter struct {
+	l *log.Logger
+}
+
+func (l *logWriter) Write(b []byte) (int, error) {
+	l.l.Println(string(bytes.TrimRight(b, " \n\t")))
+	return len(b), nil
+}
+
+// Takes a standard library logger and returns a Logger that will write to it
+func FromStandardLogger(l *log.Logger, opts *LoggerOptions) Logger {
+	var dl LoggerOptions = *opts
+
+	// Use the time format that log.Logger uses
+	dl.DisableTime = true
+	dl.Output = &logWriter{l}
+
+	return New(&dl)
+}