Use metadata from config file

src/config/config.go

@@ -19,7 +19,7 @@ type NodeConfig struct {
 	SessionFirewall             SessionFirewall        `comment:"The session firewall controls who can send/receive network traffic\nto/from. This is useful if you want to protect this node without\nresorting to using a real firewall. This does not affect traffic\nbeing routed via this node to somewhere else. Rules are prioritised as\nfollows: blacklist, whitelist, always allow outgoing, direct, remote."`
 	TunnelRouting               TunnelRouting          `comment:"Allow tunneling non-Yggdrasil traffic over Yggdrasil. This effectively\nallows you to use Yggdrasil to route to, or to bridge other networks,\nsimilar to a VPN tunnel. Tunnelling works between any two nodes and\ndoes not require them to be directly peered."`
 	SwitchOptions               SwitchOptions          `comment:"Advanced options for tuning the switch. Normally you will not need\nto edit these options."`
-	Metadata                    interface{}         `comment:"Optional node metadata. Entirely optional but visible to all\npeers and nodes with open sessions."`
+	Metadata                    map[string]interface{} `comment:"Optional node metadata. This must be a { \"key\": \"value\", ... } map\nor set as null. This is entirely optional but, if set, is visible\nto the whole network on request."`
 	//Net                         NetConfig `comment:"Extended options for connecting to peers over other networks."`
 }
 

src/yggdrasil/core.go

@@ -2,13 +2,11 @@ package yggdrasil
 
 import (
 	"encoding/hex"
-	"encoding/json"
 	"fmt"
 	"io/ioutil"
 	"log"
 	"net"
 	"regexp"
-	"runtime"
 
 	"github.com/yggdrasil-network/yggdrasil-go/src/config"
 	"github.com/yggdrasil-network/yggdrasil-go/src/defaults"
@@ -126,15 +124,7 @@ func (c *Core) Start(nc *config.NodeConfig, log *log.Logger) error {
 	c.admin.init(c, nc.AdminListen)
 
 	c.metadata.init(c)
-	m := map[string]string{
-		"buildname":     GetBuildName(),
-		"buildversion":  GetBuildVersion(),
-		"buildplatform": runtime.GOOS,
-		"buildarch":     runtime.GOARCH,
-	}
-	if json, err := json.Marshal(m); err == nil {
-		c.metadata.setMetadata(json)
-	}
+	c.metadata.setMetadata(nc.Metadata)
 
 	if err := c.tcp.init(c, nc.Listen, nc.ReadTimeout); err != nil {
 		c.log.Println("Failed to start TCP interface")

src/yggdrasil/metadata.go

@@ -1,7 +1,9 @@
 package yggdrasil
 
 import (
+	"encoding/json"
 	"errors"
+	"runtime"
 	"sync"
 	"time"
 )
@@ -84,10 +86,29 @@ func (m *metadata) getMetadata() metadataPayload {
 }
 
 // Set the current node's metadata
-func (m *metadata) setMetadata(meta metadataPayload) {
+func (m *metadata) setMetadata(given interface{}) error {
 	m.myMetadataMutex.Lock()
 	defer m.myMetadataMutex.Unlock()
-	m.myMetadata = meta
+	newmeta := map[string]interface{}{
+		"buildname":     GetBuildName(),
+		"buildversion":  GetBuildVersion(),
+		"buildplatform": runtime.GOOS,
+		"buildarch":     runtime.GOARCH,
+	}
+	if metamap, ok := given.(map[string]interface{}); ok {
+		for key, value := range metamap {
+			if _, ok := newmeta[key]; ok {
+				continue
+			}
+			newmeta[key] = value
+		}
+	}
+	if newjson, err := json.Marshal(newmeta); err == nil {
+		m.myMetadata = newjson
+		return nil
+	} else {
+		return err
+	}
 }
 
 // Add metadata into the cache for a node