Stop using wireguard in cluster.go

The wireguard is mostly used to compute metadata.
Metadata is now computed by main.go and encoded in
node.go, the cluster only receives a function generating
the binary metadata.

cluster.go

@@ -27,14 +27,14 @@ type ClusterState struct {
 type cluster struct {
 	localName string // used to avoid LocalNode(); should not change
 	ml        *memberlist.Memberlist
-	wg        *wgState
+	getMeta   func(int) []byte
 	state     *ClusterState
 	events    chan memberlist.NodeEvent
 }
 
 const statePath = "/var/lib/wesher/state.json"
 
-func newCluster(config *config, wg *wgState) (*cluster, error) {
+func newCluster(config *config, getMeta func(int) []byte) (*cluster, error) {
 	clusterKey := config.ClusterKey
 
 	state := &ClusterState{}
@@ -70,7 +70,7 @@ func newCluster(config *config, wg *wgState) (*cluster, error) {
 	cluster := cluster{
 		localName: ml.LocalNode().Name,
 		ml:        ml,
-		wg:        wg,
+		getMeta:   getMeta,
 		// The big channel buffer is a work-around for https://github.com/hashicorp/memberlist/issues/23
 		// More than this many simultaneous events will deadlock cluster.members()
 		events: make(chan memberlist.NodeEvent, 100),
@@ -80,9 +80,6 @@ func newCluster(config *config, wg *wgState) (*cluster, error) {
 	mlConfig.Events = &memberlist.ChannelEventDelegate{Ch: cluster.events}
 	mlConfig.Delegate = &cluster
 
-	wg.assignOverlayAddr((*net.IPNet)(config.OverlayNet), cluster.localName)
-
-	ml.UpdateNode(1 * time.Second) // we currently do not update after creation
 	return &cluster, nil
 }
 
@@ -90,6 +87,10 @@ func (c *cluster) NotifyConflict(node, other *memberlist.Node) {
 	logrus.Errorf("node name conflict detected: %s", other.Name)
 }
 
+func (c *cluster) NodeMeta(limit int) []byte {
+	return c.getMeta(limit)
+}
+
 // none of these are used
 func (c *cluster) NotifyMsg([]byte)                           {}
 func (c *cluster) GetBroadcasts(overhead, limit int) [][]byte { return nil }
@@ -117,6 +118,10 @@ func (c *cluster) leave() {
 	c.ml.Shutdown() //nolint: errcheck
 }
 
+func (c *cluster) update() {
+	c.ml.UpdateNode(1 * time.Second) // we currently do not update after creation
+}
+
 func (c *cluster) members() (<-chan []node, <-chan error) {
 	changes := make(chan []node)
 	errc := make(chan error, 1)

main.go

@@ -2,6 +2,7 @@ package main // import "github.com/costela/wesher"
 
 import (
 	"fmt"
+	"net"
 	"os"
 	"os/signal"
 	"syscall"
@@ -34,10 +35,19 @@ func main() {
 		logrus.WithError(err).Fatal("could not instantiate wireguard controller")
 	}
 
-	cluster, err := newCluster(config, wg)
+	getMeta := func(limit int) []byte {
+		return encodeNodeMeta(nodeMeta{
+			OverlayAddr: wg.OverlayAddr,
+			PubKey:      wg.PubKey.String(),
+		}, limit)
+	}
+
+	cluster, err := newCluster(config, getMeta)
 	if err != nil {
 		logrus.WithError(err).Fatal("could not create cluster")
 	}
+	wg.assignOverlayAddr((*net.IPNet)(config.OverlayNet), cluster.localName)
+	cluster.update()
 
 	nodec, errc := cluster.members() // avoid deadlocks by starting before join
 	if err := backoff.RetryNotify(

node.go

@@ -26,12 +26,9 @@ func (n *node) String() string {
 	return n.Addr.String()
 }
 
-func (c *cluster) NodeMeta(limit int) []byte {
+func encodeNodeMeta(nm nodeMeta, limit int) []byte {
 	buf := &bytes.Buffer{}
-	if err := gob.NewEncoder(buf).Encode(nodeMeta{
-		OverlayAddr: c.wg.OverlayAddr,
-		PubKey:      c.wg.PubKey.String(),
-	}); err != nil {
+	if err := gob.NewEncoder(buf).Encode(nm); err != nil {
 		logrus.Errorf("could not encode local state: %s", err)
 		return nil
 	}