Parse metadata outside of cluster.go

Move the calls for metadata decoding from the cluster
membership management loop to the main loop. This task
was not directly related to the cluster, and was adding
complexity, including the need for multierr structures.

cluster.go

@@ -15,7 +15,6 @@ import (
 	"github.com/mattn/go-isatty"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
-	"go.uber.org/multierr"
 )
 
 // ClusterState keeps track of information needed to rejoin the cluster
@@ -120,9 +119,8 @@ 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) {
+func (c *cluster) members() <-chan []node {
 	changes := make(chan []node)
-	errc := make(chan error, 1)
 	go func() {
 		for {
 			event := <-c.events
@@ -140,31 +138,22 @@ func (c *cluster) members() (<-chan []node, <-chan error) {
 			}
 
 			nodes := make([]node, 0)
-			var errs error
 			for _, n := range c.ml.Members() {
 				if n.Name == c.localName {
 					continue
 				}
-				meta, err := decodeNodeMeta(n.Meta)
-				if err != nil {
-					errs = multierr.Append(errs, err)
-					continue
-				}
 				nodes = append(nodes, node{
 					Name: n.Name,
 					Addr: n.Addr,
-					nodeMeta: meta,
+					Meta: n.Meta,
 				})
 			}
 			c.state.Nodes = nodes
 			changes <- nodes
-			if errs != nil {
-				errc <- errs
-			}
 			c.saveState()
 		}
 	}()
-	return changes, errc
+	return changes
 }
 
 func computeClusterKey(state *ClusterState, clusterKey []byte) ([]byte, error) {

go.mod

@@ -16,7 +16,6 @@ require (
 	github.com/stevenroose/gonfig v0.1.5
 	github.com/stretchr/testify v1.4.0 // indirect
 	github.com/vishvananda/netlink v1.1.0
-	go.uber.org/multierr v1.5.0
 	golang.zx2c4.com/wireguard/wgctrl v0.0.0-20200324154536-ceff61240acf
 )
 

main.go

@@ -49,7 +49,7 @@ func main() {
 	wg.assignOverlayAddr((*net.IPNet)(config.OverlayNet), cluster.localName)
 	cluster.update()
 
-	nodec, errc := cluster.members() // avoid deadlocks by starting before join
+	nodec := cluster.members() // avoid deadlocks by starting before join
 	if err := backoff.RetryNotify(
 		func() error { return cluster.join(config.Join) },
 		backoff.NewExponentialBackOff(),
@@ -65,9 +65,17 @@ func main() {
 	logrus.Debug("waiting for cluster events")
 	for {
 		select {
-		case nodes := <-nodec:
+		case rawNodes := <-nodec:
 			logrus.Info("cluster members:\n")
-			for _, node := range nodes {
+			nodes := make([]node, 0)
+			for _, node := range rawNodes {
+				meta, err := decodeNodeMeta(node.Meta)
+				if err != nil {
+					logrus.Warnf("\t addr: %s, could not decode metadata", node.Addr)
+					continue
+				}
+				node.nodeMeta = meta
+				nodes = append(nodes, node)
 				logrus.Infof("\taddr: %s, overlay: %s, pubkey: %s", node.Addr, node.OverlayAddr, node.PubKey)
 			}
 			if err := wg.setUpInterface(nodes); err != nil {
@@ -79,8 +87,6 @@ func main() {
 					logrus.WithError(err).Error("could not write hosts entries")
 				}
 			}
-		case errs := <-errc:
-			logrus.WithError(errs).Error("could not receive node info")
 		case <-incomingSigs:
 			logrus.Info("terminating...")
 			cluster.leave()

node.go

@@ -19,6 +19,7 @@ type nodeMeta struct {
 type node struct {
 	Name string
 	Addr net.IP
+	Meta []byte
 	nodeMeta
 }