Merge pull request hashicorp#19 from hashicorp/bugfix/7

Define sync channels without creating and closing them

subcommand/sync-catalog/command.go

@@ -116,8 +116,7 @@ func (c *Command) Run(args []string) int {
 	ctx, cancelF := context.WithCancel(context.Background())
 
 	// Start the K8S-to-Consul syncer
-	toConsulCh := make(chan struct{})
-	close(toConsulCh)
+	var toConsulCh chan struct{}
 	if c.flagToConsul {
 		// Build the Consul sync and start it
 		syncer := &catalogFromK8S.ConsulSyncer{
@@ -149,8 +148,7 @@ func (c *Command) Run(args []string) int {
 	}
 
 	// Start Consul-to-K8S sync
-	toK8SCh := make(chan struct{})
-	close(toK8SCh)
+	var toK8SCh chan struct{}
 	if c.flagToK8S {
 		sink := &catalogFromConsul.K8SSink{
 			Client:    clientset,
@@ -187,20 +185,28 @@ func (c *Command) Run(args []string) int {
 	// Unexpected exit
 	case <-toConsulCh:
 		cancelF()
-		<-toK8SCh
+		if toK8SCh != nil {
+			<-toK8SCh
+		}
 		return 1
 
 	// Unexpected exit
 	case <-toK8SCh:
 		cancelF()
-		<-toConsulCh
+		if toConsulCh != nil {
+			<-toConsulCh
+		}
 		return 1
 
 	// Interrupted, gracefully exit
 	case <-sigCh:
 		cancelF()
-		<-toConsulCh
-		<-toK8SCh
+		if toConsulCh != nil {
+			<-toConsulCh
+		}
+		if toK8SCh != nil {
+			<-toK8SCh
+		}
 		return 0
 	}
 }