Add more logging

Fix issue when trying to update with an empty address
Fix govet issues
Run IPv6 poller

cmd/cloud-dyndns-client/main.go

@@ -174,7 +174,7 @@ func main() {
 	records := []sync.Record{}
 	for name, d := range cfg.Domains {
 		if !strings.HasSuffix(name, ".") {
-			name = name + "."
+			name += "."
 		}
 		records = append(records, constructRecord(name, d)...)
 	}
@@ -196,6 +196,7 @@ func main() {
 	// TODO: Refactor and move this code to it's own package
 	wg.Go(func() error { return syncer.Run(ctx.Done()) })
 	wg.Go(func() error { return IP4Poller.Run(ctx.Done()) })
+	wg.Go(func() error { return IP6Poller.Run(ctx.Done()) })
 	wg.Go(func() error {
 		// This goroutine receives IP address polling results
 		// and updates the desired records in the Syncer.
@@ -204,6 +205,7 @@ func main() {
 		for {
 			select {
 			case ip := <-ip4c:
+				log.Printf("Updating IPv4: %v", ip)
 				for _, r := range records {
 					if r.Record.Type() == "A" {
 						syncer.UpdateRecord(
@@ -215,6 +217,7 @@ func main() {
 					}
 				}
 			case ip := <-ip6c:
+				log.Printf("Updating IPv6: %v", ip)
 				for _, r := range records {
 					if r.Record.Type() == "AAAA" {
 						syncer.UpdateRecord(
@@ -272,7 +275,7 @@ func main() {
 	signal.Notify(signals, syscall.SIGINT, syscall.SIGTERM)
 	select {
 	case s := <-signals:
-		log.Printf("Received signal %v, exiting...", s)
+		log.Printf("Received %v signal, exiting...", s)
 	case <-ctx.Done():
 	}
 	cancel()

pkg/sync/ipaddress.go

@@ -74,6 +74,7 @@ func (i *IPAddressPoller) poll() error {
 	if err != nil {
 		return fmt.Errorf("could not obtain IP address: %w", err)
 	}
+	log.Printf("Found IP %v", ip)
 	for _, c := range i.channels {
 		select {
 		case c <- ip.String():

pkg/sync/sync.go

@@ -89,7 +89,7 @@ func NewSyncer(records []Record, pollInterval, apiTimeout time.Duration) *Syncer
 	}
 }
 
-// UpdateRecord() updates a managed record so that it can be synced by the
+// UpdateRecord updates a managed record so that it can be synced by the
 // sync loop.
 func (s *Syncer) UpdateRecord(dnsName, dnsType string, ttl int64, data []string) error {
 	for _, d := range s.domains {
@@ -109,10 +109,10 @@ func (s *Syncer) UpdateRecord(dnsName, dnsType string, ttl int64, data []string)
 		}
 	}
 
-	return fmt.Errorf("Domain %s not registered.", dnsName)
+	return fmt.Errorf("domain %s not registered.", dnsName)
 }
 
-// needsUpdate() compares the left/local DNSRecord against the right/remote
+// needsUpdate compares the left/local DNSRecord against the right/remote
 // DNSRecord and returns true if the record needs to be updated in the remote
 // backend.
 func needsUpdate(l, r backend.DNSRecord) bool {
@@ -135,7 +135,7 @@ func needsUpdate(l, r backend.DNSRecord) bool {
 	lData := l.Data()
 	rData := r.Data()
 
-	if len(lData) <= 0 {
+	if len(lData) < 1 {
 		return false
 	}
 
@@ -152,7 +152,7 @@ func needsUpdate(l, r backend.DNSRecord) bool {
 	return false
 }
 
-// pollSingle() performs a single refresh of the remote cache value.
+// pollSingle performs a single refresh of the remote cache value.
 func (s *Syncer) pollSingle(d *domainObj) error {
 	// Update record sets to reconcile
 	ctx := context.Background()
@@ -173,7 +173,7 @@ func (s *Syncer) pollSingle(d *domainObj) error {
 	return nil
 }
 
-// poll() runs a loop to poll the backend and update the remote cache.
+// poll runs a loop to poll the backend and update the remote cache.
 func (s *Syncer) poll(d *domainObj, stopCh <-chan struct{}) {
 	// Start by polling the domain to initialize the remote value and local cache
 	// TODO: Implement some exponential retry backoff logic in case poll interval is long
@@ -192,14 +192,14 @@ func (s *Syncer) poll(d *domainObj, stopCh <-chan struct{}) {
 	}
 }
 
-// syncSingle() syncs a single record entry, updating it with
+// syncSingle syncs a single record entry, updating it with
 // the backend server if necessary.
 func (s *Syncer) syncSingle(d *domainObj) error {
 	d.lock.Lock()
 	defer d.lock.Unlock()
 
 	// Sanity check
-	if !needsUpdate(d.managed, d.remote) {
+	if !needsUpdate(d.managed, d.remote) || len(d.managed.Data()) < 1 || len(d.managed.Data()) < 1 {
 		return nil
 	}
 
@@ -223,7 +223,7 @@ func (s *Syncer) syncSingle(d *domainObj) error {
 	return nil
 }
 
-// sync() runs a loop to sync records with backend providers
+// sync runs a loop to sync records with backend providers
 // when necessary.
 func (s *Syncer) sync(d *domainObj, stopCh <-chan struct{}) {
 	for {
@@ -246,7 +246,7 @@ func (s *Syncer) sync(d *domainObj, stopCh <-chan struct{}) {
 	}
 }
 
-// Run() starts the sync and poll loops
+// Run starts the sync and poll loops
 func (s *Syncer) Run(stopCh <-chan struct{}) error {
 	// Run a sync and poll loop for each domain. Sync and poll loops are
 	// separated so that polling and syncing do not block on each other.