Merge pull request #27511 from quinton-hoole/2016-06-15-improve-logging-in-federation-service-controller

Automatic merge from submit-queue

Improve error logging on DNS updates for federated services

This makes debugging easier.  Prior to this, the logs would e.g. contain "Successfully updated 4 out of 4 DNS records", when in fact zero DNS records had been successfully updated.  It's difficult to debug what's happening with such confusing log messages.

federation/pkg/federation-controller/service/servicecontroller.go

@@ -707,18 +707,23 @@ func (s *ServiceController) updateDNSRecords(services []*cachedService, clusters
 
 // lockedUpdateDNSRecords Updates the DNS records of a service, assuming we hold the mutex
 // associated with the service.
-// TODO: quinton: Still screwed up in the same way as above.  Fix.
 func (s *ServiceController) lockedUpdateDNSRecords(service *cachedService, clusterNames []string) error {
 	if !wantsDNSRecords(service.appliedState) {
 		return nil
 	}
+	ensuredCount := 0
 	for key := range s.clusterCache.clientMap {
 		for _, clusterName := range clusterNames {
 			if key == clusterName {
 				s.ensureDnsRecords(clusterName, service)
+				ensuredCount += 1
 			}
 		}
 	}
+	if ensuredCount < len(clusterNames) {
+		return fmt.Errorf("Failed to update DNS records for %d of %d clusters for service %v due to missing clients for those clusters",
+			len(clusterNames)-ensuredCount, len(clusterNames), service)
+	}
 	return nil
 }