Merge pull request #2452 from weaveworks/mike/docker-swarm/service-ns-selector

Add docker swarm Stack selector ala k8s namespace selector

probe/docker/reporter.go

@@ -23,6 +23,7 @@ const (
 	ImageTableID     = "image_table"
 	ServiceName      = "service_name"
 	StackNamespace   = "stack_namespace"
+	DefaultNamespace = "No Stack"
 )
 
 // Exposed for testing

probe/docker/tagger.go

@@ -59,12 +59,12 @@ func (t *Tagger) Tag(r report.Report) (report.Report, error) {
 		}
 		stackNamespace, ok := container.Latest.Lookup(LabelPrefix + "com.docker.stack.namespace")
 		if !ok {
-			continue
-		}
-
-		prefix := stackNamespace + "_"
-		if strings.HasPrefix(serviceName, prefix) {
-			serviceName = serviceName[len(prefix):]
+			stackNamespace = DefaultNamespace
+		} else {
+			prefix := stackNamespace + "_"
+			if strings.HasPrefix(serviceName, prefix) {
+				serviceName = serviceName[len(prefix):]
+			}
 		}
 
 		nodeID := report.MakeSwarmServiceNodeID(serviceID)