Merge pull request #2145 from lavalamp/eventing2

Add a placeholder to boundPod's SelfLink

pkg/registry/etcd/etcd.go

@@ -229,23 +229,24 @@ func (r *Registry) assignPod(ctx api.Context, podID string, machine string) erro
 	if err != nil {
 		return err
 	}
-	// TODO: move this to a watch/rectification loop.
+	boundPod, err := r.boundPodFactory.MakeBoundPod(machine, finalPod)
-	pod, err := r.boundPodFactory.MakeBoundPod(machine, finalPod)
 	if err != nil {
 		return err
 	}
+	// Doing the constraint check this way provides atomicity guarantees.
 	contKey := makeContainerKey(machine)
 	err = r.AtomicUpdate(contKey, &api.BoundPods{}, func(in runtime.Object) (runtime.Object, error) {
-		pods := *in.(*api.BoundPods)
+		boundPodList := in.(*api.BoundPods)
-		pods.Items = append(pods.Items, *pod)
+		boundPodList.Items = append(boundPodList.Items, *boundPod)
-		if !constraint.Allowed(pods.Items) {
+		if !constraint.Allowed(boundPodList.Items) {
 			return nil, fmt.Errorf("The assignment would cause a constraint violation")
 		}
-		return &pods, nil
+		return boundPodList, nil
 	})
 	if err != nil {
-		// Put the pod's host back the way it was. This is a terrible hack that
+		// Put the pod's host back the way it was. This is a terrible hack, but
-		// won't be needed if we convert this to a rectification loop.
+		// can't really be helped, since there's not really a way to do atomic
+		// multi-object changes in etcd.
 		if _, err2 := r.setPodHostTo(ctx, podID, machine, ""); err2 != nil {
 			glog.Errorf("Stranding pod %v; couldn't clear host after previous error: %v", podID, err2)
 		}

pkg/registry/pod/bound_pod_factory.go

@@ -43,5 +43,9 @@ func (b *BasicBoundPodFactory) MakeBoundPod(machine string, pod *api.Pod) (*api.
 	for ix, container := range boundPod.Spec.Containers {
 		boundPod.Spec.Containers[ix].Env = append(container.Env, envVars...)
 	}
+	// Make a dummy self link so that references to this bound pod will work.
+	// TODO: When kubelets get boundPods from apiserver instead of etcd, then
+	// the selflink should be generated there.
+	boundPod.SelfLink = "/api/v1beta1/boundPods/" + boundPod.Name
 	return boundPod, nil
 }

pkg/registry/pod/bound_pod_factory_test.go

@@ -54,6 +54,10 @@ func TestMakeBoundPodNoServices(t *testing.T) {
 	if pod.Name != "foobar" {
 		t.Errorf("Failed to assign ID to pod: %#v", pod.Name)
 	}
+
+	if _, err := api.GetReference(pod); err != nil {
+		t.Errorf("Unable to get a reference to bound pod: %v", err)
+	}
 }
 
 func TestMakeBoundPodServices(t *testing.T) {