From 97fe285adad8e343c7d2d7c44fcd07d9d633970c Mon Sep 17 00:00:00 2001
From: Jacob LeGrone <git@jacob.work>
Date: Sat, 20 Jul 2019 13:14:01 -0400
Subject: [PATCH] feat(client): wait for Pods during hook execution

Signed-off-by: Jacob LeGrone <git@jacob.work>
---
 pkg/kube/client.go    | 31 ++++++++++++++++++++++++++++++-
 pkg/kube/interface.go |  5 +++--
 2 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/pkg/kube/client.go b/pkg/kube/client.go
index 4aa817af3..2162f083f 100644
--- a/pkg/kube/client.go
+++ b/pkg/kube/client.go
@@ -255,6 +255,8 @@ func (c *Client) watchTimeout(t time.Duration) func(*resource.Info) error {
 //
 // - Jobs: A job is marked "Ready" when it has successfully completed. This is
 //   ascertained by watching the Status fields in a job's output.
+// - Pods: A pod is marked "Ready" when it has successfully completed. This is
+//   ascertained by watching the status.phase field in a pod's output.
 //
 // Handling for other kinds will be added as necessary.
 func (c *Client) WatchUntilReady(reader io.Reader, timeout time.Duration) error {
@@ -435,8 +437,11 @@ func (c *Client) watchUntilReady(timeout time.Duration, info *resource.Info) err
 			// the status go into a good state. For other types, like ReplicaSet
 			// we don't really do anything to support these as hooks.
 			c.Log("Add/Modify event for %s: %v", info.Name, e.Type)
-			if kind == "Job" {
+			switch kind {
+			case "Job":
 				return c.waitForJob(e, info.Name)
+			case "Pod":
+				return c.waitForPodSuccess(e, info.Name)
 			}
 			return true, nil
 		case watch.Deleted:
@@ -474,6 +479,30 @@ func (c *Client) waitForJob(e watch.Event, name string) (bool, error) {
 	return false, nil
 }
 
+// waitForPodSuccess is a helper that waits for a pod to complete.
+//
+// This operates on an event returned from a watcher.
+func (c *Client) waitForPodSuccess(e watch.Event, name string) (bool, error) {
+	o, ok := e.Object.(*v1.Pod)
+	if !ok {
+		return true, errors.Errorf("expected %s to be a *v1.Pod, got %T", name, e.Object)
+	}
+
+	switch o.Status.Phase {
+	case v1.PodSucceeded:
+		fmt.Printf("Pod %s succeeded\n", o.Name)
+		return true, nil
+	case v1.PodFailed:
+		return true, errors.Errorf("pod %s failed", o.Name)
+	case v1.PodPending:
+		fmt.Printf("Pod %s pending\n", o.Name)
+	case v1.PodRunning:
+		fmt.Printf("Pod %s running\n", o.Name)
+	}
+
+	return false, nil
+}
+
 // scrubValidationError removes kubectl info from the message.
 func scrubValidationError(err error) error {
 	if err == nil {
diff --git a/pkg/kube/interface.go b/pkg/kube/interface.go
index 72d7a0ea9..53da50b8b 100644
--- a/pkg/kube/interface.go
+++ b/pkg/kube/interface.go
@@ -21,7 +21,7 @@ import (
 	"time"
 )
 
-// KubernetesClient represents a client capable of communicating with the Kubernetes API.
+// Interface represents a client capable of communicating with the Kubernetes API.
 //
 // A KubernetesClient must be concurrency safe.
 type Interface interface {
@@ -41,7 +41,8 @@ type Interface interface {
 
 	// Watch the resource in reader until it is "ready".
 	//
-	// For Jobs, "ready" means the job ran to completion (excited without error).
+	// For Jobs, "ready" means the Job ran to completion (exited without error).
+	// For Pods, "ready" means the Pod phase is marked "succeeded".
 	// For all other kinds, it means the kind was created or modified without
 	// error.
 	WatchUntilReady(reader io.Reader, timeout time.Duration) error