Let pre/post upgrade hook use extended watch

_proto/hapi/services/tiller.proto

@@ -58,7 +58,7 @@ service ReleaseService {
 	}
 
 	// UpdateRelease updates release content.
-	rpc UpdateRelease(UpdateReleaseRequest) returns (UpdateReleaseResponse) {
+	rpc UpdateRelease(UpdateReleaseRequest) returns (stream UpdateReleaseResponse) { // TODO: backward compatibility
 	}
 
 	// InstallRelease requests installation of a chart as a new release.
@@ -215,6 +215,7 @@ message UpdateReleaseRequest {
 // UpdateReleaseResponse is the response to an update request.
 message UpdateReleaseResponse {
 	hapi.release.Release release = 1;
+	hapi.release.WatchFeed watch_feed = 2; // TODO: think about compatibility
 }
 
 message RollbackReleaseRequest {

pkg/helm/client.go

@@ -443,7 +443,52 @@ func (h *Client) update(ctx context.Context, req *rls.UpdateReleaseRequest) (*rl
 	defer c.Close()
 
 	rlc := rls.NewReleaseServiceClient(c)
-	return rlc.UpdateRelease(ctx, req)
+
+	var finalResp *rls.UpdateReleaseResponse
+
+	currentLogHeader := ""
+	setLogHeader := func(logHeader string) {
+		if currentLogHeader != logHeader {
+			if currentLogHeader != "" {
+				fmt.Println()
+			}
+			fmt.Printf("%s\n", logHeader)
+			currentLogHeader = logHeader
+		}
+	}
+	formatJobHeader := func(jobName string, podName string, containerName string) string {
+		// tail -f on multiple files prints similar headers
+		return fmt.Sprintf("==> Job \"%s\", Pod \"%s\", Container \"%s\" <==", jobName, podName, containerName)
+	}
+
+	stream, err := rlc.UpdateRelease(ctx, req)
+	for {
+		resp, err := stream.Recv()
+		if err == io.EOF {
+			return finalResp, nil
+		}
+		if err != nil {
+			return resp, err
+		}
+
+		if resp.WatchFeed.GetJobLogChunk() != nil {
+			chunk := resp.WatchFeed.GetJobLogChunk()
+
+			setLogHeader(formatJobHeader(chunk.JobName, chunk.PodName, chunk.ContainerName))
+
+			for _, line := range chunk.LogLines {
+				fmt.Println(line.Data)
+			}
+		} else if resp.WatchFeed.GetJobPodError() != nil {
+			jobPodError := resp.WatchFeed.GetJobPodError()
+
+			setLogHeader(formatJobHeader(jobPodError.JobName, jobPodError.PodName, jobPodError.ContainerName))
+
+			fmt.Fprintf(os.Stderr, "Error: %s\n", jobPodError.Message)
+		} else {
+			finalResp = resp // TODO verify/debug this code
+		}
+	}
 }
 
 // Executes tiller.RollbackRelease RPC.