From 02a8d4f044609ae9ae0dc828e4cef3c760f67ad9 Mon Sep 17 00:00:00 2001
From: David Gageot <david@gageot.net>
Date: Mon, 18 Mar 2019 15:24:33 +0100
Subject: [PATCH] Compute tags in parallel

Signed-off-by: David Gageot <david@gageot.net>
---
 pkg/skaffold/runner/runner.go | 35 +++++++++++++++++++++++++++--------
 1 file changed, 27 insertions(+), 8 deletions(-)

diff --git a/pkg/skaffold/runner/runner.go b/pkg/skaffold/runner/runner.go
index 11d187222b0..962e5c94627 100644
--- a/pkg/skaffold/runner/runner.go
+++ b/pkg/skaffold/runner/runner.go
@@ -293,34 +293,53 @@ func (r *SkaffoldRunner) Run(ctx context.Context, out io.Writer, artifacts []*la
 	return nil
 }
 
+type tagErr struct {
+	tag string
+	err error
+}
+
 // imageTags generates tags for a list of artifacts
 func (r *SkaffoldRunner) imageTags(ctx context.Context, out io.Writer, artifacts []*latest.Artifact) (tag.ImageTags, error) {
 	start := time.Now()
 	color.Default.Fprintln(out, "Generating tags...")
 
-	tags := make(tag.ImageTags, len(artifacts))
+	tagErrs := make([]chan tagErr, len(artifacts))
+
+	for i := range artifacts {
+		tagErrs[i] = make(chan tagErr, 1)
+
+		i := i
+		go func() {
+			tag, err := r.Tagger.GenerateFullyQualifiedImageName(artifacts[i].Workspace, artifacts[i].ImageName)
+			tagErrs[i] <- tagErr{tag: tag, err: err}
+		}()
+	}
+
+	imageTags := make(tag.ImageTags, len(artifacts))
+
+	for i, artifact := range artifacts {
+		imageName := artifact.ImageName
+		color.Default.Fprintf(out, " - %s -> ", imageName)
 
-	for _, artifact := range artifacts {
 		select {
 		case <-ctx.Done():
 			return nil, context.Canceled
-		default:
-			imageName := artifact.ImageName
-			color.Default.Fprintf(out, " - %s -> ", imageName)
 
-			tag, err := r.Tagger.GenerateFullyQualifiedImageName(artifact.Workspace, imageName)
+		case t := <-tagErrs[i]:
+			tag := t.tag
+			err := t.err
 			if err != nil {
 				return nil, errors.Wrapf(err, "generating tag for %s", imageName)
 			}
 
 			fmt.Fprintln(out, tag)
 
-			tags[imageName] = tag
+			imageTags[imageName] = tag
 		}
 	}
 
 	color.Default.Fprintln(out, "Tags generated in", time.Since(start))
-	return tags, nil
+	return imageTags, nil
 }
 
 // BuildAndTest builds artifacts and runs tests on built artifacts