gcloud-builds-tag-deploy-false-success

gcloud builds submit --tag false-success trap

Problem

A common Cloud Run deploy recipe looks like this:

gcloud builds submit --tag us-central1-docker.pkg.dev/PROJECT/REPO/IMAGE:latest
gcloud run services update SERVICE \
  --image us-central1-docker.pkg.dev/PROJECT/REPO/IMAGE:latest \
  --region us-central1 --project PROJECT

When the first command fails (most commonly because the current working directory doesn't contain a Dockerfile), its single-line error scrolls off-screen above the second command's verbose progress spinner. The second command then pulls the existing :latest image from Artifact Registry — which is the previous build — and deploys it. You get:

✓ Deploying... Done.
  ✓ Creating Revision...
  ✓ Routing traffic...
Service [...] revision [...] has been deployed and is serving 100 percent of traffic.

A green "SUCCESS" deploy that did not change the running code. The user then spends hours debugging why the fix isn't live, or worse, concludes the fix doesn't work and reverts good code.

Context / Trigger Conditions

• User reports "I deployed the fix but production behavior is unchanged"
• Recent shell output contains both:
  • ERROR: (gcloud.builds.submit) Invalid value for [source]: Dockerfile required when specifying --tag
  • revision [...] has been deployed and is serving 100 percent of traffic
• The gcloud builds submit --tag … was run without a source positional argument AND the working directory does not contain the Dockerfile (common in monorepos where the Dockerfile lives under a subdirectory like cloud-run-upload/, services/api/, etc.)
• The deploy targets use the mutable :latest tag (or another tag that already exists in the registry)

Root cause

gcloud builds submit --tag IMAGE_TAG needs a source directory. When you omit it, it defaults to the current working directory, and if there's no Dockerfile there (or a cloudbuild.yaml), it exits immediately with exit code 1 — without uploading anything, without creating a build job, without touching Artifact Registry.