ci: optimize staging image builds and increase promotion timeout

[janetkuo]

What this PR does / why we need it:

Optimizes staging image builds and increases the release promotion polling timeout to prevent CI pipeline failures during scheduled releases. Specifically:

1. Increase polling timeout: Bumps the per-image staging registry polling timeout in dev/tools/tag-promote-images from 45 to 90 minutes to accommodate slower Prow postsubmit builds.
2. Increase compute resources: Bumps the Google Cloud Build machine type in cloudbuild.yaml from E2_HIGHCPU_8 to E2_HIGHCPU_32 (32 vCPUs, 32 GB RAM) to accelerate C/Python dependency compilation.
3. Enable registry caching: Configures docker buildx in dev/tools/push-images to push and pull layer cache manifests (type=registry) to/from the K8s staging Artifact Registry (:buildcache), allowing subsequent Prow builds to instantly reuse pre-compiled Python wheels and base layers.
4. Fix workflows issue: add pyyaml dependency for crd sorting during release publish

Which issue(s) this PR is related to:

NONE

Release Note

NONE

Summary by CodeRabbit

• Chores
  • Increased Cloud Build machine capacity to improve compilation performance.
  • Enabled Docker Buildx registry caching to speed up image builds.
  • Extended image promotion registry polling timeout to 90 minutes to improve reliability.
• Documentation
  • Added an extra Python dependency during draft release generation.

[netlify]

❌ Deploy Preview for agent-sandbox failed. Why did it fail? →

Name	Link
🔨 Latest commit	d2a8ee3
🔍 Latest deploy log	https://app.netlify.com/projects/agent-sandbox/deploys/6a3afad393eb5d000824cb97

[coderabbitai]

📝 Walkthrough

Walkthrough

Cloud Build VM machineType is upgraded from E2_HIGHCPU_8 to E2_HIGHCPU_32. The push-images script gains Docker Buildx --cache-from/--cache-to registry cache flags when using registry output. The tag-promote-images staging-registry polling loop is doubled from 45 to 90 iterations (90-minute max wait), with the timeout status message updated accordingly. The release workflow's manifest generation step adds pyyaml==6.0.2 as a Python dependency.

Changes

CI Build Pipeline Improvements

Layer / File(s)	Summary
Build machine size and Buildx registry cache cloudbuild.yaml, dev/tools/push-images	machineType changed to E2_HIGHCPU_32; push-images computes a buildcache image reference and appends --cache-from and --cache-to type=registry,mode=max to the buildx command when output type is registry.
Staging registry polling timeout doubled dev/tools/tag-promote-images	get_latest_digest loop count changed from 45 to 90, doubling the maximum wait from 45 to 90 minutes; adjacent timeout comment updated to match.
Release workflow Python dependency .github/workflows/release.yml	Added pyyaml==6.0.2 to the pip install command in the publish-draft job's manifest generation step.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

Poem

🐇 Hop, hop! The machine grows strong and wide,
With 32 cores to power the ride.
Cache layers stack up, registry-bound,
While polling waits longer — patience profound.
And yaml comes too, for releases to glide! 🏗️

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely summarizes the main changes: optimizing staging image builds and increasing the promotion timeout, which aligns with all three key modifications in the changeset.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description check	✅ Passed	The pull request description follows the template structure with clear sections explaining what the PR does, why it's needed, related issues, and release notes.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[Copilot]

Pull request overview

This PR tunes the release/CI image pipeline to be more resilient and faster in staging by increasing promotion polling timeouts, allocating more Cloud Build CPU, and enabling docker buildx registry-backed layer caching for repeat builds.

Changes:

• Increase staging registry polling window in tag-promote-images from 45 to 90 minutes per image.
• Configure dev/tools/push-images to publish and consume a registry cache manifest (:buildcache) when pushing images via buildx.
• Increase Cloud Build machine type to E2_HIGHCPU_32 to speed dependency compilation-heavy image builds.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
dev/tools/tag-promote-images	Extends the staging registry polling loop to wait longer for postsubmit-built images.
dev/tools/push-images	Adds buildx --cache-from/--cache-to registry caching to accelerate subsequent image builds.
cloudbuild.yaml	Upsizes Cloud Build machine type to reduce overall image build time.

[aditya-shantanu]

/lgtm
/approve

[kubernetes-prow]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: aditya-shantanu, janetkuo

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Details

Needs approval from an approver in each of these files:

• OWNERS [janetkuo]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[janetkuo]

Suspect the Netlify build failures coming from #660 (review). This PR didn't make site changes.

[janetkuo]

/label tide/merge-method-rebase

[shrutiyam-glitch]

/lgtm

[Copilot]

Pull request overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.