chore(deps): update docker/build-push-action digest to 9e436ba

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
docker/build-push-action	action	digest	ac9327e -> 9e436ba

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Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

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• If you want to rebase/retry this PR, check this box

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[github-actions]

Code Quality

1. Pinned version clarity: The updated commit hash 0788c444d8b4d67580213712e34a148cae3a6c4e refers to a specific version of the docker/build-push-action. While pinning by commit hash is a good practice for security, it's recommended to include a comment or reference in the code (or documentation) explaining why this specific version is chosen. This helps maintainers in the future understand the context of the change.

   Example:
   yaml
   uses: docker/build-push-action@0788c44 # Pinning to version X due to features/fixes in commit Y

2. Branch-based pinning consideration: While a commit hash ensures no unexpected changes, if you anticipate frequent updates to docker/build-push-action due to new features or security fixes, consider pinning to a trusted stable branch or tag (e.g., v4) instead of a hash. This reduces the need for frequent manual updates.

Security

• Commit Verification: Verify that the updated hash corresponds to a trusted and legitimate source from the GitHub docker/build-push-action repository. This prevents reliance on potentially malicious code.

Best Practice

1. Explicit platform options: The platforms option specifies linux/amd64,linux/arm64. If cross-platform builds aren't required, remove unused architecture(s) to reduce build time and carbon footprint. For instance:

   platforms: \"linux/amd64\"

   This change would lower resource use and operational costs if only amd64 builds are necessary.

Cost & Carbon Usage

• Context Efficiency: Specifying context: src/. narrows the Docker build context, which helps reduce carbon usage and computation. Confirm that only necessary build files are present in the src directory; remove unused files to minimize Docker image size, build time, and costs.

• Impact of multi-platform building: Multi-platform builds (e.g., amd64, arm64) inherently require more resources, potentially increasing CI pipeline execution time and costs. Estimated price changes could vary depending on the runner and additional workload but might range from an additional £0.10-£0.50 per multi-platform build. Environmentally, this results in higher carbon emissions.

Suggestions Summary

• Add a comment explaining the pinned commit hash for maintainability.
• Evaluate whether pinning to a tag/branch is more suitable than using a specific commit hash.
• Remove unused platforms if multi-platform support isn't required.
• Ensure the build context src/. contains only essential files to minimize Docker image size, time, and associated costs.

[github-actions]

Suggested Improvements

1. Pinning docker/build-push-action Version

   • While you updated the Git SHA, it is better to switch to a more reliable and less brittle versioning mechanism such as semver tags (v4, v4.1.2, etc.), if available. This ensures compatibility and avoids surprises when the SHA unexpectedly changes.

   Example:
   yaml
   uses: docker/build-push-action@v4

2. Cost and Carbon Usage Considerations

   • The current configuration builds for both linux/amd64 and linux/arm64. If you don't need these platforms for all deployments, consider reducing the target platforms to lower computational costs and carbon usage. For example, if arm64 isn't necessary:

   Example Update:

   platforms: \"linux/amd64\"

3. Add Caching for Docker Builds

   • Add a caching mechanism to reduce build times, save GitHub Actions minutes, and lower energy consumption.

   Example:

   with:
     context: src/.
     platforms: \"linux/amd64,linux/arm64\"
     cache-from: type=registry
     cache-to: type=inline

4. Security Best Practice

   • Double-check whether the GitHub action SHA (263435318d21b8e681c14492fe198d362a7d2c83) you are pinning is from a trusted source by verifying the commit in the repository to prevent potential supply chain vulnerabilities.

5. Documentation

   • Include a comment above the uses line explaining why this specific SHA was chosen or refer to the source of truth (e.g., changelog or release notes for that commit). This improves maintainability.

   Example:

   # Pinning to docker/[email protected] for stability and compatibility. See: https://github.com/docker/setup-buildx-action/releases
   uses: docker/[email protected]

Estimated Cost Impact

• Potential Savings: Reducing platform targets and enabling caching could lower GitHub Actions runtime, translating to cost and energy savings (~£0.02-£0.05 per additional build minute saved depending on usage).

Estimated Carbon Impact

• Caching and reducing unnecessary platform builds can reduce the carbon footprint by avoiding redundant computational resources, especially in cross-platform builds.