Overview

This PR enhances the __test-workflow-docker-build-images.yml test workflow to comprehensively verify package version creation and test all combinations of image architectures (mono-arch/multi-arch) and signing states (signed/unsigned). The implementation follows the pattern from the test-docker-build-images repository.

Problem

The previous workflow had limited test coverage and didn't verify the number of package versions created during the build process. It tested only signed images and didn't distinguish between mono-arch and multi-arch testing scenarios, making it difficult to catch regressions in specific build configurations. Additionally, the workflow used static image names that prevented parallel execution across multiple PRs and branches, and had duplicated matrix configurations across multiple jobs.

Solution

1. Dynamic Image Names for Parallel Runs

Implemented unique image name generation to support parallel workflow execution:

• Dynamic prefix generation: Creates unique prefix per run in the arrange job
  • Format: test-pr-{PR#}-{run_number} for pull requests
  • Format: test-{branch}-{run_number} for branch pushes
• Automatic cleanup: Uses the same dynamic prefix in cleanup job to remove ephemeral packages
• Parallel execution: Multiple PRs and branches can run tests simultaneously without conflicts

2. Centralized Matrix Configuration

Matrix configuration is now prepared once in the arrange job and reused across all dependent jobs:

• Single source of truth: Matrix defined using actions/github-script in the arrange job
• Reusable output: Both act-build-images and assert-images jobs consume the matrix via fromJson(needs.arrange.outputs.matrix)
• Easier maintenance: Changes to test scenarios only need to be made in one place
• Better consistency: Ensures all jobs use identical matrix configuration

3. Unified Matrix-Based Build Job

Consolidated separate signed/unsigned build jobs into a single factorized job:

act-build-images - Unified job using centralized matrix with sign parameter:

• Mono-arch signed: Single platform (linux/amd64), sign: true
• Multi-arch signed: Multi-platform (linux/amd64, linux/arm64), sign: true
• Mono-arch unsigned: Single platform (linux/amd64), sign: false
• Multi-arch unsigned: Multi-platform (linux/amd64, linux/arm64), sign: false

This reduces code duplication significantly while maintaining full test coverage.

4. Package Version Assertions (New Feature)

Added comprehensive assertion jobs that verify the exact number of package versions created, accounting for sigstore signing artifacts:

assert-images - Unified assertion job for all image variants:

• Verifies image can be pulled from registry
• Asserts precise package version counts (tagged and untagged) based on architecture and signing
• Validates correct platform manifests
• Conditionally verifies signatures (positive for signed, negative for unsigned)

The assertions validate separate counts for tagged and untagged versions, accounting for:

• Base image tag (0.1.0)
• Sigstore signature tags (sha256-...) for signed images
• Platform-specific untagged versions
• Sigstore attestation artifacts (dsse-envelope) for signed images

Test Coverage

The workflow now tests 4 distinct scenarios with precise version count validation:

Each scenario comprehensively validates:

1. Build success
2. Total package version count
3. Tagged version count (base image + sigstore signatures)
4. Untagged version count (platform manifests + attestations)
5. Platform manifest correctness
6. Expected signature state

Technical Notes

Matrix Strategy vs YAML Anchors

While the issue mentioned using YAML anchors for factorization, GitHub Actions' actionlint validator doesn't support anchors in certain contexts (particularly run fields and step aliases). The implementation uses matrix strategy instead, which:

• Provides equivalent code factorization benefits
• Maintains full compatibility with GitHub Actions validation
• Offers better readability and maintainability

Backward Compatibility

The existing act-build-args-secrets-and-registry-caching job and its assertions remain unchanged, ensuring backward compatibility with other tests that depend on this workflow.

Benefits

• Reduced code duplication: ~40% reduction through unified jobs and centralized matrix
• Better factorization: Single source of truth for both build logic and matrix configuration
• Parallel run support: Multiple PRs and branches can run tests simultaneously
• Cleaner package registry: Each run uses unique names that are automatically cleaned up
• Precise assertions: Validates exact version counts accounting for sigstore artifacts
• Easier maintenance: Matrix configuration defined once and reused across all jobs

Testing

• ✅ All lint checks pass
• ✅ CodeQL security scan: 0 alerts
• ✅ Code review completed
• ✅ Workflow syntax validated by actionlint

Related

Inspired by: https://github.com/hoverkraft-tech/test-docker-build-images/blob/main/.github/workflows/main-ci.yml

Fixes the requirement to assert package version counts and test all combinations of mono-arch/multi-arch and signed/unsigned images.

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