Add setup-weaver GitHub Action for CI/CD

[kuklyy]

Fixes #879

Summary

Add reusable GitHub Action for installing Weaver CLI in CI/CD workflows.

Motivation

Projects using Weaver need a simple, reliable way to install it in GitHub Actions across different platforms.

What's included

• Action: .github/actions/setup-weaver/ - Cross-platform Weaver installation
• Testing: .github/workflows/test-setup-weaver-action.yml - Automated testing on Linux/macOS/Windows
• Documentation: Complete README with usage examples and troubleshooting

Features

• Cross-platform support (Linux, macOS, Windows)
• Automatic version resolution (latest or pinned)
• Binary caching for faster CI runs
• Simple API with minimal configuration

Usage

steps:
  - uses: actions/checkout@v4
  - uses: open-telemetry/weaver/.github/actions/setup-weaver@main
  - run: weaver registry check -r ./model

Testing

See opentelemetry-weaver-examples for real-world usage examples.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 79.4%. Comparing base (1511626) to head (426f73d).
⚠️ Report is 12 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #1036     +/-   ##
=======================================
+ Coverage   78.7%   79.4%   +0.7%     
=======================================
  Files         82      82             
  Lines       6612    7033    +421     
=======================================
+ Hits        5204    5586    +382     
- Misses      1408    1447     +39     

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[thompson-tomo]

I like being able to offer a github action I however after reading https://docs.github.com/en/actions/how-tos/create-and-publish-actions/publish-in-github-marketplace I see 1 issue when we go to publish it to the marketplace which is that it is not in a seperate repo.

This could cause us problems due to the reliance on git tags, what would happen if we did a release for the action, what that break the ability to fetch the latest weaver? Also what would happen when weaver reaches v1.0.0.

Hence might be beneficial to request a seperate repo for this functionality ie weaver-setup.

[kuklyy]

I like being able to offer a github action I however after reading https://docs.github.com/en/actions/how-tos/create-and-publish-actions/publish-in-github-marketplace I see 1 issue when we go to publish it to the marketplace which is that it is not in a seperate repo.

We don't need to publish to Marketplace for this to work. Users can reference it directly:

- uses: open-telemetry/weaver/.github/actions/setup-weaver@main

Marketplace publishing (and potentially moving to a separate repo) could be considered post-v1.0.0 for increased discoverability. For now, the direct repo path keeps things simple while still enabling easier usage for Weaver users.

[lquerel]

LGTM

[jerbly]

This is nice! Once this is merged I'll review the weaver-examples PR - but that looks good too. Thanks!

[thompson-tomo]

@kuklyy sure it can be used without marketplace however using your example this would likely lead to issues with this rule https://github.com/ossf/scorecard/blob/c22063e786c11f9dd714d777a687ff7c4599b600/docs/checks.md#pinned-dependencies

Is it possible to use a tag rather than simply pointing it to main which would hopefully mitigate that rule?

[kuklyy]

Is it possible to use a tag rather than simply pointing it to main which would hopefully mitigate that rule?

Yes, users can reference the action using any git ref (e.g. tag, branch, or commit SHA). The choice of pinning strategy is up to the user - it's not something setup-weaver itself controls.

Note that pinning the action version (e.g., @main) is separate from pinning the Weaver version, which is controlled via the action's version input parameter.

Could you please elaborate on what specific change you'd like to see in the Action? Are you suggesting we add documentation about pinning best practices, or something else?