feat: add buildkit-version parameter to install custom BuildKit

[adityamaru]

Summary

Adds support for specifying a custom BuildKit version to install and use, addressing the requirement to boot Blacksmith builder with specific BuildKit versions (e.g., v0.16.0).

Changes

• ✅ Added buildkit-version input parameter to action.yml
• ✅ Implemented BuildKit installer that downloads specific versions from GitHub releases
• ✅ Updated setup_builder to use custom buildkitd binary path if specified
• ✅ Added comprehensive test workflows for different BuildKit versions
• ✅ Updated README with buildkit-version documentation

How It Works

When buildkit-version is specified:

1. The action downloads the specified BuildKit version from GitHub releases
2. Installs the BuildKit binaries to /usr/local/bin/
3. Uses the custom buildkitd binary instead of the system default

Example usage:

- uses: useblacksmith/setup-docker-builder@v1
  with:
    buildkit-version: "v0.16.0"  # Downloads and uses BuildKit v0.16.0

Test Workflows

The PR includes test workflows that verify:

• Installing and using BuildKit v0.16.0
• Installing and using BuildKit v0.18.0
• Backwards compatibility (uses system default when not specified)

Linear Issue

Addresses BLA-1827

This implementation allows users to override the system BuildKit version with any version available from the moby/buildkit GitHub releases.

🤖 Generated with Claude Code

[linear]

BLA-1827 Investigate missing driver-opts support in setup-docker-builder

[adityamaru]

1 Job Failed:

CI / Build and Test

Step "Install dependencies" from job "Build and Test" is failing. The last 20 log lines are:

[...]
npm ci
shell: /usr/bin/bash -e {0}
env:
  GITHUB_REPO_NAME: useblacksmith/setup-docker-builder
npm warn EBADENGINE Unsupported engine {
npm warn EBADENGINE   package: 'vite@7.1.2',
npm warn EBADENGINE   required: { node: '^20.19.0 || >=22.12.0' },
npm warn EBADENGINE   current: { node: 'v20.16.0', npm: '10.8.1' }
npm warn EBADENGINE }
npm warn deprecated @actions/cache@3.3.0: Please upgrade to v4 or higher. See https://github.com/actions/toolkit/discussions/1890 for more details.
npm error code E404
npm error 404 Not Found - GET https://buf.build/gen/npm/v1/@buf/blacksmith_vm-agent.connectrpc_es/-/blacksmith_vm-agent.connectrpc_es-1.6.1-20250304023716-e8d233d92eac.2.tgz - Not Found
npm error 404
npm error 404  '@buf/blacksmith_vm-agent.connectrpc_es@https://buf.build/gen/npm/v1/@buf/blacksmith_vm-agent.connectrpc_es/-/blacksmith_vm-agent.connectrpc_es-1.6.1-20250304023716-e8d233d92eac.2.tgz' is not in this registry.
npm error 404
npm error 404 Note that you can also install from a
npm error 404 tarball, folder, http url, or git url.
npm error A complete log of this run can be found in: /home/runner/.npm/_logs/2025-08-16T18_08_28_392Z-debug-0.log
Error: Process completed with exit code 1.

---

Summary: 7 successful workflows, 1 failed workflow

• ✅ Lint (1 job succeeded)
• ✅ Build and Test (1 job succeeded)
• ✅ Test BuildKit Version (3 jobs succeeded)
• ✅ Test Action (1 job succeeded)
• ✅ Verify Build Output (1 job succeeded)
• ✅ Test Driver Options (1 job succeeded)
• ✅ Test Driver Options Demo (2 jobs succeeded)
• ❌ CI (1 job failed)

Last updated: 2025-08-16 20:34:44 UTC

[adityamaru]

1 Job Failed:

CI / Build and Test

No logs available for this step.

---

Summary: 7 successful workflows, 1 failed workflow

• ✅ Test BuildKit Version (3 jobs succeeded)
• ✅ Test Action (1 job succeeded)
• ✅ Lint (1 job succeeded)
• ✅ Build and Test (1 job succeeded)
• ✅ Verify Build Output (1 job succeeded)
• ✅ Test Driver Options (1 job succeeded)
• ❌ CI (1 job failed)
• ✅ Test Driver Options Demo (2 jobs succeeded)

Last updated: 2025-08-16 20:34:44 UTC