chore: add Docker deployment support

[philprime]

Docker Deployment with Multi-Registry Support

This PR adds comprehensive Docker deployment infrastructure with multi-architecture builds and dual registry publishing.

Features

Multi-Architecture Support

• 🏗️ Platforms: linux/amd64, linux/arm64
• 🔄 Digest-based builds: Platform-specific images combined into multi-arch manifests

Dual Registry Publishing

• 📦 GitHub Container Registry: ghcr.io/techprimate/github-actions-utils-cli
• 🐳 Docker Hub: docker.io/techprimate/github-actions-utils-cli

Modern Metadata Management

• 🏷️ OCI-compliant labels: Using docker/metadata-action@v5
• 📝 Annotations: Attached at manifest and index levels
• 🔖 Semantic versioning: Automatic version tags (latest, v1.0.0, 1.0, 1)

Workflow Structure

• ♻️ Reusable workflows: build-cli-docker.yml for maintainability
• 🧪 PR dry-run mode: Test Docker builds in pull requests
• ⚡ Build caching: Registry-based caching for faster builds

What's Included

New Files

• .dockerignore - Optimized build context
• Dockerfile - Multi-stage build with buildpack-deps:bookworm
• .github/workflows/build-cli-docker.yml - Reusable Docker build workflow

Updated Files

• .github/workflows/release.yml - Integrated Docker build workflow
• Makefile - New Docker targets (build-linux, docker-build, docker-test, docker-run)
• README.md - Docker usage instructions and examples
• AGENTS.md - Complete Docker deployment documentation

Docker Images

Registries

# Pull from GitHub Container Registry
docker pull ghcr.io/techprimate/github-actions-utils-cli:latest

# Pull from Docker Hub
docker pull docker.io/techprimate/github-actions-utils-cli:latest

Available Tags

• latest - Latest main branch build
• v1.0.0 - Specific version releases
• 1.0 - Major.minor version
• 1 - Major version

Image Details

• Base: buildpack-deps:bookworm (~200MB)
• Platforms: linux/amd64, linux/arm64
• Entry point: /usr/local/bin/github-actions-utils-cli

Usage Examples

MCP Client Configuration

{
  "mcpServers": {
    "github-actions-utils": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "ghcr.io/techprimate/github-actions-utils-cli:latest",
        "mcp"
      ]
    }
  }
}

Local Development

# Build Linux binaries
make build-linux

# Build Docker image
make docker-build

# Test Docker image
make docker-test

# Run interactively
make docker-run

Required Configuration

To enable Docker Hub publishing, add the following to repository settings:

Variables

• DOCKERHUB_USERNAME - Docker Hub username

Secrets

• DOCKERHUB_TOKEN - Docker Hub access token

Workflow Behavior

On Main Branch Push

• ✅ Builds multi-arch images
• ✅ Publishes to both registries
• ✅ Tags as latest

On Version Tag (e.g., v1.0.0)

• ✅ Builds multi-arch images
• ✅ Publishes to both registries
• ✅ Creates semantic version tags (1.0.0, 1.0, 1)

On Pull Request

• ✅ Builds images (validation only)
• ❌ Does not publish

Benefits

1. Easy Distribution - Users can pull pre-built images instead of building from source
2. Multi-Platform - Native support for both x86 and ARM architectures
3. High Availability - Images available on both GitHub and Docker Hub
4. Container Native - Perfect for containerized environments and CI/CD
5. Metadata Rich - OCI-compliant labels for better discoverability

Testing

The workflow includes comprehensive testing:

• Build validation on PRs
• Multi-platform builds
• Registry authentication
• Manifest creation and inspection

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Related: Closes any Docker deployment issues (if applicable)

[philprime]

@sentry review

[Copilot]

Pull Request Overview

This PR adds Docker container support to the GitHub Actions Utils CLI project, enabling deployment and distribution via Docker images published to GitHub Container Registry and Docker Hub.

• Adds Dockerfile for multi-platform container builds (linux/amd64, linux/arm64)
• Implements automated Docker image build and publish workflow via build-cli-docker.yml
• Adds Makefile targets for local Docker development and testing

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
Dockerfile	New multi-platform Dockerfile using buildpack-deps:bookworm base image with architecture-specific binary selection
.dockerignore	Excludes unnecessary files from Docker build context while allowing Linux binaries
Makefile	Adds build-linux, docker-build, docker-test, and docker-run targets for Docker workflows
.github/workflows/build-cli-docker.yml	New reusable workflow for building and publishing multi-platform Docker images to GHCR and Docker Hub
.github/workflows/release.yml	Integrates Docker build into release pipeline with pull request dry-run support
README.md	Documents Docker installation, usage, and development workflows
AGENTS.md	Documents Docker deployment details, image registries, and publishing process

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