Merge pull request #4 from robfrank/claude/add-docker-registry-support-011WXEv8yLYPdLuRrgtoRjk5

Author: robfrank

README.md

@@ -3,11 +3,12 @@
 [![Test](https://github.com/robfrank/kamal-accessories-updater/actions/workflows/test.yml/badge.svg)](https://github.com/robfrank/kamal-accessories-updater/actions/workflows/test.yml)
 [![Release](https://github.com/robfrank/kamal-accessories-updater/actions/workflows/release.yml/badge.svg)](https://github.com/robfrank/kamal-accessories-updater/actions/workflows/release.yml)
 
-A GitHub Action that automatically checks for and updates [Kamal](https://kamal-deploy.org/) accessories to their latest versions from Docker Hub.
+A GitHub Action that automatically checks for and updates [Kamal](https://kamal-deploy.org/) accessories to their latest versions from Docker Hub, GitHub Container Registry (GHCR), and other OCI registries.
 
 ## Features
 
-- 🔍 **Automatic Version Detection** - Scans your Kamal deployment configurations for accessories and checks Docker Hub for latest versions
+- 🔍 **Automatic Version Detection** - Scans your Kamal deployment configurations for accessories and checks registries for latest versions
+- 🌐 **Multi-Registry Support** - Works with Docker Hub, GitHub Container Registry (ghcr.io), and other OCI-compliant registries
 - 📦 **Semantic Versioning** - Intelligently compares semantic versions to ensure only newer versions are applied
 - 🔒 **SHA256 Support** - Automatically fetches and includes SHA256 digests for enhanced security
 - 📝 **Pull Request Creation** - Optionally creates pull requests with detailed update information
@@ -139,11 +140,12 @@ Check for updates and create a PR:
 
 1. **Scans Configuration Files** - Finds all `deploy*.yml` files in your config directory
 2. **Extracts Accessories** - Parses YAML to identify accessories and their current versions
-3. **Checks Docker Hub** - Queries Docker Hub API for latest semantic versions
-4. **Compares Versions** - Intelligently compares versions to determine if updates are available
-5. **Fetches Digests** - Retrieves SHA256 digests for the latest versions
-6. **Updates Files** - Modifies your configuration files with new versions and digests
-7. **Creates PR** - Optionally creates a pull request with the changes
+3. **Detects Registry** - Automatically detects the registry (Docker Hub, GHCR, etc.) from the image name
+4. **Queries Registry API** - Fetches latest semantic versions from the appropriate registry
+5. **Compares Versions** - Intelligently compares versions to determine if updates are available
+6. **Fetches Digests** - Retrieves SHA256 digests for the latest versions
+7. **Updates Files** - Modifies your configuration files with new versions and digests
+8. **Creates PR** - Optionally creates a pull request with the changes
 
 ## Supported Accessories
 
@@ -156,37 +158,112 @@ This action works with any Docker image used as a Kamal accessory. Common exampl
 - BusyBox (`busybox`)
 - Any custom Docker image on Docker Hub
 
+## Supported Registries
+
+The action supports multiple container registries:
+
+### Docker Hub (docker.io)
+
+**Default registry** - No authentication required for public images.
+
+```yaml
+accessories:
+  redis:
+    image: redis:7.0.0                    # Official image (implicit docker.io)
+
+  custom:
+    image: myorg/myapp:1.0.0             # Organization image
+
+  explicit:
+    image: docker.io/library/postgres:15 # Explicit registry prefix
+```
+
+### GitHub Container Registry (ghcr.io)
+
+**Requires authentication** for most operations. Set the `GHCR_TOKEN` environment variable with a GitHub Personal Access Token (PAT) or use the automatic `GITHUB_TOKEN`.
+
+```yaml
+accessories:
+  myapp:
+    image: ghcr.io/myorg/myapp:1.0.0
+
+  public:
+    image: ghcr.io/owner/public-image:2.0.0
+```
+
+**GitHub Action Configuration for GHCR:**
+
+```yaml
+- name: Update accessories
+  uses: robfrank/kamal-accessories-updater@v1
+  with:
+    config-dir: config
+  env:
+    GHCR_TOKEN: ${{ secrets.GITHUB_TOKEN }}  # Use GitHub token for GHCR access
+```
+
+**For private GHCR images**, create a GitHub PAT with `read:packages` scope:
+
+```yaml
+env:
+  GHCR_TOKEN: ${{ secrets.GHCR_PAT }}  # Use custom PAT for private images
+```
+
+### Other Registries
+
+The action includes detection for:
+- **Google Container Registry** (gcr.io)
+- **Quay.io** (quay.io)
+- **Generic OCI registries** (basic support)
+
+Support for additional registries is being actively developed. Open an issue if you need support for a specific registry.
+
 ## Configuration File Format
 
 Your Kamal configuration files should follow the standard format:
 
 ```yaml
 accessories:
+  # Docker Hub - official image (default registry)
   redis:
     image: redis:7.0.0
     host: 192.168.0.1
     # ... other configuration
 
+  # Docker Hub - with SHA256 digest
   postgres:
     image: postgres:15.0@sha256:abc123...
     host: 192.168.0.1
     # ... other configuration
+
+  # GitHub Container Registry
+  myapp:
+    image: ghcr.io/myorg/myapp:1.2.3@sha256:def456...
+    host: 192.168.0.1
+    # ... other configuration
+
+  # Docker Hub - organization image
+  custom:
+    image: mycompany/myservice:2.0.0
+    host: 192.168.0.1
+    # ... other configuration
 ```
 
 The action will:
+- Automatically detect the registry from the image name
 - Preserve your existing configuration structure
 - Update only the image version
 - Add or update SHA256 digests
 - Keep all other settings intact
 
 ## Caching
 
-The action caches Docker Hub API responses for 1 hour to:
+The action caches registry API responses for 1 hour to:
 - Reduce API calls
 - Improve performance
 - Avoid rate limiting
 
-Cache is stored in `/tmp/docker-registry-cache` and automatically cleaned up.
+Cache is stored in `/tmp/docker-registry-cache` and automatically cleaned up. Each registry is cached separately to ensure accuracy.
 
 ## Testing
 
@@ -256,6 +333,8 @@ This project is licensed under the MIT License - see the [LICENSE](LICENSE) file
 - [Kamal Documentation](https://kamal-deploy.org/)
 - [Kamal Accessories Guide](https://kamal-deploy.org/docs/configuration/accessories/)
 - [Docker Hub API](https://docs.docker.com/registry/spec/api/)
+- [GitHub Container Registry](https://docs.github.com/en/packages/working-with-a-github-packages-registry/working-with-the-container-registry)
+- [OCI Distribution Spec](https://github.com/opencontainers/distribution-spec)
 
 ## Acknowledgments