Docker Image policy plugin

docker-image-policy is a Docker Access authorization plugin written Go to control which Images are allowed to be pulled by your Docker daemon. The plugin is using the AuthZPlugin API by Docker. Black and Whitelistings are expressed through regular expression. A default policy if no listing matched can be defined also.

Supported: Docker Engine >= 1.11

Building

To build this plugin Go >= 1.7 and proper GOPATH setup is required.

$ make

Build Debian Package

PACKAGES WILL BE INSTALLED

Please consider using a Docker container for building the Debian package.

$ sudo sh build-deb.sh

Example with Docker container:

$ git clone [email protected]:freach/docker-image-policy-plugin.git ~/docker-image-policy-plugin
$ docker run -it --rm -v ~/docker-image-policy-plugin:/go golang bash
$ sh build-deb.sh
$ ls *.deb

Get started

Plugin configuration

Add a config file (default: /etc/docker/docker-image-policy.json), and configure the plugin like so:

{
  "whitelist": [
    "^alpine:",
    "^docker\\.elastic\\.co/beats/filebeat:",
    "^gcr\\.io/google_containers",
    "^mysql:",
    "^nginx:",
    "^php:",
    "^apache:",
    "^quay\\.io/calico/cni",
    "^quay\\.io/calico/node",
    "^quay\\.io/coreos/flannel"
  ],
  "blacklist": [
    "^docker:"
  ],
  "defaultAllow": false
}

The whitelist and blacklist array expect strings in regex format. Image pull requests will be checked by applying the compiled regular expressions on the full image, < repository >:< tag >. Certain characters in a regular expression like "." have special meaning and need to be escaped. The JSON format requires you to double escape.

Image pull requests will be handled in the following order:

1. Whitelist: Allow explicitly white listed images
2. Blacklist: Reject explicitly black listed images
3. defaultAllow: Default policy, if true allow, if false reject

If one of the steps matched, the plugin will return accordingly. If whitelist and blacklist did not match, the default policy defaultAllow will allow or reject the request.

Docker configuration

Edit your /etc/docker/daemon.json

{
  "authorization-plugins": ["docker-image-policy"]
}

Running

Start docker-image-policy and restart Docker daemon.

$ docker-image-policy &
$ curl localhost:5006/health
$ service docker restart

Please consider using the systemd service file for running docker-image-policy

API Endpoints

Besides the plugin API for Docker a second API provided through 127.0.0.1:5006 (default) is available to monitor the plugin or check the current state.

• /health -> Health check
• /config -> Current config
• /version -> Current version

$ curl localhost:5006/health
HEALTHY

Author

• Simon Pirschel