docker-cartridge-examples

This repository contains example cartridges and prototyping for Docker based cartridges in OpenShift. For more information about the design and implementation, see the Docker cartridges PEP.

The platform directory contains a simple proof of concept implementation of a build system which creates runnable Docker images from cartridge 'manifests' and source code for an app. The cartridges directory contains the Dockerfiles and manifests of several example cartridges:

1. fedora-wildfly and its builder fedora-wildfly-build
2. ubuntu-buildpack
3. fedora-mock
4. centos-ruby2

Building

You can build a base image for a cartridge using the build command:

sudo ./build <cartridge-name>

Preparing a gear image

Once your cartridge image is built, you can prepare a gear image using the prepare command:

sudo ./prepare <username> <cartridge-name> <path to source>

This will create a gear image with the tag <username>/<cartridge-name>-app.

Running a gear image

You can run a gear image with the run command:

sudo ./run <username> <app-name> <cartridge-name>

This will run the gear image with the required ports bound to dynamically allocated ports on the host machine.

Earlier R&D

The cartridges directory also contains a number of preliminary example "cartridges" which are simply a Dockerfile (representing the base cartridge) and a cartridge.sh script that pre-date the POC prepare script. They implement the following workflow:

1. Build the cartridge into an image
2. "Prepare" the cartridge by injecting the source and invoking a script to build/deploy the source
3. Save that image as the gear image, suitable for deployment
4. Start the image

There are several ruby examples - Ruby 1.8.7 and 2.0.0 on CentOS, and then a Heroku Ruby Buildpack example. Each of these uses the same source and provides the same running Ruby Rack application - but under the covers they're all doing different things to make that possible, and each can offer unique advantages.