Heroku Java Docker Image

This Docker project is used to test Java applications on Heroku's cedar-14 stack. It can be used to run any kind of Java-based application (Java, Scala, Groovy, etc), regardless of the Buildpack used on Heroku.

Usage

Build the Heroku cedar-14 image:

./build.sh

This will build a Docker image with the tag "heroku/java".

Then, from your application directory run this to start a container:

$ docker run --publish 5000:5000 -it -v `pwd`:/app --rm heroku/java

The command above will detect your project's Procfile and run the web process.

Browse to http://localhost:5000 in you are on Linux, or http://boot2docker-ip:5000 on Mac.

Running Other Process Types

To run process types (in your Procfile) other than web, just add the name of process type to the run command like this:

$ docker run -it -v `pwd`:/app --rm heroku/java worker

Build the image with only one JDK

By default, the image will install JDK 6, 7, and 8 (and then decided which one to use based on your application's settings). But if you know you will only need one version of the JDK, you can define it in a system.properties in the root directory of this project. For example, the file might contain:

java.runtime.version=1.7