Buildstep uses Docker and Buildpacks to build applications like Heroku
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Heroku-style application builds using Docker and Buildpacks. Used by Dokku to make a mini-Heroku.


  • Docker
  • Git

Supported Buildpacks

Buildpacks should generally just work, but many of them make assumptions about their environment. So Buildstep has a list of officially supported buildpacks that are built-in and ready to be used.

Building Buildstep

The buildstep script uses a buildstep base container that needs to be built. It must be created before you can use the buildstep script. To create it, run:

$ make build

This will create a container called progrium/buildstep that contains all supported buildpacks and the builder script that will actually perform the build using the buildpacks.

Building an App

Running the buildstep script will take an application tar via STDIN and an application container name as an argument. It will put the application in a new container based on progrium/buildstep with the specified name. Then it runs the builder script inside the container.

$ cat myapp.tar | ./buildstep myapp

The resulting container has a built app ready to go. The builder script also parses the Procfile and produces a starter script that takes a process type. Run your app with:

$ docker run -d myapp /bin/bash -c "/start web"

Adding Buildpacks

Buildstep needs to support a buildpack by installing packages needed to run the build and to run the application it builds. For example, the Python buildpack would need Python to be installed.

To add a new buildpack to buildstep, add commands to install the necessary packages that the buildpack and built application environment will need to stack/packages.txt and stack/prepare. Then add the buildpack Git URL to the file stack/buildpacks.txt

You'll then have to re-build.