Heroku-style application builds using Docker and Buildpacks. Used by Dokku to make a mini-Heroku.
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.
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
If you didn't already have an application tar, you can create one on the fly.
$ tar cC /path/to/your/app . | ./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"
Custom buildpacks can be installed by committing a file in the root of your git repository named
This file should contain a line
export BUILDPACK_URL=<repository> specifying the git repository providing
If your buildpack needs extra packages these can be installed by the buildpack using bin/compile.