Heroku buildpack: Buildout

This is a Heroku buildpack for Python apps, powered by Buildout.

Usage

Example usage, first create a Heroku app:

$ heroku create

This buildpack depends on the official Heroku Python buildpack, so you need to configure your app with support for multi-buildpacks, by setting the following environment variable:

$ heroku config:set BUILDPACK_URL=https://github.com/ddollar/heroku-buildpack-multi.git

Then specify the list of buildpacks your app should use in the .buildpacks file:

$ cat .buildpacks
https://github.com/heroku/heroku-buildpack-python.git
https://github.com/niteoweb/heroku-buildpack-buildout.git

The buildpack will detect your app as a Buildout-powered-Python app if the repo has buildout.cfg file in the root. The python buildpack will download the specific Python version and create a virtualenv. The buildout buildpack downloads bootstrap.py and then use Buildout to build your environment.

$ cat buildout.cfg
[buildout]
relative-paths = true
...

Note that you have to set relative-paths = true in your buildout.cfg file.

Next, you need to tell Heroku how to run your app once Buildout builds it:

$ cat Procfile
bin/<your app start command>

Lastly, push your changes to Heroku to build your app:

$ git push heroku master
...
-----> Fetching custom git buildpack... done
-----> Buildout app detected
-----> Use build cache
-----> Read BUILDOUT_CFG from env vars, or use default
-----> Read BUILDOUT_VERBOSITY from env vars, or use default
-----> Read BOOTSTRAP_PY_URL from env vars, or use default
-----> Init buildout
...
-----> Run bin/buildout -c buildout.cfg
...
-----> Copy results to cache
-----> Copy results to slug
       Done
-----> Discovering process types
       Procfile declares types -> web

Options

Set Python version

You can set an arbitrary Python version with a runtime.txt file. You need an empty requirements.txt file to trigger the python buildpack. An empty requirements.txt and a runtime.txt is only needed if you want to use a specific Python version. If those files are missing, it will simply use the globally installed Python.

$ cat runtime.txt
python-2.7.8

Runtime options include:

• python-2.6.9
• python-3.4.1
• pypy-1.9 (experimental)

Other unsupported runtimes are available as well.

Set Buildout verbosity

To increase the Buildout's verbosity, set the following environment variable:

$ heroku config:add BUILDOUT_VERBOSITY=-v

You can increase verbosity up to -vvvv.

Use arbitrary *.cfg file

To run an arbitrary *.cfg file such as heroku.cfg, set the following environment variable:

$ heroku config:add BUILDOUT_CFG=heroku.cfg

Note that you have to set relative-paths = true in your arbitrary *.cfg file.

Use arbitrary bootstrap.py file

By default, this buildpack uses the following bootstrap.py file to bootstrap the Buildout 2.x environment on Heroku: http://downloads.buildout.org/2/bootstrap.py

If you want to use some other bootstrap.py, for example to enable support for Buildout version 1.x, set the BOOTSTRAP_PY_URL environment variable.

$ heroku config:add BOOTSTRAP_PY_URL=http://downloads.buildout.org/2/bootstrap.py