The basic Heroku build process fails for rpy2. The solution that I have found consists of the following:
- Set up the typical multi-buildpacks. This means running $ heroku buildpacks:set https://github.com/ddollar/heroku-buildpack-multi.git
- Add the following to .buildpacks http://github.com/ddimmery/heroku-buildpack-r.git#cedar-14 https://github.com/ddimmery/heroku-buildpack-python
- These two buildpacks are slightly modified from the default versions. In particular,
- The R buildpack is modified to ensure that the resulting $PATH environment variable is set to use the correct python executable
- The Python buildpack is modified to ensure that R is visible and usable when running
pip -r requirements.txt - That's basically it. I have no doubt that there's a better way to do this, but I was unable to see how.
This is forked from the official Heroku buildpack for Python apps, powered by pip and other excellent software.
Recommended web frameworks include Django and Flask. The recommended webserver is Gunicorn. There are no restrictions around what software can be used (as long as it's pip-installable). Web processes must bind to $PORT, and only the HTTP protocol is permitted for incoming connections.
Some Python packages with obscure C dependencies (e.g. scipy) are not compatible.
Deploying a Python application couldn't be easier:
$ ls
Procfile requirements.txt web.py
$ heroku create --buildpack heroku/python
$ git push heroku master
...
-----> Python app detected
-----> Installing python-2.7.11
$ pip install -r requirements.txt
Collecting requests (from -r requirements.txt (line 1))
Downloading requests-2.9.1-py2.py3-none-any.whl (501kB)
Installing collected packages: requests
Successfully installed requests-2.9.1
-----> Discovering process types
Procfile declares types -> (none)
A requirements.txt file must be present at the root of your application's repository.
You can also specify the latest production release of this buildpack for upcoming builds of an existing application:
$ heroku buildpacks:set heroku/python
Specific versions of the Python runtime can be specified with a runtime.txt file:
$ cat runtime.txt
python-3.5.1
Runtime options include:
python-2.7.11python-3.5.1pypy-4.0.1(unsupported, experimental)
Other unsupported runtimes are available as well. Use at your own risk.