.. _config-files:

Supported configuration files
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Below is a list of supported configuration files.

.. contents::
   :local:
   :depth: 1

``requirements.txt``
^^^^^^^^^^^^^^^^^^^^

This specifies a list of python packages that would be installed in a virtualenv (or conda environment).

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````````````````
::

   numpy==1.7
   matplotlib==2.1

``environment.yml``
^^^^^^^^^^^^^^^^^^^

This is a conda environment specification, that lets you install packages with conda.

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````````````````
::

  channels:
    - conda-forge
    - defaults
  dependencies:
    - matplotlib
    - pip:
      - sphinx-gallery

.. important::

   You must leave the ``environment.yml``'s name field empty for this
   to work out of the box.

``apt.txt``
^^^^^^^^^^^

A list of debian packages that should be installed. The base image used is usually the latest released
version of Ubuntu (currently Zesty.)

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::

   cowsay
   fortune

``postBuild``
^^^^^^^^^^^^^

A script that can contain arbitrary commands to be run after the whole repository has been built. If you
want this to be a shell script, make sure the first line is `#!/bin/bash`.

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````````````````
::

   wget <url-to-dataset>
   python myfile.py

.. note::

   This file must be executable to be used with ``repo2docker``. To do this,
   run the following::

     chmod +x postBuild

``REQUIRE``
^^^^^^^^^^^

This specifies a list of Julia packages!

.. note::

   Using a ``REQUIRE`` file also requires that the repository contain an
   ``environment.yml`` file.

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````````````````
::

  PyPlot
  Stats

``runtime.txt``
^^^^^^^^^^^^^^^

This allows you to control the runtime of Python. To use Python 2,
put the line ``python-2.7`` in the file. A Python 2 kernel will be installed
alongside Python 3.

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````````````````
::

   python-2.7

``Dockerfile``
^^^^^^^^^^^^^^

This will be treated as a regular Dockerfile and a regular Docker build will be performed.
The presence of a Dockerfile prevents all other build behavior.
See the `Binder Documentation <https://mybinder.readthedocs.io/en/latest/dockerfile.html>`_ for
best-practices with Dockerfiles.