Building packages with dh-virtualenv

Building packages with dh-virtualenv is relatively easy to start with but it also supports lot of customization to fit in your general needs.

By default, dh-virtualenv installs your packages under /usr/share/python/<packagename>. The package name is provided by the debian/control file.

Simple usecase

To signal debhelper to use dh-virtualenv for building your package, you need to pass --with python-virtualenv to debhelper sequencer.

In a nutshell, the simplest debian/rules file to build using dh-virtualenv looks like this:

#!/usr/bin/make -f

%:
      dh $@ --with python-virtualenv

However, the tool makes a few assumptions of your project’s structure:

  • For installing requirements, you need to have a file called requirements.txt in the root directory of your project. The requirements file is not mandatory.
  • The project must have a setup.py file in the root of the project. Sequencer will run setup.py install to install the package inside the virtualenv.

After these are place, you can just build the package with your favorite tool!

Command line options

To change the default behavior the dh_virtualenv command accepts a few command line options:

-p <package>, --package <package>

Act on the package named <package>

-N <package>, --no-package <package>

Do not act on the specified package

-v, --verbose

Turn on verbose mode. This has a few effects: it sets root logger level to DEBUG and passes verbose flag to pip when installing packages. This can also be provided using the standard DH_VERBOSE environment variable.

--extra-index-url <url>

Use extra index url <url> when running pip to install packages. This can be provided multiple times to pass multiple URLs to pip. This is useful if you for example have a private Python Package Index.

--preinstall <package>

Package to install before processing the requirements. This flag can be used to provide a package that is installed by pip before processing requirements file. This is handy if you need to install for example a custom setup script or other packages needed to parse setup.py. This flag can be provided multiple times to pass multiple packages for pre-install.

--pypi-url <URL>

Base URL of the PyPI server. This flag can be used to pass in a custom URL to a PyPI mirror. It’s useful if you for example have an internal mirror of the PyPI or you run a special instance that only exposes selected packages of PyPI. If this is not provided, the default will be whatever pip uses as default (usually http://pypi.python.org/simple).

--setuptools

Use setuptools instead of distribute in the virtualenv

Advanced usage

To provide command line options to dh_virtualenv sequence the override mechanism of the debhelper is the best tool.

Following debian/rules will provide http://example.com as additional Python Package Index URI:

#!/usr/bin/make -f

%:
      dh $@ --with python-virtualenv

override_dh_virtualenv:
      dh_virtualenv --extra-index-url http://example.com