dh-virtualenv
Contents
- Overview
- Presentations, Blogs & Other Resources
- Using dh-virtualenv
- How does it work?
- Running tests
- Building the package in a Docker container
- Building the documentation locally
- Releasing a new version
- Code of conduct
- License
Overview
dh-virtualenv is a tool that aims to combine Debian packaging with self-contained virtualenv based Python deployments.
The idea behind dh-virtualenv is to be able to combine the power of Debian packaging with the sandboxed nature of virtualenvs. In addition to this, using virtualenv enables installing requirements via Python Package Index instead of relying on the operating system provided Python packages. The only limiting factor is that you have to run the same Python interpreter as the operating system.
For complete online documentation including installation instructions, see the online documentation.
Presentations, Blogs & Other Resources
Here are a few external resources that can help you to get a more detailed first impression of dh-virtualenv, or advocate its use in your company or project team.
- How We Deploy Python Code – Building, packaging & deploying Python using versioned artifacts in Debian packages at Nylas.
- DevOps Tool Bazaar – Slide deck presented at the DevOps Karlsruhe Meetup in February 2018, regarding Python software deployment for Debian with a practical example.
- The Architecture of Open Source Applications: Python Packaging – This provides a lot of background (and possibly things you didn't know) about the Python side of packaging.
Using dh-virtualenv
Using dh-virtualenv is fairly straightforward. First, you need to define the requirements of your package in requirements.txt
file, in the format defined by pip.
To build a package using dh-virtualenv, you need to add dh-virtualenv in to your build dependencies and write following debian/rules
file:
%:
dh $@ --with python-virtualenv
Note that you might need to provide additional build dependencies too, if your requirements require them.
Also, you are able to define the root path for your source directory using --sourcedirectory
or -D
argument:
%:
dh $@ --with python-virtualenv --sourcedirectory=root/srv/application
NOTE: Be aware that the configuration in debian/rules expects tabs instead of spaces!
Once the package is built, you have a virtualenv contained in a Debian package and upon installation it gets placed, by default, under /opt/venvs/<packagename>
.
For more information and usage documentation, check the accompanying documentation in the doc
folder, also available at Read the Docs.
How does it work?
To do the packaging, dh-virtualenv extends debhelper's sequence by inserting a new dh_virtualenv
command, which effectively replaces the following commands in the original sequence:
dh_auto_clean
dh_auto_build
dh_auto_test
dh_auto_install
dh_python2
dh_pycentral
dh_pysupport
In the new sequence, dh_virtualenv
is inserted right before dh_installinit
.
Running tests
$ nosetests ./test/test_deployment.py
Building the package in a Docker container
To build dh-virtualenv
itself in a Docker container, call docker build --tag dh-venv-builder .
. This will build the DEB package for Debian stable by default. Add e.g. --build-arg distro=ubuntu:bionic
to build for Ubuntu LTS instead.
The resulting files must be copied out of the build container, using these commands:
mkdir -p dist && docker run --rm dh-venv-builder tar -C /dpkg -c . | tar -C dist -xv
There is also a short-cut for all this, in the form of invoke bdist_deb [--distro=‹id›:‹codename›]
.
Building the documentation locally
If you execute the following commands in your clone of the repository, a virtualenv with all necessary tools is created. invoke docs
then builds the documentation into doc/_build/
.
command . .env --yes --develop
invoke docs
To start a watchdog that auto-rebuilds documentation and reloads the opened browser tab on any change, call invoke docs -w -b
(stop the watchdog using the -k
option).
Releasing a new version
Follow these steps when creating a new release:
- Check version in
dh_virtualenv/_version.py
anddebian/changelog
. - Make sure
doc/changes.rst
is complete. - Bump release date in
debian/changelog
(dch -r
). - Tag the release and
git push --tags
. - Edit release entry on GitHub (add changes).
- Update the Ubuntu PPA.
- Bump to next release version in
dh_virtualenv/_version.py
. - Open new section in
debian/changelog
(with…-0.1+dev
added). - Open a new section in
doc/changes.rst
, so it can be maintained as features are added!
Code of conduct
This project adheres to the Open Code of Conduct. By participating, you are expected to honor this code.
License
Copyright (c) 2013-2017 Spotify AB
dh-virtualenv is licensed under GPL v2 or later. Full license is available in the LICENSE
file.