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
/opt/venvs/<packagename>
. The package name is provided by
the debian/control
file.
To use an alternative install prefix, add a line like
export DH_VIRTUALENV_INSTALL_ROOT=</your/custom/install/dir>
to the top of your debian/rules
file. dh_virtualenv will use
DH_VIRTUALENV_INSTALL_ROOT
instead of /opt/venvs
when it constructs the install path.
To use an install suffix other than the package name, call the
dh_virtualenv
command using the --install-suffix
command
line option. See Advanced Usage for further information on passing
options.
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 runsetup.py install
to install the package inside the virtualenv.
After these are place, you can just build the package with your favorite tool!
Environment variables¶
Certain environment variables can be used to customise the behaviour of the debhelper sequencer in addition to the standard debhelper variables.
-
DH_VIRTUALENV_INSTALL_ROOT
¶ Define a custom root location to install your package(s). The resulting location for a specific package will be ``/path/to/install/root/<packagename>` unless
--install-suffix
is used.
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 topip
when installing packages. This can also be provided using the standardDH_VERBOSE
environment variable.
-
--install-suffix
<suffix>
¶ Override virtualenv installation suffix. The suffix is appended to
/opt/venvs
, or theDH_VIRTUALENV_INSTALL_ROOT
environment variable if specified, to construct the installation path.
-
--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 topip
. 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 parsesetup.py
. This flag can be provided multiple times to pass multiple packages for pre-install.
-
--pip-tool
<exename>
¶ Executable that will be used to install requirements after the preinstall stage. Usually you’ll install this program by using the
--preinstall
argument. The replacement is expected to be found in the virtualenv’s bin/ directory.
-
--upgrade-pip
<package>
¶ New in version 1.0.
Force upgrading pip to the latest available release. Note: This can produce non-repeatable builds.
-
--index-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 (usuallyhttp://pypi.python.org/simple
).
-
--extra-pip-arg
<PIP ARG>
¶ Extra parameters to pass to the pip executable. This is useful if you need to change the behaviour of pip during the packaging process. You can use this flag multiple times to pass in different pip flags. As an example passing in
--extra-pip-arg
“–no-compile” to the override_dh_virtualenv section of the debian/rules file will disable the generation of pyc files.
-
--extra-virtualenv-arg
<VIRTUALENV ARG>
¶ Extra parameters to pass to the virtualenv executable. This is useful if you need to change the behaviour of virtualenv during the packaging process. You can use this flag multiple times to pass in different virtualenv flags.
-
--requirements
<REQUIREMENTS FILE>
¶ Use a different requirements file when installing. Some packages such as pbr expect the
requirements.txt
file to be a simple list of requirements that can be copied verbatim into theinstall_requires
list. This command option allows specifying a differentrequirements.txt
file that may include pip specific flags such as-i
,-r-
and-e
.
-
--setuptools
¶
Use setuptools instead of distribute in the virtualenv
-
--setuptools-test
¶
New in version 1.0.
Run
python setup.py test
when building the package. This was the old default behaviour before version 1.0. This option is incompatible with the deprecated--no-test
.
-
--python
<path>
¶ Use a specific Python interpreter found in
path
as the interpreter for the virtualenv. Default is to use the system default, usually/usr/bin/python
.
-
--builtin-venv
¶
Enable the use of the build-in
venv
module, i.e. usepython -m venv
to create the virtualenv. For this to work, requires Python 3.4 or later to be used, e.g. by using the option--python
/usr/bin/python3.4
. (Python 3.3 has thevenv
module, but virtualenvs created with Python 3.3 are not bootstrapped with setuptools or pip.)
-
-S
,
--use-system-packages
¶
Enable the use of system site-packages in the created virtualenv by passing the
--system-site-packages
flag tovirtualenv
.
-
--skip-install
¶
Skip running
pip install .
after dependencies have been installed. This will result in anything specified in setup.py being ignored. If this package is intended to install a virtualenv and a program that uses the supplied virtualenv, it is up to the user to ensure that if setup.py exists, any installation logic or dependencies contained therein are handled.This option is useful for web application deployments where the package is expected contain the virtual environment to support an application which itself may be installed via some other means – typically, by the packages
./debian/<packagename>.install
file, possibly into a directory structure unrelated to the location of the virtual environment.
-
--pypi-url
<URL>
¶ Deprecated since version 1.0: Use
--index-url
instead.
-
--no-test
¶
Deprecated since version 1.0: This option has no effect. See
--setuptools-test
.
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
Experimental buildsystem support¶
Important: Following chapters describe a completely experimental functionality of dh-virtualenv.
Starting with version 0.9 of dh-virtualenv, there is a buildsystem alternative.
The main difference in use is that instead of the --with python-virtualenv
option, --buildsystem=dh_virtualenv
is passed to debhelper. The debian rules
file should look like this:
#!/usr/bin/make -f
%:
dh $@ --buildsystem=dh_virtualenv
Using the buildsystem instead of the part of the sequence (in other
words, instead of the --with python-virtualenv
) one can get more
flexibility into the build process.
Flexibility comes from the fact that buildsystem will have individual
steps for configure, build, test and install and those can be
overridden by adding override_dh_auto_<STEP>
target into the
debian/rules
file. For example:
#!/usr/bin/make -f
%:
dh $@ --buildsystem=dh_virtualenv
override_dh_auto_test:
py.test test/
In addition the separation of build and install steps makes it
possible to use debian/install
files to include built files into
the Debian package. This is not possible with the sequencer addition.
The build system honors the DH_VIRTUALENV_INSTALL_ROOT
environment variable. Following other environment variables can be
used to customise the functionality:
-
DH_VIRTUALENV_ARGUMENTS
¶ Pass given extra arguments to the
virtualenv
commandFor example:
export DH_VIRTUALENV_ARGUMENTS="--no-site-packages --always-copy"
The default is to create the virtual environment with
--no-site-packages
.
-
DH_REQUIREMENTS_FILE
¶ New in version 1.0.
Override the location of requirements file. See
--requirements
.
-
DH_UPGRADE_PIP
¶ New in version 1.0.
Force upgrade of the
pip
tool by settingDH_UPGRADE_PIP
to empty (latest version) or specific version. For example:
-
DH_UPGRADE_SETUPTOOLS
¶ New in version 1.0.
Force upgrade of setuptools by setting
DH_UPGRADE_SETUPTOOLS
to empty (latest version) or specific version.
-
DH_UPGRADE_WHEEL
¶ New in version 1.0.
Force upgrade of wheel by setting
DH_UPGRADE_WHEEL
to empty (latest version) or specific version.
-
DH_PIP_EXTRA_ARGS
¶ New in version 1.0.
Pass additional parameters to the
pip
command. For example:export DH_PIP_EXTRA_ARGS="--no-index --find-links=./requirements/wheels"