7a962e9d1c
If DIB_PYTHON_VERSION is < 3 on the !redhat path, that means we're on an older platform that may not have python3-virtualenv packages. Skip install. Ensure the order of operations happens by forcing the installs Also add a note about limited platform support (patches welcome :) Change-Id: I18412767f0ebf946d557a0a126285369e96af159
76 lines
2.5 KiB
ReStructuredText
76 lines
2.5 KiB
ReStructuredText
==================
|
|
pip-and-virtualenv
|
|
==================
|
|
|
|
This element installs pip and virtualenv in the image.
|
|
|
|
Package install
|
|
===============
|
|
|
|
If the package installtype is used then these programs are installed
|
|
from distribution packages. In this case, ``pip`` and ``virtualenv``
|
|
will be installed *only* for the python version identified by
|
|
``dib-python`` (i.e. the default python for the platform).
|
|
|
|
Distribution packages have worked out name-spacing such that only
|
|
python2 or python3 owns common scripts like ``/usr/bin/pip`` (on most
|
|
platforms, ``pip`` refers to python2 pip, and ``pip3`` refers to
|
|
python3 pip, although some may choose the reverse).
|
|
|
|
To install pip and virtualenv from package::
|
|
|
|
export DIB_INSTALLTYPE_pip_and_virtualenv=package
|
|
|
|
Source install
|
|
==============
|
|
|
|
Source install is the default. If the source installtype is used,
|
|
``pip`` and ``virtualenv`` are installed from the latest upstream
|
|
releases.
|
|
|
|
Source installs from these tools are not name-spaced. It is
|
|
inconsistent across platforms if the first or last install gets to own
|
|
common scripts like ``/usr/bin/pip`` and ``virtualenv``.
|
|
|
|
To avoid inconsistency, we firstly install the packaged python 2
|
|
**and** 3 versions of ``pip`` and ``virtualenv``. This prevents a
|
|
later install of these distribution packages conflicting with the
|
|
source install. We then overwrite ``pip`` and ``virtualenv`` via
|
|
``get-pip.py`` and ``pip`` respectively.
|
|
|
|
The system will be left in the following state:
|
|
|
|
* ``/usr/bin/pip`` : python2 pip
|
|
* ``/usr/bin/pip2`` : python2 pip (same as prior)
|
|
* ``/usr/bin/pip3`` : python3 pip
|
|
* ``/usr/bin/virtualenv`` : python2 virtualenv
|
|
|
|
(note python3 ``virtualenv`` script is *not* installed, see below)
|
|
|
|
Source install is supported on limited platforms. See the code, but
|
|
this includes Ubuntu and RedHat platforms.
|
|
|
|
Using the tools
|
|
===============
|
|
|
|
Due to the essentially unsolvable problem of "who owns the script", it
|
|
is recommended to *not* call ``pip`` or ``virtualenv`` directly. You
|
|
can directly call them with the ``-m`` argument to the python
|
|
interpreter you wish to install with.
|
|
|
|
For example, to create a python3 environment do::
|
|
|
|
# python3 -m virtualenv myenv
|
|
# myenv/bin/pip install mytool
|
|
|
|
To install a python2 tool from pip::
|
|
|
|
# python2 -m pip install mytool
|
|
|
|
In this way, you can always know which interpreter is being used (and
|
|
affected by) the call.
|
|
|
|
Ordering
|
|
========
|
|
Any element that uses these commands must be designated as
|
|
05-* or higher to ensure that they are first installed.
|