7a6aeff403
There are no 5.* versions of ansible for CentOS 8 Stream yet. One should use pip install 'ansible>=4,<6' according to the current documentation. Closes-Bug: #1969617 Change-Id: Ie4f502f955dac5ae9ee8ddb4779c2fa2e26840d9
76 lines
2.6 KiB
ReStructuredText
76 lines
2.6 KiB
ReStructuredText
.. _virtual-environments:
|
|
|
|
====================
|
|
Virtual Environments
|
|
====================
|
|
|
|
Python `virtual environments <https://docs.python.org/3/library/venv.html>`_
|
|
provide a mechanism for isolating python packages from the system site packages
|
|
and other virtual environments. Kolla-ansible largely avoids this problem by
|
|
deploying services in Docker containers, however some python dependencies must
|
|
be installed both on the Ansible control host and the target hosts.
|
|
|
|
Kolla Ansible supports the default Python 3 versions provided by the
|
|
:kolla-ansible-doc:`supported Operating Systems <user/support-matrix>`. For
|
|
more information see `tested runtimes <|TESTED_RUNTIMES_GOVERNANCE_URL|>`_.
|
|
|
|
Ansible Control Host
|
|
====================
|
|
|
|
The kolla-ansible python package and its dependencies may be installed in a
|
|
python virtual environment on the Ansible control host. For example:
|
|
|
|
.. code-block:: console
|
|
|
|
python3 -m venv /path/to/venv
|
|
source /path/to/venv/bin/activate
|
|
pip install -U pip
|
|
pip install kolla-ansible
|
|
pip install 'ansible>=4,<6'
|
|
deactivate
|
|
|
|
To use the virtual environment, it should first be activated:
|
|
|
|
.. code-block:: console
|
|
|
|
source /path/to/venv/bin/activate
|
|
(venv) kolla-ansible --help
|
|
|
|
The virtual environment can be deactivated when necessary:
|
|
|
|
.. code-block:: console
|
|
|
|
(venv) deactivate
|
|
|
|
Note that the use of a virtual environment on the Ansible control host does not
|
|
imply that a virtual environment will be used for execution of Ansible modules
|
|
on the target hosts.
|
|
|
|
.. _virtual-environments-target-hosts:
|
|
|
|
Target Hosts
|
|
============
|
|
|
|
Ansible supports remote execution of modules in a python virtual environment
|
|
via the ``ansible_python_interpreter`` variable. This may be configured to be
|
|
the path to a python interpreter installed in a virtual environment. For
|
|
example:
|
|
|
|
.. code-block:: yaml
|
|
|
|
ansible_python_interpreter: /path/to/venv/bin/python
|
|
|
|
Note that ``ansible_python_interpreter`` cannot be templated.
|
|
|
|
Kolla-ansible provides support for creating a python virtual environment on the
|
|
target hosts as part of the ``bootstrap-servers`` command. The path to the
|
|
virtualenv is configured via the ``virtualenv`` variable, and access to
|
|
site-packages is controlled via ``virtualenv_site_packages``. Typically we
|
|
will need to enable use of system site-packages from within this virtualenv, to
|
|
support the use of modules such as yum, apt, and selinux, which are not
|
|
available on PyPI.
|
|
|
|
When executing kolla-ansible commands other than ``bootstrap-servers``, the
|
|
variable ``ansible_python_interpreter`` should be set to the python interpreter
|
|
installed in ``virtualenv``.
|