Red Hat is proud to announce that Ansible supports managing Red Hat Enterprise Linux 8 Beta hosts. Before you can manage Red Hat Enterprise Linux 8 Beta nodes with Ansible 2.7, though, you need to set the appropriate python interpreter. Ansible allows you to manage a huge range of hosts and devices, from legacy systems to beta-release testing platforms, by working with both Python 2 and Python 3. However, with Ansible 2.7 managing Red Hat Enterprise Linux 8 Beta, you must define which Python to use. When Ansible 2.8 is released, we plan for Ansible to automatically discover the correct Python to use on Red Hat Enterprise Linux 8 Beta hosts.
Setting the Python interpreter on Red Hat Enterprise Linux 8 Beta managed nodes
You can define the python interpreter Ansible should use on your Red Hat Enterprise Linux 8 Beta nodes with an inventory host_var, a group_var, a play, or an ad-hoc command. You must do this on every Red Hat Enterprise Linux 8 node just as you would for any Python3 enabled host. To set the python interpreter in your inventory with a host_var:
[RHEL8hosts] RHEL8.example.com ansible_python_interpreter=/usr/libexec/platform-python
This example directs Ansible to use the Red Hat Enterprise Linux 8 Platform Python, which is meant for systems-level tooling, rather than the standard python interpreter. Since Ansible will be automating systems-level tasks, this will be our target.
Once you’ve set the correct python interpreter, you can run Ansible to manage this Red Hat Enterprise Linux 8 Beta system:
ansible RHEL8hosts -m yum -a “name=bash state=installed”
In Ansible 2.8, Ansible will automatically discover the best ansible_python_interpreter definition, and you will not need to set the python interpreter like this.
Testing Red Hat Enterprise Linux 8 Beta as an Ansible control node
Ansible Engine does not support using a Red Hat Enterprise Linux 8 Beta system as a control node in a production setting. However, you may wish to test this scenario locally to prepare for the eventual Red Hat Enterprise Linux 8 GA release. Note that Red Hat Ansible Engine is planning to support Red Hat Enterprise Linux 8 upon Ansible Engine 2.8 GA release, but at this time we’ll be using the upstream Ansible open source project to test our Red Hat Enterprise Linux 8 Beta control node.
Do not use the system-level Red Hat Enterprise Linux 8 Platform Python for control node actions. Instead, install a user-level Python to run Ansible commands, roles, and playbooks from a Red Hat Enterprise Linux 8 Beta system. We recommend installing Python 3.6 from an Ansible Upstream Project package via PyPI.
On the Red Hat Enterprise Linux 8 Beta host you plan to test as a control node, run the following command either as root or with sudo permissions:
yum -y module install python36
This command installs the Python 3.6 AppStream, which allows you to operate on the same version of Python as Platform Python but in a user-facing context. This is important for long-term compatibility but also for the flexibility to modify our environment without impacting the core Red Hat Enterprise Linux 8 Beta Platform.
Once you have Python 3.6 installed, install Ansible as a non-root user (recommended for installing PyPI content).
pip3 install --user ansible
Confirm that your Ansible installation is working with a quick test on localhost, using your Red Hat Enterprise Linux 8 Beta machine as both the control node and a managed node:
ansible localhost -m setup -e ansible_python_interpreter=/usr/libexec/platform-python
This ad-hoc command sets the ansible_python_interpreter on your Red Hat Enterprise Linux 8 Beta control node. At this point you can run Ansible on your Red Hat Enterprise Linux 8 Beta system just as you normally would from a standard install using pip.
When testing a Red Hat Enterprise Linux 8 Beta system as an Ansible control node and running against localhost, you use two different Python executables: the Python 3.6 package with Ansible Engine and the Platform Python with the modules kicked off by your ad-hoc task or playbook.
What Next? Questions? Comments? Feedback?
The Ansible Open Source Community is adapting to the release of Red Hat Enterprise Linux 8 Beta in the open, just as we do with all changes in technology. If you have questions, comments, or feedback about Ansible + Red Hat Enterprise Linux 8 Beta or anything else that interests you, we’d love to hear from you.
Originally posted on Ansible Blog
Author: Adam Miller