Last year, together with my colleagues Miguel and Scott, we released with the help of Packt team the RHEL8 Administration. During this one, with the collaboration of Pedro, a long-time colleague from the University LUG, we worked on the updated Red Hat Enterprise Linux 9 Administration book that it’s now available for preorder on Amazon. As with the previous version, the book targets users willing to learn skills to administer Red Hat Enterprise Linux or compatible systems. It is a hands-on guide to the administration and can be used as reference thanks to the real-life examples provided along the text. ...

For my ansible playbooks, I wanted to be able to add several new templates to be copied to target system, and additionally be able to perform some commands for them without having to specify each individual file/template to copy. My approach: Define for the hosts I want to find templates/playbooks define a var named extras for the relevant hosts: extras: - ntp - certificates The names defined (in above example ntp and certificates) are just name of folders laying inside tasks/templates/${folder} that are searched and included or excluded based on extras values. ...

Use sorted list for included files vs random provided by with_fileglob. - name: Include tasks include_tasks: "{{item}}" loop: "{{ query('fileglob', 'tasks/*.yaml') | sort }}"

In order to setup disconnected registry for installation, follow this blog post by Daniel at Introducing Mirror Registry for Red Hat OpenShift. At the end of the process it will output something like: INFO[2022-08-19 07:10:22] Quay installed successfully, permanent data is stored in /etc/quay-install INFO[2022-08-19 07:10:22] Quay is available at https://${HOSTNAME}:8443 with credentials (init, ${PASSWORDSTRING}) Once the setup is done, remember several steps: Edit /etc/containers/registries.conf to add relevant entries for our registry as required: ...

Check agent status per state watch -d "oc get agent -A -o jsonpath='{range .items[*]}{@.status.debugInfo.state}{\"\n\"}{end}' |sort | uniq --count"