FOSS

Let’s say that we want to keep our system updated with some code which is not distributed as a regular package, but as a code in a repository (which unfortunately, it’s a pretty common situation). As a part of the ansible playbooks used for the hosts, I can add a snippet like this: gitrepos: - { url: "https://github.com/myrepo/repo.git", tag: "tagtocheckout", folder: "/root/path-for-check-out", chdir: "subdir to enter", build: "make build", exec: "build/mybuiltbinary", } With this definition in the host inventory, we can then in our playbook to perform several steps: ...

A colleague reported some issues in the OpenShift troubleshooting and diagnosis scripts at OpenShift-checks. Some time ago I did contribute some changes to use functions and allow using the RISU wrapper to the scripts, helping consuming the results via RISU’s HTML interface. As my colleague reported, for some plugins, the output of the command was not shown in the HTML Interface. After some investigation, it was found that parallel execution for the plugins was causing no output to be shown, but when filtering to individual ones via risu -i XXXXXXX/plugin -l it was working fine… the problem was not the check itself, as both of them worked fine when executed individually but failed when executing them together. ...

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. ...

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: ...

I did the RHCE exam some time ago, and still there are some tricks and advices I tell the people to bear in mind some of the things I used and that were also provided in the Red Hat Enterprise 8 Administration book: Don’t remember every step, it’s not effective, for example as I don’t recall syntax for BIND, I do remember package that has some files with examples and I use that one to check what I need to do Install mlocate and run updatedb as soon as you start, then you can use locate <file> to find out files in your system Use your preferred editor… it’s common to use vi or vim as it’s pretty standard, but if you’re used to another, make yourself comfortable in the system. As one instructor like to say: “Anyone with unlimited amount of time will be able to pass the exam”. RHCE is a performance-based exam, that means that you need to cover all the required goals within the exam duration, and in the end, the goals is to accomplish, not to do in the smarter way. For example, if you’re told to configure resolv.conf you can either use nmcli to modify the settings or you can pipe the results to it via echo nameserver 1.1.1.1 > /etc/resolv.conf, in the end, both will have the same effect, and of course, using nmcli will be smarter when you’re keeping multiple systems and using automation… but for the exam, the goal is to focus on the fastest path to master at it. You can find more tricks at Red Hat Enterprise 8 Administration Enjoy! (and if you do, you can Buy Me a Coffee ) ...