OpenShift

With recent releases of OpenShift like 4.13 you can use CoreOS Layering to apply custom images to the nodes. The feature allows to build, via a Dockerfile a custom image that can later be applied to our nodes. Let’s review the steps: First we need to find the base image being used in our environment with oc adm release info quay.io/openshift-release-dev/ocp-release:4.13.5-aarch64 --image-for=rhel-coreos Then we use the returned value in the FROM line in our Dockerfile If we want to add custom packages, we should have a server which is reachable and run createrepo on the folder containing the rpm’s so that rpm-ostree can download them for installation. Example dockerfile: ...

Following on the Using Kcli to prepare for OCM testing, we’re going to prepare KMM testing in Hub-Spoke approach. First we need to prepare our .docker/config.json with the contents of our OpenShift pull secret used with Kcli. mkdir -p ~/.docker/ cp openshift_pull.json ~/.docker/config.json Warning advisories Note Semi-scripted version available at automate.sh Warning We’re using pre-release bits of the software, that’s why we need to define a custom catalog for both the Hub and the Spokes. Once KMM is released it will be available from the official one and just the Policy will be needed. ...

Kcli allows to quickly interact with different virtualization platforms to build machines with some specific configurations, and via the use of plans it allows to automate most of the setup required to have an environment ready. In our case, let’s setup an environment to practice with Open Cluster Management but instead of using kind clusters, let’s use VM’s. Note We’ll require to setup an openshift_pull.json file for Kcli to consume when accessing the required resources for this to work. That file, contains the credentials for accessing several container registries used for the deployment. ...

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. ...

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: ...