cri-o VS jib

Kubernetes on the backend used to utilize docker for much of its container runtime solutions. One of the modular features of Kubernetes is the ability to utilize a Container Runtime Interface or CRI. The problem was that Docker didn't really meet the spec properly and they had to maintain a shim to translate properly. Instead users could utilize the popular containerd or cri-o runtimes. These follow the Open Container Initiative or OCI's guidelines on container formats.

Multiple container runtimes are supported, like conatinerd, cri-o, or other CRI compliant runtimes.

Install container runtime on all nodes. We will use cri-o.

Container Runtime Interface (CRI) is one of the important parts of the Kubernetes cluster. It is a plugin interface allowing kubelet to use different container runtimes. And recently CRI-O container runtime has been announced as a CNCF Graduated project. I thought of writing a blog on CRI-O and how to set up a single-node Kubernetes cluster with Kubeadm and CRI-O.

CRI-O: This is an open-source container runtime designed for use with Kubernetes. It is a lightweight and stable environment for containers. It also complies with the Kubernetes Container Runtime Interface (CRI), making it easy to integrate with Kubernetes.

With CRI-O I believe you can configure registry mirror locations…. Similar to this: https://github.com/cri-o/cri-o/issues/4941

Alternatives like Podman and CRI-O continue to gain traction and may replace Docker in various places. For example, Kubernetes used to use Docker, then moved to containerd, and now also support CRI-O. Generally speaking, the core features of "Docker" are such a commodity now that no one was the wiser when Kubernetes stopped using it.

will the site be available for the CKA exam? https://github.com/cri-o/cri-o/blob/main/install.md

The CRI-O container engine provides a stable, more secure, and performant platform for running Open Container Initiative (OCI) compatible runtimes. CRI-Os purpose is to be the container engine that implements the Kubernetes Container Runtime Interface (CRI) for OpenShift Container Platform and Kubernetes, replacing the Docker service. Source

You need to build Docker images for each app. This is specific to the JHipster application used in this tutorial which uses Jib to build the images. Make sure you are logged into Docker using docker login. Navigate to each app folder (store, invoice, product) and run the following command:

JIB

It is pretty easy to do with https://github.com/GoogleContainerTools/jib.

Save yourself the dockerfile and use jib: https://github.com/GoogleContainerTools/jib/tree/master/jib-maven-plugin

I first learned about Distroless because it was the default option in Google's Jib. Jib is a Maven plugin to create Docker containers without dependency on Docker. Note that the default has changed now.

Optimize your Dockerfile by using a small base Java Image, use either Spring Boot's layers tools or Google Jib to build your docker file, and increase CPU/Memory requests and limits if you can.

In this section, we will setup the automated generation and deployment of a Docker container image. You will need a Docker Hub account and the Jib Gradle Plugin.

If you don't want to hack on your own scripts to package your app into a container, I can recommend the JIB maven plugin. A gradle version is also available.