Operators on OpenShift

OpenShift provides an Operators section in its web console UI for the installation and management of operators on the cluster. OperatorHub The OperatorHub is an interface for searching and installing operators. It has the following categories of operators: Red Hat Operators: Operators developed and supported by Red Hat. Example: Red Hat Quay Operator Certified Operators: Operators listed by Red Hat’s Independent Software Vendors (ISVs). Example: CockroachDB Operator Red Hat Marketplace Operators: Applications purchased from Red Hat Marketplace available as Operators....

May 3, 2023 · 4 min · Avnish

Kubernetes Operators

Applications built to be deployed on Kubernetes could be packaged as Operators. Operators automate the process of installation, updates, and management of the application. These automations are defined by developers based on the application’s business logic. An Operator consists of: Custom Resources (CRs) required by the application Custom controller for managing these CRs Control Loop A control loop is an infinite loop for monitoring the state of a system....

May 1, 2023 · 4 min · Avnish
Building container images from Containerfile

Building Container Images

Public registries provide container images for most use cases but they might not cover all of them. That’s why container engines such as Podman & Docker and CLI tools like buildah provide utilities for creating custom container images. The build steps are written in a plaintext file called Containerfile and parsed by container engines (or buildah) during the build process. # ContainerfileFROMnode:18-alpineLABEL version="1.0" WORKDIR/appCOPY . .RUN yarn install --productionCMD ["node", "src/index....

March 20, 2023 · 5 min · Avnish
Workflow of container images

Container Images

A container image is a static file that contains the necessary resources (packages, configuration, other dependencies) required to provision a container. It consists of multiple layered-filesystems and a Manifest file, containing its metadata. Open Container Initiative (OCI) Specification Open Container Initiative was established by The Linux Foundation in 2015 to provide Runtime specification Image specification Distribution specification for container images. A container image created from OCI Image specification should have...

March 17, 2023 · 5 min · Avnish
Lifecycle of a container

Container Lifecycle

Container Engines like Podman and Docker provide GUI and CLI utilities for managing the state of containers. They also provide features such as container image management, metrics, logging, and debugging tools. The examples in this article use Podman but CLI commands are mostly interoperable with Docker. We can install Podman on your system by following the steps in Podman Installation Instructions. Podman also provides a graphical interface for managing containers, images, and other resources called Podman Desktop....

February 10, 2023 · 6 min · Avnish