Rocky Mountains, Maple Ridge BC — Lawrence Manickam

Podman — A Dockerless Container Engine — Part I

Few IT decision makers want to remove their dependency on Docker. It is evident and happening.

Docker is the monopoly in the Container Market and the Docker CE tool does not have a commercial support model. Therefore, companies such as Red Hat encourage Buildah, Podman and Skopeo for Container Management with Kubernetes (Red Hat OpenShift).

A Docker environment has the following challenges;

The industry needs a Container engine that is daemonless and rootless. Here’s the Podman;

Podmn.io defines ‘Podman is a daemonless container engine for developing, managing, and running OCI Containers on your Linux System. Containers can either be run as root or in rootless mode.’.

Features;

In this article, I provide a run book for how to install Podman and operate Containers at CentOS 8.

Login as root

Check Docker

See, there is no Docker.

Install Podman and Slirp4netns

Increase user namespaces

Configure subuid and subgid values

Update registries

The default registries.conf under /etc/container has entries to access few registries including docker.io (Public Docker Hub). I edit this file to use Public Docker Hub.

Login in as rootless user (kuberiter)

Log in directly as the rootless user ‘kuberiter’ (Don’t use su or su — to become that user because that doesn’t set the correct environment variables).

Check rootless configuration

To check that your rootless configuration is set up properly, you can run commands with the podman unshare command.

Pull an Image

List Images

Start the Container

Display running Containers

Information about a Container

Stop the Container

Remove the Container

Container Storage — rootless user

Podman stores containers under the home directory of the rootless user.

Limitations of Podman

Watch the Podman demo Video here.

In the next article, I will write about Buildah and Skopeo.

Lawrence Manickam is the Founder of Kuberiter Inc, a Seattle based Start-up that provide Enterprise/SaaS DevOps Services (Kubernetes, Docker, Helm, Istio and CyberArk Conjur) for MultiCloud.

Please subscribe at www.kuberiter.com to try our DevOps SaaS Services.