Historically, Docker Engine or Docker has always required root privileges to run. This is because certain features like namespaces or mount points which forms the basis of Docker filesystems have always required elevated privileges. You may have started running docker daemon or dockerd in context of another user, but that user needs to be made part of Docker Group, which was assigned root privileges during installation time. Rootless mode means running the Docker daemon and even containers as an unprivileged user to protect the root user from future attacks on the host system.Read More »
In the Kubernetes release v1.20, the development team has marked dockershim as deprecated. There was initially some shock and confusion, as it was perceived that team is moving away from docker completely, however that is not the case. As its turns out, what the team is doing, is steering the Kubernetes away from the proprietary parts of Docker or Docker Engine or just simply called Docker. The Docker Engine is further comprised of many different sub-components like dockerd, containerd, runc etc., many of which were initially developed by Docker Inc and then given away to community. These were later standardized and maintained by the community.
The Kubernetes community has written a detailed blog post about deprecation with a dedicated FAQ page for it. This blog post is being written to understand the impact and what needs to be done about it. Depending on how do you use Docker, think and understand about it, you may or may not have to do anything about it or get worried about sleepless nights.Read More »
Podman is a daemonless container engine for developing, managing, and running Open Container Initiative (OCI) containers and container images on your Linux System. It is an open-source project that is available on most Linux platforms and resides on GitHub. Containers under the control of Podman can either be run by root or by a non-privileged user. Podman provides a docker engine compatible command interface and most of the commands can simply be used by
alias docker=podman for experience professionals on docker. However, that said, Podman is not a replacement of dockerd, docker compose and docker swarm yet. In this post, we’ll learn the basic operations with Podman as container engine.
A docker image registry is used to store docker images and maintain their versions. Container runtime engines such as Podman, Containerd, CRI-O, rkt, etc are typically used to the push and pull images using their respective commands. Most of these runtimes have a way to create and maintain a local registry for the machine on which they are installed. However when sharing images between different machines, we need a centralized repository where one can push and pull images. There are lot of PaaS registry services are available in the market already. However, sometimes you may want to have your own personal/private registry where you can control what images are available for your runtimes.Read More »