podman VS nerdctl

Example of why: https://github.com/containers/podman/issues/5102#issuecommen...

Podman

Even though we will focus on Docker for this article, I wanted to mention that there are more container creation and management tools such as Podman, Rkt, and so on.

By using containerization, the application will always have the same configuration that is used in the development environment and production environment. There is no more "It works on my machine". Some examples of containerization technologies are Docker and Podman.

Podman Documentation. Podman is a daemonless container engine for developing, managing, and running OCI Containers on your Linux System.

AFAIK podman either already supports pods in quadlet container files, or will in the near future. https://github.com/containers/podman/pull/20762

Podman as a devcontainers engine doesn't currently work if you use devcontainer features [1] or (and this sounds like you're issue) if you use WSL2.

I haven't submitted the WSL2 issue to the Podman team yet. If you get to it before I do, can you like it here?

https://github.com/containers/podman/issues/18691#issuecomme...

You can also use their Oracle Linux Docker images with the database preinstalled using either Podman or Docker. Just make absolutely sure you are downloading something you are licensed to use, because it seems really easy to accidentally infringe copyright via this method.

It's an open source project. https://github.com/containers/podman and https://podman.io - go there, get engaged, see what's going on and most important become part of the community and contribute!

Direct use of containerd? containerd? turns out I didn't know anything about container technology. containerd was originally developed by Docker in 2015 as a daemon that provided basic container management capabilities under Docker. containerd's scope has gradually expanded and now seems to cover almost everything in the Docker Engine. For example, nerdctl is a CLI for containerd; the UX is almost identical to the Docker CLI, and Docker Compose is also supported (nerdctl compose).

Nerdctl[1] (for containerd) works fine with docker-compose.yml for my purposes (which are not much). The only issue I encountered was with environment variable substitution not working the same as docker-compose, but I didn't look hard for a solution and edited my compose file

1. https://github.com/containerd/nerdctl mine came bundled with Rancher desktop, and 'nerdctl compose up' is all I've needed

I haven't tried it personally but you might be able to export the tar from docker host with docker cli and then load it on containerd host using nerdctl - https://github.com/containerd/nerdctl

It looks like the real nice thing here is having a formula for QEMU with the ARM patch applied: https://github.com/simnalamburt/qemu/tree/hvf

With this I believe you could also used [nerd](https://github.com/containerd/nerdctl) instead of podman but I haven't tested it yet.

One area, where containerd didn't had a first class support was CLI. the default containerd CLI "ctr" has a very naive implementation. The reason for that I believe is, containerd as a system was never meant to be consumed by humans, and was designed to be consumed by higher layers e.g. orchestration systems like nomad or k8s. However, with the deprecation of dockershim in k8s, and users moving to containerd, a new docker compatible CLI came out:

https://github.com/AkihiroSuda/nerdctl

If you just have containerd running on your system (with no docker daemon running), you can just install nerdctl and add

alias docker="nerdctl"

to your ~/.bashrc file.

Then you can just run any docker commands the way you used to with docker, and it will run those commands against the containerd API giving you the same CLI experience that you used to have with docker.