I use podman, even when I started out. But I am a tinkerer. I think for the average beginner, docker will be easier as so much out there assumes you are using Docker only, and hard codes it. Unless you wanna deal with that, use Docker.
Docker. It’s been around longer, it’s more polished, easier to learn, simpler to use, supported everywhere and by everything, easy to find solutions when you search for help, doesn’t depend on systemd, compatible with every container image out there, and you can do things with it even if it’s not the “correct” way to do it while podman will tell you “no, you can’t do that”.
I’d go Docker for the maturity. Podman is nice but I’ve definitely had some issues, and Buildah lacks any sort of caching and does unnecessary intermediate copies of the layers when pushing to a repository that really slows things down on larger apps/images.
If your distro offers it, rootless podman + podman system service is the best setup, IMO. That will give you a
docker
command that is 1-to-1 compatible with docker and lets you use tools like docker-compose that expect a docker service socket. Then you can just follow tutorials that only explain things for docker.What is rootless bring brought up so much? It’s a container, it’s isolated from the host anyway, what does it matter what user runs inside? And if something breaks into the container they can trash the app in it and the shared volumes anyway, even if they’re not root.
Because a container is only as isolated from the host as you want it to be.
Suppose you run a container and mount the entire filesystem into it. If that container is running as root, it can then read and write anything it likes (including password databases and /etc/sudo)
So what? If I mount / in the container and choose to run it as root that’s my business. Why would the containerization engine second-guess what I’m doing?
How would you like it if sudo told you “I can’t let you be root, you could read and write anything you like, including password databases and /etc/sudo”?
The point is to minimize privilege to the least possible - not to make it impossible to create higher privileged containers. If a container doesn’t need to get direct raw hardware access, manage low ports on the host network, etc. then why should I give it root and let it be able to do those things? Mapping it to a user, controlling what resources it has access to, and restricting it’s capabilities means that in the event that my container gets compromised, my entire host isn’t necessarily screwed.
We’re not saying “sudo shouldn’t be able to run as root” but that “by default things shouldn’t be run with sudo - and you need a compelling reason to swap over when you do”
It depends on the use case. The most common security issue I have seen with docker is on Linux desktop systems: docker deamon runs as root and user wants to use it to test all kinds of containers. So they make the docker socket accessible to the user, to lazy to use “sudo docker” every time… Having access to the docker socket means having the same permissions as the one running the daemon: root . Your browser effectively now has root permissions. At this point you could just login as root to your desktop.
Defense in depth. If something escapes the container it’s limited to only what’s under that user and not the whole system. Having access to the whole system makes it easier for malware to hide/persist itself.
Correct me if I’m wrong but containerization is enforced by the kernel, correct? If something escapes you’re pretty much screwed anyway.
There are many layers involved in preventing escapes from containers.
Docker because it just works. Podman has another 5 years (hopefully) to get this part right IMO.
On what host system?
Don’t overthink this. Just start using something.
Podman, rootless containers work well, and there is no central process running everything. I like that starting containers on boot is integrated with systemd.
i would like to try… but as far as i know, there is no “docker compose up -d”
Apparently it does! podman-compose
cool, thank you!
Check my comment history for an example of a simple bind mount
compose.yaml
I use for developing a small Python project. It’s exactly the same as Docker Compose (since Podman Compose follows the Compose spec) but if you’re just getting started, it might be a good skeleton to build on.i have all my stacks on docker compose. if it follows the same specks, i would only need to convert volumes and networks
Podman supports docker compose just fine. You have to run it as a service, so that it can expose a socket like docker does, but it supports doing exactly that