I am moving from docker to podman and selinux because I thought that podman is more secure and hence, the future. I thought the transition will be somewhat seamless. I even prepaired containers but once I migrated I still ran into issues.
minor issue: it’s podman-compose instead of podman compose. The hyphen feels like a step back because we moved from docker-compose to docker compose. But thT’s not a real issue.
podman does not autostart containers after boot. You have to manually start them, or write a start script. Or create a systemd unit for each of them.
Spinning up fresh services works most of the time but using old services that worked great with docker are a pain. I am wasting minutes after minutes because I struggle with permissions and other weird issues.
podman can’t use lower number ports such that you have to map the ports outside of the machine and forward them properly.
Documentation and tutorials are “all” for docker. Github issues are “all” for docker. There isn’t a lot of information floating around.
I’m still not done and I really wonder why I should move forward and not go back to docker. Painful experience so far. https://linuxhandbook.com/docker-vs-podman/ and following pages helped me a lot to get rid of my frustration with podman.
Your issues stem from going rootless. Podman Compose creates rootless containers and that may or may not be what you want. A lot more configuration needs to be done to get rootless containers working well for persistent services that use low ports, like enabling linger for specific users or enabling low ports for non-root users.
If you want the traditional Docker experience (which is rootful) and figure out the migration towards rootless later, I’d recommend the following:
- Install
podman-docker. This provides a seamless Docker compatibility layer for podman, allowing you to even use regular docker commands that get translated behind the scenes into Podman. - Install regular
docker-compose. This will work viapodman-dockerand gives you the native docker compose experience. - Enable
podman.socketandpodman-restart.service. First one socket-activates the central Podman daemon, second one restarts any podman containers with arestart-policyofalwayson boot. - Run your docker-compose commands using
sudo, sosudo docker-compose up -detc. You can run this withsudo podman composeas well if you’re allergic to hyphenation. Podman allows both rootful and rootless containers and the way you choose is by running the commands withsudoor not.
This gets you to a very Docker-like experience and is what I am currently using to host my services. I do plan on getting familiar with rootless and systemd services and Kubernetes files, but I honestly haven’t had the time to figure all that out yet.
Enable podman.socket and podman-restart.service. First one socket-activates the central Podman daemon, second one restarts any podman containers with a restart-policy of always on boot.
Thanks, the last time I checked I was told that creating individual systemd services was the only viable solution and I ended up ditching podman because I didn’t think it was worth the hassle. I might try it again with your tips.
Definitely not necessary. If that was the case, it wouldn’t live up to it’s claims of being a transparent Docker replacement at all. I think you do need to use systemd if you want to go full rootless, but I haven’t tried it enough to make a solid call on that.
But yeah, with the above steps, I’ve moved seamlessly over to Podman for my self hosting stack and I’ve never looked back. It’s also great because I can take literally any Docker Compose I find on the Internet and it will most likely just work.
Podman is purposefully built to rely on systemd for running containers at startup. It ties in with the daemonless and rootless conventions. It’s also nice because systemd is already highly integrated with the rest of the OS, so doing things like making a container start up after a drive is mounted is trivial.
Podman has a command to generate systemd files for your containers, which you can then use immediately or make some minor tweaks to your liking.
I use podman for my homelab and enjoy it. I like the extra security and that it relies on standard linux systems like systemd and user permissions. It forces me to learn more about linux and things that apply to more than just podman. You can avoid a lot of trouble by running the containers as root and using network=host, but that takes away security and the fun of learning.
Regarding the low port number thing, that’s just a consequence of not running as root. By default, regular users can’t listen on ports below 1000.
Well hard drive manufacturers are actually correct. A gigabyte (GB) is in base 10 and thus 1000 megabytes, not 1024. Gibibytes (GiB) are base 2 (hence “bi”) and thus 1024 mebibytes.
Writing systemd services for your containers is something yoully have to get used to with podman, pretty much. It’s actually very easy with the built in command “podman generate systemd”, so you can just do something like " podman generate systemd --name my-container > /etc/systemd/system". I much prefer managing my containers with systemd over the docker daemon. It’s nice!
Also, podman can use privileged ports as root, right?
minor issue: it’s podman-compose instead of podman compose. The hyphen feels like a step back because we moved from docker-compose to docker compose. But thT’s not a real issue.
podman does not autostart containers after boot. You have to manually start them, or write a start script. Or create a systemd unit for each of them.
I’m also currently migrating all of my self-hosted services from docker to podman. Look into using Quadlet and systemd rather than podman-compose: https://www.redhat.com/sysadmin/quadlet-podman
Your Quadlet .container files will end up looking very similar to your docker compose files. Podman will automatically generate a systemd service unit for you if you drop the .container file in your user systemd unit directory ($HOME/.config/containers/systemd/) and run systemctl --user daemon-reload. Then starting the container on boot is as simple as systemctl --user enable --now containername.service.
This will not solve your rootful vs. rootless issues, as others have pointed out, but Quadlet/systemd is nice replacement for the service/container management layer instead of docker-compose/podman-compose
