Podman
The following table shows the feature implementation status of Rootless Podman:
Version | Notable changes |
---|---|
Pre-1.1 | Initial support for Rootless mode |
1.1 | Added support for port forwarding (podman run -p ) |
1.5 | Added support for cgroup v2 |
2.1 | Added support for multi-container networking (podman create network ) |
FAQ: Docker/Moby vs Podman?
Until recently, Docker/Moby had lacked support for cgroup v2, and on the other hand Podman had lacked support for multi-container networking.
As of October 2020, the two projects implement almost the same features with regard to the support for Rootless mode.
Note
Please read the common steps first.
The easiest way to install Rootless Podman is to install podman
package.
Requires sudo
.
$ sudo apt-get install -y podman
$ sudo dnf install -y podman
Rootless Podman could also be installed without sudo
in theory.
However, as of October 2020, there is no official Podman binaries that can be installed
without sudo
.
Just run podman
command.
$ podman run docker.io/library/hello-world
Resource-related flags of podman run
, such as --cpus
, --memory
, --blkio-weight
, and --pids-limit
can be used only when the following conditions are satisfied:
- Podman version is 1.5 later
- runc version is 1.0-rc91 or later, or crun is installed
- The host is running with cgroup v2
- The host is running with systemd
To impose resource limitations without cgroup, see https://docs.docker.com/engine/security/rootless/#limiting-resources (read docker
as podman
)
Podman uses RootlessKit as the default port forwarder.
However, as explained in How it works, sometimes slirp4netns port forwarder is preferred over RootlessKit port forwarder.
To change the port forwarder to slirp4netns, run podman run
with --network slirp4netns:port_handler=slirp4netns
.
See also http://docs.podman.io/en/latest/markdown/podman-run.1.html
As Podman lacks the central daemon, you need to create systemd unit files to launch the each of the containers on the system startup.
See http://docs.podman.io/en/latest/markdown/podman-generate-systemd.1.html
Also, you need to run sudo loginctl enable-linger ...
. See Getting Started/Login.
Run the following commands to remove all containers and configurations:
$ podman system reset
The command might not be available with very old podman versions. For old releases, run the following commands instead:
$ podman rm -f $(podman ps -a -q)
$ podman unshare rm -rf ~/.local/share/containers ~/.config/containers
To uninstall binaries, remove podman
package with the package manager.
See https://github.com/containers/podman/blob/master/docs/tutorials/rootless_tutorial.md