[Podman] Re: podman and kubernetes

Minikube supports using "sudo podman" to run minikube in a privileged container, as an alternative to "docker". And it also supports using cri-o / podman as an alternative to containerd / buildkitd, replacing the old "rkt". Previously we defaulted to VirtualBox, but now the default is Docker. It has some better support for Mac and Win. The container runtime default is still Docker and "dockershim", but this will move to use CRI and "cri-dockerd". https://minikube.sigs.k8s.io/docs/drivers/podman/ Podman is supported on Linux, but not on Mac or Win: https://github.com/kubernetes/minikube/issues/8003 Minikube also supports using the VM as an alternative to starting another VM with Docker Desktop or Docker Machine. Here were are using the "podman-env" command to do it for Podman, which works similar to the "docker-env" command.: https://minikube.sigs.k8s.io/docs/commands/podman-env/ It uses the podman-remote client, installed on the host. (disguising as "podman" on Mac and on Win, confusingly) The main issues are the recurring regressions and the lack of testing (especially in CI). They might be related ? As you have noted, most of the users and most of the k8s documentation is running Docker and running on Ubuntu. But both CRI-O and Fedora have been supported for years, even if they might be unavailable due to technical issues. For instance: upgrading to cgroups v2, changing from varlink to rest, changing to btrfs, or Next Big Thing etc Kubernetes documentation is handled by a separate SIG, but they are _also_ accepting PRs to improve their docs. Running kubernetes in rootless podman (and docker) is something being *actively* worked on. Not there just yet. Most of it is handled in the "kind" project, sharing code with minikube: https://kind.sigs.k8s.io/docs/user/rootless/ So Podman can be used for *running* Kubernetes ("kinp"), and it can also be used on a node that is running Kubernetes. Currently we are using "podman build" for image building. There has been no reason to expose Buildah to the user. The benefit of this is that the images are immediately available to the k8s cluster. No registry, no waiting time. See https://minikube.sigs.k8s.io/docs/handbook/pushing/ for the actual minikube commands that are involved there. One uses "sudo crictl" for interfacing with containers. There are no podman commands used for that, only images. Docker and rkt are mentioned for historical reasons. Both have been used The rkt support has been removed, and dockershim will be removed. But Docker is still there. It will just be forced to use the same interfaces (CRI / CNI) as everybody else has to... I understand that the podman team is not in charge of that documentation, We are using podman as a _complement_ to cri-o, since they do share the same images... They do not share the same container instances though, and don't use the same code (yet) We are mostly using the Kubernetes Slack, where there is both #minikube and #crio Will also try to join the Podman Community meeting on Tuesday (June 1st), as usual. /Anders https://github.com/afbjorklund