When `/dev/kmsg` is unreadable due to sysctl value `kernel.dmesg_restrict=1`,
bind-mount `/dev/null` into `/dev/kmsg`
Fix issue 3011
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
Now rootless mode can be used with cgroup v2 resource limitations.
A pod is executed in a cgroup like "/user.slice/user-1001.slice/user@1001.service/k3s-rootless.service/kubepods/podd0eb6921-c81a-4214-b36c-d3b9bb212fac/63b5a253a1fd4627da16bfce9bec58d72144cf30fe833e0ca9a6d60ebf837475".
This is accomplished by running `kubelet` in a cgroup namespace, and enabling `cgroupfs` driver for the cgroup hierarchy delegated by systemd.
To enable cgroup v2 resource limitation, `k3s server --rootless` needs to be launched as `systemctl --user` service.
Please see the comment lines in `k3s-rootless.service` for the usage.
Running `k3s server --rootless` via a terminal is not supported.
When it really needs to be launched via a terminal, `systemd-run --user -p Delegate --tty` needs to be prepended to create a systemd scope.
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
Since a recent commit, rootless mode was failing with the following errors:
```
E0122 22:59:47.615567 21 kuberuntime_manager.go:755] createPodSandbox for pod "helm-install-traefik-wf8lc_kube-system(9de0a1b2-e2a2-4ea5-8fb6-22c9272a182f)" failed: rpc error: code = Unknown desc = failed to create network namespace for sandbox "285ab835609387f82d304bac1fefa5fb2a6c49a542a9921995d0c35d33c683d5": failed to setup netns: open /var/run/netns/cni-c628a228-651e-e03e-d27d-bb5e87281846: permission denied
...
E0122 23:31:34.027814 21 pod_workers.go:191] Error syncing pod 1a77d21f-ff3d-4475-9749-224229ddc31a ("coredns-854c77959c-w4d7g_kube-system(1a77d21f-ff3d-4475-9749-224229ddc31a)"), skipping: failed to "CreatePodSandbox" for "coredns-854c77959c-w4d7g_kube-system(1a77d21f-ff3d-4475-9749-224229ddc31a)" with CreatePodSandboxError: "CreatePodSandbox for pod \"coredns-854c77959c-w4d7g_kube-system(1a77d21f-ff3d-4475-9749-224229ddc31a)\" failed: rpc error: code = Unknown desc = failed to create containerd task: io.containerd.runc.v2: create new shim socket: listen unix /run/containerd/s/8f0e40e11a69738407f1ebaf31ced3f08c29bb62022058813314fb004f93c422: bind: permission denied\n: exit status 1: unknown"
```
Remove symlinks to /run/{netns,containerd} so that rootless mode can create their own /run/{netns,containerd}.
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
k3s was unable to start up when /var/lib/cni is missing on the host.
Fix https://github.com/rancher/k3s/issues/470
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
