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>
Fix issue 900
cgroup2 support was introduced in PR 2584, but got broken in f3de60ff31
It was failing with "F1210 19:13:37.305388 4955 server.go:181] cannot set feature gate SupportPodPidsLimit to false, feature is locked to true"
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
The containerd flag was accidentally added to kubelet and is
deprecated, but needed for cadvisor to properly connect with
the k3s containerd socket, so adding for now.
On my environment, the name=systemd entry in /proc/self/cgroup
looks like:
13:name=systemd:/docker/917b388b40c70b17a3283d852d38bfcdc84d1bf8242e32a779eacd98a610e499
Kubelet periodically complains like:
E0802 06:42:52.667123 1 summary_sys_containers.go:47] Failed to get system container stats for "/docker/917b388b40c70b17a3283d852d38bfcdc84d1bf8242e32a779eacd98a610e499/kube-proxy": failed to get cgroup stats for "/docker/917b388b40c70b17a3283d852d38bfcdc84d1bf8242e32a779eacd98a610e499/kube-proxy": failed to get container info for "/docker/917b388b40c70b17a3283d852d38bfcdc84d1bf8242e32a779eacd98a610e499/kube-proxy": unknown container "/docker/917b388b40c70b17a3283d852d38bfcdc84d1bf8242e32a779eacd98a610e499/kube-proxy"
Allow the kubelet resolv-conf flag to be set, or automatically
discovered from /etc/resolv.conf & /run/systemd/resolve/resolv.conf if
no loopback devices are present, or create our own which points to
nameserver 8.8.8.8
Akihiro Suda