Kubernetes is deprecating Docker as a container runtime after v1.20. This post shows how to install kubernetes on ubuntu 18.04 using containerd as a container runtime. For brevity, we do this just only on one node.
Below is a clean machine snap where we don't have docker installed.
We grab the 'cri-containerd-cni' package from https://storage.googleapis.com/cri-containerd-release and unpack it to the root directory:
Start containerd:
Next we follow the usual steps for installing kubernetes components from kubernetes documentation page:
lsmod | grep br_netfilter
modprobe br_netfilter
sysctl -w net.ipv4.ip_forward=1
[Service]
Environment="KUBELET_EXTRA_ARGS=--container-runtime=remote --runtime-request-timeout=15m --container-runtime-endpoint=unix:///run/containerd/containerd.sock"After this we run kubeadm init
We see that our control plane is up:
Deploy weave cni plugin:
kubectl apply -f "https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version | base64 | tr -d '\n')"
Untaint the master node so that we can deploy a pod on it since we have only one node:
kubectl taint node k8s-containerd node-role.kubernetes.io/master:NoSchedule-
There you go - migrate to containerd from docker for kubernetes.