Changing the Container Runtime on a Node from Docker Engine to containerd [page]deterministic
This task outlines the steps needed to update your container runtime to containerd from Docker. It is applicable for cluster operators running Kubernetes 1.23 or earlier. This also covers an example scenario for migrating from dockershim to containerd. Alternative container runtimes can be picked from this [page](/docs/setup/production-environment/container-runtimes/).
##
Install containerd. For more information see [containerd's installation documentation](https://containerd.io/docs/getting-started/) and for specific prerequisite follow [the containerd guide](/docs/setup/production-environment/container-runtimes/#containerd).
## Drain the node
```shell kubectl drain <node-to-drain> --ignore-daemonsets ```
Replace `<node-to-drain>` with the name of your node you are draining.
## Stop the Docker daemon
```shell systemctl stop kubelet systemctl disable docker.service --now ```
## Install Containerd
Follow the [guide](/docs/setup/production-environment/container-runtimes/#containerd) for detailed steps to install containerd.
1. Install the `containerd.io` package from the official Docker repositories. Instructions for setting up the Docker repository for your respective Linux distribution and installing the `containerd.io` package can be found at [Getting started with containerd](https://github.com/containerd/containerd/blob/main/docs/getting-started.md).
1. Configure containerd:
```shell sudo mkdir -p /etc/containerd containerd config default | sudo tee /etc/containerd/config.toml ``` 1. Restart containerd:
```shell sudo systemctl restart containerd ```
Start a Powershell session, set `$Version` to the desired version (ex: `$Version="1.4.3"`), and then run the following commands:
1. Download containerd:
```powershell curl.exe -L https://github.com/containerd/containerd/releases/download/v$Version/containerd-$Version-windows-amd64.tar.gz -o containerd-windows-amd64.tar.gz tar.exe xvf .\containerd-windows-amd64.tar.gz ```
2. Extract and configure:
```powershell Copy-Item -Path ".\bin\" -Destination "$Env:ProgramFiles\containerd" -Recurse -Force cd $Env:ProgramFiles\containerd\ .\containerd.exe config default | Out-File config.toml -Encoding ascii
# Review the configuration. Depending on setup you may want to adjust: # - the sandbox_image (Kubernetes pause image) # - cni bin_dir and conf_dir locations Get-Content config.toml
# (Optional - but highly recommended) Exclude containerd from Windows Defender Scans Add-MpPreference -ExclusionProcess "$Env:ProgramFiles\containerd\containerd.exe" ```
3. Start containerd:
```powershell .\containerd.exe --register-service Start-Service containerd ```
## Configure the kubelet to use containerd as its container runtime
Edit the file `/var/lib/kubelet/kubeadm-flags.env` and add the containerd runtime to the flags; `--container-runtime-endpoint=unix:///run/containerd/containerd.sock`.
Users using kubeadm should be aware that the kubeadm tool stores the host's CRI socket in the
`/var/lib/kubelet/instance-config.yaml` file on each node. You can create this `/var/lib/kubelet/instance-config.yaml` file on the node.
The `/var/lib/kubelet/instance-config.yaml` file allows setting the `containerRuntimeEndpoint` parameter.
You can set this parameter's value to the path of your chosen CRI socket (for example `unix:///run/containerd/containerd.sock`).
## Restart the kubelet
```shell systemctl start kubelet ```
## Verify that the node is healthy
Run `kubectl get nodes -o wide` and containerd appears as the runtime for the node we just changed.
## Remove Docker Engine
If the node appears healthy, remove Docker.
```shell sudo yum remove docker-ce docker-ce-cli ```
```shell sudo apt-get purge docker-ce docker-ce-cli ```
```shell sudo dnf remove docker-ce docker-ce-cli ```
```shell sudo apt-get purge docker-ce docker-ce-cli ```
The preceding commands don't re …(trimmed)