Building a Kubernetes Cluster from Scratch: Part 2 - Installing Container Runtime and Kubernetes Components

This is the second part of my Kubernetes installation series using kubeadm. In Part 1, I covered the environment preparation, including hardware requirements and network configuration, as well as required Linux kernel modules.

In this Part 2, I'll continue by installing and configuring containerd as my container runtime and the installation of the essential Kubernetes componets like kubeadm, kubelet, and kubectl.

Installing the container runtime

Kubernetes is a container orchestration system, and as such it needs a container runtime responsible for running the containers in the cluster. The container runtime pulls the images, starts/stops the containers and report container status back to Kubernetes.

Before installing the container runtime, we need to download the GPG keys to ensure the packages haven't been tampered with, and apt will need this information later as well.

root@cp:~# curl -fsSL https://download.docker.com/linux/ubuntu/gpg \
| gpg --dearmor -o /etc/apt/keyrings/docker.gpg
root@cp:~#
root@cp:~# echo \
"deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] \
https://download.docker.com/linux/ubuntu \
$(lsb_release -cs) stable" | tee /etc/apt/sources.list.d/docker.list > /dev/null

Now we install containerd

root@cp:~# apt-get update && apt-get install containerd.io -y
root@cp:~# containerd config default | tee /etc/containerd/config.toml
root@cp:~# systemctl restart containerd

Installing the Kubernetes software

First, like with containerd, we need to download the public key for the package repositories.

root@cp:~# curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.31/deb/Release.key \
| sudo gpg --dearmor -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg

# Add the appropriate k8s repository
root@cp:~# echo "deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] \
https://pkgs.k8s.io/core:/stable:/v1.31/deb/ /" \
| tee /etc/apt/sources.list.d/kubernetes.list

Finally, update the repo and install the Kubernetes software

root@cp:~# apt-get update
root@cp:~# apt-get install -y kubeadm=1.31.1-1.1 kubelet=1.31.1-1.1 kubectl=1.31.1-1.1

In the next part of this series, I will set the local DNS alias for my cp Kubernetes server and assign it with the name k8scp. Then I will create a configuration file for the cluster.