Installing Kubernetes on RHEL based OS like CentOS 8: Why is it so difficult?

Question

I'm trying to install kubernetes on Oracle Linux 9. I just can't find kubernetes packages.

Executing sudo dnf search kubelet kubectl kubeadm kubernetes-cni cri-tools returns no packages found.

1.Docker is successfuly installed

2.The Kubernetes package manager(/etc/yum.repos.d/kubernetes.repo) configured correctly and contains:

[kubernetes]
baseurl = https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64
enabled = 1
gpgcheck = 1
gpgkey = https://packages.cloud.google.com/yum/doc/yum-key.gpg https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
name = Kubernetes Repository

3.Executing the command "sudo dnf install -y kubelet kubeadm kubectl" eturns the following errors:

Error:
 Problem 1: cannot install the best candidate for the job
  - package kubelet-1.27.3-0.x86_64 does not have a compatible architecture
  - nothing provides libpthread.so.0(GLIBC_2.2.5)(64bit) needed by kubelet-1.27.3-0.x86_64
  - nothing provides libpthread.so.0(GLIBC_2.3.2)(64bit) needed by kubelet-1.27.3-0.x86_64
  - nothing provides libc.so.6(GLIBC_2.2.5)(64bit) needed by kubelet-1.27.3-0.x86_64
  - nothing provides libresolv.so.2(GLIBC_2.2.5)(64bit) needed by kubelet-1.27.3-0.x86_64
  - nothing provides kubernetes-cni >= 1.1.1 needed by kubelet-1.27.3-0.x86_64
 Problem 2: cannot install the best candidate for the job
  - package kubeadm-1.27.3-0.x86_64 does not have a compatible architecture
  - nothing provides kubernetes-cni >= 0.8.6 needed by kubeadm-1.27.3-0.x86_64
  - nothing provides cri-tools >= 1.19.0 needed by kubeadm-1.27.3-0.x86_64
  - nothing provides kubectl >= 1.19.0 needed by kubeadm-1.27.3-0.x86_64
  - nothing provides kubelet >= 1.19.0 needed by kubeadm-1.27.3-0.x86_64
 Problem 3: cannot install the best candidate for the job
  - package kubectl-1.27.3-0.x86_64 does not have a compatible architecture

isn't https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64 the right package repository? Do you see something wrong in my configuration?

Answer 1

There are a few reasons why installing Kubernetes on RHEL-based OSes like CentOS 8 can be difficult.

• RHEL is a commercial OS ( Need to rely on third-party documentation or support).
• RHEL has a number of security features that can conflict with Kubernetes
• K8s installation process on RHEL is more complex than on other operating systems.

Let's start with installation steps for Kubernetes on CentOS 8

1. Update

Update your system. Run the following command to update your system packages:

sudo dnf update

2. Install Docker

Install Docker. Kubernetes requires Docker to run containers, so you will need to install Docker first. Run the following command to install Docker:

sudo dnf install docker

3. Add the Kubernetes repository

Add the Kubernetes repository. Kubernetes does not come pre-installed on CentOS 8, so you will need to add the Kubernetes repository to your system.

sudo dnf config-manager --add-repo https://packages.kubernetes.io/yum/repos/kubernetes-el8-x86_64

4. Install K8s

Now that you have added the Kubernetes repository, you can install Kubernetes. Run the following command to install Kubernetes:

sudo dnf install kubelet kubeadm kubectl

5. Initialise the Kubernetes cluster

Once you have installed Kubernetes, you need to initialize the Kubernetes cluster. Run the following command to initialize the Kubernetes cluster:

 sudo kubeadm init

This command will generate a token that you will need to join the worker nodes to the cluster.

6. Join the worker nodes to the cluster.

Once you have initialized the Kubernetes cluster, you need to join the worker nodes to the cluster. Run the following command on each worker node to join the cluster:

sudo kubeadm join <master_node_ip>:6443 --token <token> --discovery-token-ca-cert-hash sha256:<hash>

Replace <master_node_ip> with the IP address of the master node, and with the token that was generated when you initialized the cluster.

Verify the installation.

Once you have joined the worker nodes to the cluster, you can verify the installation by running the following command:

kubectl get nodes

This command will list all of the nodes in the cluster.

That's it! You have now successfully installed Kubernetes on CentOS 8

For reference, Installation of Kubernetes on Ubuntu [here][1]