Ansible playbook for kubeadm-based Kubernetes cluster installation on Linux

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This Ansible playbook automates the installation and configuration of a Kubernetes cluster on Linux, with a single control plane node and multiple worker nodes, using the most recent stable Kubernetes release.

Suitable Environment : Development & Testing

System Requirements : Minimum 2 GB RAM & 2 vCPU

Supported Platforms : Baremetal, Virtual Machines, Cloud Instances

Supported Linux distributions :

• RedHat-based ( Fedora, RHEL, Rocky Linux, Almalinux, Oracle Linux )
• Debian-based ( Debian, Ubuntu )
• SUSE-based ( OpenSUSE, SLES )

Also, the latest stable versions of the following components will be installed.

• Container runtime : containerd
• Low-level container runtime : runc ( dependency for containerd )
• CNI plugin used : calico CNI
• Optionally, you can also install
  • CSI drivers for kubernetes :
    • csi-driver-nfs
    • csi-driver-smb
  • MetalLB LoadBalancer for kubernetes.

Please install Ansible if you haven't already.

• Create a common Linux user on all nodes to be used for the cluster.
• Enable passwordless SSH authentication from the Ansible host to all cluster nodes.
• Ensure that the common user has sudo privileges without a password on all cluster nodes.

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Workflow:

1) Download the tarball for the most recent stable release of this Ansible project.

var_latest_version=$(curl -skL https://api.github.com/repos/Muthukumar-Subramaniam/install-k8s-on-linux/releases/latest | jq -r '.tag_name' 2>>/dev/null | tr -d '[:space:]')

wget https://github.com/Muthukumar-Subramaniam/install-k8s-on-linux/releases/download/${var_latest_version}/inst-k8s-ansible.tar.gz

tar -xzvf inst-k8s-ansible.tar.gz

cd inst-k8s-ansible

2) Update the host-control-plane file with the necessary hostname.

3) Update the host-workers file with the necessary hostnames.

4) Update the pod-network-cidr file with the desired pod network CIDR.

• Only private IP addresses, as defined in RFC 1918 are allowed.
• The deployment is configured to accept CIDR prefixes exclusively within the /16 to /28 range.
• Ensure that the selected CIDR prefix does not conflict with any existing networks in your infrastructure.
• Choose a CIDR prefix that provides sufficient address space for your cluster.

5) Run the setup.py script to prepare the environment for the Ansible playbook.

./setup.py

6) Run the playbook if the setup.py script completes successfully.

./inst-k8s-ansible.yaml

Expected Outcome:

7) Once the Kubernetes cluster is successfully installed and ready, you can optionally install the following CSI drivers.

./optional-k8s-csi-nfs-driver.yaml

Expected Outcome:

./optional-k8s-csi-smb-driver.yaml

Expected Outcome:

8) You can also optionally install the MetalLB LoadBalancer if required.

Note: Please make sure to change the address pool range in the playbook as per your environment and requirement.

./optional-install-metallb.yaml

Expected Outcome:

Kindly note:

• This playbook is a useful resource for experimenting with Kubernetes and can be customized to meet your specific requirements.
• The playbook utilizes the GitHub API to fetch the current stable versions of all required software components.
• Compatible with a wide range of Linux distributions.
• Your feedback and contributions are invaluable to the success of this project.
• Please report any bugs, suggest new features, or contribute directly to the codebase.

Have lots of fun!