🚀 Kubernetes Cluster Setup with Ansible

📌 Overview

Install a Baremetal High-Availability Kubernetes Cluster using Ansible and kubeadm. This playbook automates the setup process and ensures a robust, production-ready environment with:

• Containerd as the container runtime.
• Cilium as the CNI (Container Network Interface).
• HAProxy & Keepalived for control plane load balancing and failover.

📌 Note: A Jumphost is used in the playbook to connect to all nodes.

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🏗 Architecture

The cluster consists of the following components:

🔹 HAProxy Nodes (haproxy group)

• Load balancers using HAProxy for API server traffic.
• Keepalived ensures high availability via a virtual IP (VIP).

🔹 Kubernetes Master Nodes (masters group)

• Control plane nodes running kube-apiserver, kube-controller-manager, kube-scheduler, and etcd.

🔹 Kubernetes Worker Nodes (workers group)

• Nodes responsible for running application workloads.

🔹 Group Relationships

[k8s:children]
masters
workers

[nodes:children]
k8s
haproxy

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📋 Inventory File Format

[haproxy]
web01 ansible_host=<ip> ansible_port=22 ansible_user=ubuntu ansible_ssh_private_key_file=<path_to_private_key>
web02 ansible_host=<ip> ansible_port=22 ansible_user=ubuntu ansible_ssh_private_key_file=<path_to_private_key>

[masters]
master1 ansible_host=<ip> ansible_port=22 ansible_user=ubuntu ansible_ssh_private_key_file=<path_to_private_key>
master2 ansible_host=<ip> ansible_port=22 ansible_user=ubuntu ansible_ssh_private_key_file=<path_to_private_key>
master3 ansible_host=<ip> ansible_port=22 ansible_user=ubuntu ansible_ssh_private_key_file=<path_to_private_key>

[workers]
worker1 ansible_host=<ip> ansible_port=22 ansible_user=ubuntu ansible_ssh_private_key_file=<path_to_private_key>
worker2 ansible_host=<ip> ansible_port=22 ansible_user=ubuntu ansible_ssh_private_key_file=<path_to_private_key>

[kvip]
web01

[all:vars]
ansible_ssh_common_args='-o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -o ProxyCommand="ssh -i <path_to_jumphost_key> -q -W %h:%p ubuntu@<jumphost_floating_ip>"'

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🔧 Playbook Execution Flow

🔘 General Setup:

• Applies basic system configurations to all nodes.

🔘 Kubernetes Prerequisites

• Installs dependencies required for Kubernetes components.

🔘 Containerd Installation

• Installs and configures containerd as the container runtime.

🔘 Kubernetes Installation

• Installs kubeadm, kubelet, and kubectl.

🔘 HAProxy & Keepalived Setup

• HAProxy for API server load balancing.
• Keepalived for a virtual IP, ensuring control plane high availability.

🔘 Master Node Initialization

• The first master node initializes the cluster.

🔘 Worker Nodes Join

• Worker nodes join the cluster using kubeadm.

🔘 Additional Master Nodes Join

• The remaining master nodes join to create a HA control plane.

🔘 Final Configuration

• Configures terminal access and other essential settings.

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⚠️ Missing Elements & Improvements

🔸 Templating for HAProxy & Keepalived 🔸

• HAProxy and Keepalived configuration files should be dynamically generated using Jinja templates.

🔸 Reorganization of the Playbook 🔸

• The playbook structure should be improved for better readability and maintainability.

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🚀 Usage Instructions

1️⃣ Clone the Repository

git clone <repo_url>
cd <repo_directory>

2️⃣ Update the Inventory File

Modify inventory.ini to reflect your infrastructure details.

3️⃣ Run the Playbook

ansible-playbook -i inventory.ini site.yaml

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🔮 Future Enhancements

✅ Implement HAProxy & Keepalived Jinja templates.

💬 Contributions & Feedback

Suggestions are wellcomed! Feel free to open issues or submit pull requests to improve this playbook. 🚀