Automating Kubernetes Cluster Setup using Ansible

Task Overview

This Task aims to automate the setup of a production-ready Kubernetes cluster using Ansible. The automation will handle installing essential Kubernetes components (kubeadm, kubelet, kubectl), configuring networking (Calico or Flannel), and ensuring seamless cluster operations.

Task Scope

• Provision Virtual Machines
  • Use AWS EC2 instances or bare-metal VMs (Ubuntu 22.04 or CentOS 8).
  • Setup a master node and multiple worker nodes.
• Install and Configure Kubernetes Components
  • Install Docker as a container runtime.
  • Install kubeadm, kubelet, and kubectl using Ansible.
  • Initialize the Kubernetes cluster on the master node using kubeadm.
  • Join worker nodes to the cluster automatically.
• Networking Setup
  • Deploy a networking plugin:
  • Calico for network policies & scalability.
  • Flannel for simple overlay networking.
  • Configure necessary firewall rules (ports, IP forwarding).
• Cluster Configuration and Testing
  • Verify cluster health (kubectl get nodes).
  • Deploy a sample Nginx application for testing.

Technologies Used

• Ansible – Automates Kubernetes installation.
• Kubernetes – Container orchestration system.
• Kubeadm – Bootstraps Kubernetes clusters.
• Calico / Flannel – Network plugins.
• Docker / containerd – Container runtime.
• AWS / VMs – Infrastructure for deployment.

Implementation Steps

1. Infrastructure Provisioning

• Using AWS: Provision EC2 instances using Terraform or manual setup.
• On-premises: Use VirtualBox or cloud VMs.
• Allocate at least:
• 1 Master Node: 2 vCPU, 4GB RAM
• 2 Worker Nodes: 2 vCPU, 4GB RAM each

2. Install Ansible on the Control Machine

sudo apt update && sudo apt install -y ansible

3. Create an Ansible Inventory File

Define the Kubernetes master and worker nodes in inventory.ini:

[master]
master-node ansible_host=192.168.1.100

[workers]
worker-node-1 ansible_host=192.168.1.101
worker-node-2 ansible_host=192.168.1.102

[k8s_cluster:children]
master
workers

4. Write Ansible Playbooks

Playbook 1: Install Dependencies (Docker, kubeadm, kubelet, kubectl)

- name: Install Kubernetes Dependencies
  hosts: k8s_cluster
  become: yes
  tasks:
    - name: Install required packages
      apt:
        name: ['curl', 'apt-transport-https', 'ca-certificates']
        state: present
        update_cache: yes

    - name: Install Docker
      apt:
        name: docker.io
        state: present

    - name: Add Kubernetes GPG key
      shell: curl -fsSL https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -

    - name: Add Kubernetes Repository
      shell: echo "deb https://apt.kubernetes.io/ kubernetes-xenial main" | tee -a /etc/apt/sources.list.d/kubernetes.list

    - name: Install kubeadm, kubelet, and kubectl
      apt:
        name: ['kubelet', 'kubeadm', 'kubectl']
        state: present
        update_cache: yes

    - name: Enable kubelet service
      systemd:
        name: kubelet
        enabled: yes

Playbook 2: Initialize Kubernetes Master

- name: Initialize Kubernetes Master
  hosts: master
  become: yes
  tasks:
    - name: Initialize the cluster
      shell: kubeadm init --pod-network-cidr=192.168.0.0/16
      register: kubeadm_output
      changed_when: true

    - name: Copy kubeconfig to user directory
      shell: |
        mkdir -p $HOME/.kube
        cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
        chown $(id -u):$(id -g) $HOME/.kube/config

Playbook 3: Configure Networking (Calico or Flannel)

For Calico:

- name: Deploy Calico Network Plugin
  hosts: master
  become: yes
  tasks:
    - name: Apply Calico YAML
      shell: kubectl apply -f https://docs.projectcalico.org/manifests/calico.yaml

For Flannel:

- name: Deploy Flannel Network Plugin
  hosts: master
  become: yes
  tasks:
    - name: Apply Flannel YAML
      shell: kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

Playbook 4: Join Worker Nodes

- name: Join Worker Nodes to the Cluster
  hosts: workers
  become: yes
  tasks:
    - name: Join the cluster
      shell: "{{ hostvars['master-node']['kubeadm_output'].stdout_lines | select('match', '^kubeadm join') | list | first }}"
      args:
        chdir: $HOME

Validation Steps

1. Check cluster status:

kubectl get nodes

2. Verify pod networking

kubectl get pods -n kube-system

3. Deploy a test application:

kubectl create deployment nginx --image=nginx
kubectl expose deployment nginx --port=80 --type=NodePort

4. Test application

kubectl get svc nginx
curl http://:

Project Benefits

• ✅ Automated Setup: Reduces manual errors and ensures consistency.
• ✅ Scalability: Easily add more nodes using Ansible.
• ✅ Modular Deployment: Can switch between Calico and Flannel.
• ✅ Production-Ready: Secure and reliable Kubernetes cluster.

Next Steps

• 🔹 Implement HA (High Availability) Kubernetes
• 🔹 Integrate Helm for package management
• 🔹 Add Monitoring with Prometheus & Grafana
• 🔹 Deploy Ingress Controllers for better traffic management

This project provides a fully automated Kubernetes setup with Ansible and networking configuration, ready for real-world implementation.