mariamgad/kubeadm-ansible

kubeadm-ansible

Overview

Create Kubernetes Cluster with Kubeadm using ansible on CentOS 8
Kubernetes is a container orchestration system that manages containers at scale.
Kubeadm automates the installation and configuration of Kubernetes components such as the API server, Controller Manager, and Kube DNS.

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Prerequisite

• Ansible master node

  • Install python3 sudo yum install python3
  • Install git sudo yum install git
  • Install ansible sudo yum install epel-release , sudo yum install ansible
  • Set Passwordless authentication between master and hosts (kuberenetes nodes) ssh-keygen , ssh-copy-id root@IP_address
  • Add inventory file has all hosts

  [masters]
  master ansible_host=node_IP  ansible_user=root
  
  [workers]
  worker1 ansible_host=node_IP ansible_user=root
  

• Kubernetes master and worker nodes

  • in /etc/hosts add

  master_IP   master    masternode_hostname
  worker_IP   worker    workernode_hostname
  

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Installation Steps

• Allow Firewall ports

  • ports needed to be opened on master node
    
  • ports needed to be opened on worker node
    
    note: you can also disable Firewall service instead

• Configure Kubernetes dependencies

  These configurations are done on both master and worker Kubernetes nodes

  • Disable SELinux service
  • Disable Swapping on
  • Install CRI-O a Container runtime
  • Install Kubeadm a CLI tool that will install and configure the various components of a cluster.
  • Install kubelet a system service that runs on all nodes and handles node-level operations.
  • Install kubectl a CLI tool used for issuing commands to the cluster through its API Server.

• Setting Up the Master Node

  • Initialize the cluster by running kubeadm init
  • Create a .kube directory at /home/cloud. This directory will hold configuration information such as the admin key files, which are required to connect to the cluster, and the cluster’s API address.
    note: cloud is a non-root user should be added before
  • Copy the /etc/kubernetes/admin.conf file that was generated from kubeadm init to your non-root cloud user’s home directory.
  • Run kubectl apply to install Flannel.