DevOps Classroomnotes 05/Oct/2023

Ansible contd

Setting up password less authentication between linux machines

• We have two servers with user devops
• From server1 create a key pair

ssh-keygen

* Now copy the public key into server 2 ssh-copy-id <username>@<server-2-ip>
* After the ssh-copy-id is success, then we can login directly by using ip address as both machines have same username and password less authentication is setup

ssh <server-2-ip>

Ansible setup

• we have two machines with common user devops with sudo permissions and password less authentication setup between server 1 and server 2
• From now server 1 will be called as Ansible Control node
  and server 2 as node 1
• Ensure python 3 is installed
• Refer Here for installation guide
• We have two approaches to install ansible
  • using python
  • using package managers like apt or yum (dnf)
• Refer Here for ubuntu specific installation.

sudo apt update
sudo apt install software-properties-common
sudo add-apt-repository --yes --update ppa:ansible/ansible
sudo apt install ansible -y
ansible --version

* Overview

Test ansible connectivity from ansible control node to node 1

• Create a file with node 1 ip address in it
  
• execute the following command ansible -m ping -i hosts all

Adding users to sudo

• Refer Here for debian based systems
• Refer Here for redhat based systems
• In this case we will be editing sudoers file directly

sudo visudo

Exercises

• YAML Refer Here for yaml tutorial
• install the following on ubuntu vm
  • openjdk 17
  • nginx
  • mysql
• openjdk 17

sudo apt update
sudo apt install openjdk-17-jdk -y
java -version

• Install ansible and test connnectiviy between two nodes