DevOps Classroom Series – 07/Mar/2020

How Ansible Works

• User writes declarative stuff in playbooks
• User creates inventory (list of nodes)
• User executes playbook with the inventory
• Now ansible converts the playbook into python objects
• With the user credentials configured ansible log’s using (ssh/any other communication protocol) and executes the converted python code and displays the result to the user.

Ansible Terms

• Playbook: Declarative specification for your application deployment using YAML.
• Inventory: Node information.(List of nodes)
• Ansible Control Server: The machine/system on which ansible is installed
• Managed Node or Node: The machine/system which has python installed and which we want to control from Ansible.

Install Ansible

• Refer Video Content

Installation

• Create 2 t2.micro with ubuntu 18 image
• Login into ansible control server
  • Windows 10 (with no updates) or Windows 7 : Install Git for windows from here
• Install ansible from here

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

• Login into node

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

• We need to configure an admin user on the ansible control server and also nodes
• Login into ansible control server and
  • Ensure password based authentication is enabled
  • Create a user called as admin
  • Give admin user sudo privileges
  • Now create a key for the user admin
• Login into node
  • Ensure password based authentication is enabled
  • Create a user called as admin
  • Give admin user sudo privileges
  • Now create a key for the user admin
• Login into ansible control server
  • Copy the public key to ansible node for seamless authentication