DevOps Classroom Series – 23/Dec/2020

Inventories

• In Ansible inventories are list of nodes
• Inventories can be static or dynamic
• Inventories can be written in two formats in static
  • INI
  • YAML
• Inventory orderding: A new play level keyword called as order is added which supports the following values
  • inventory: This is default. It simply means Ansible will execute the order in the way they are written in inventory
  • reverse_inventory
  • sorted: hosts are alphabetically sorted
  • reverse_sorted: hosts are reverse alphabetically sorted
  • shuffle

INI

• In Inventories entries can be grouped together

[group1]
10.100.100.101
10.200.10.101

[group2]
192.168.10.11
192.168.11.11

[group3]
10.200.10.101
192.168.11.11

[group4:children]
group1
group2

• In any inventory ansible will have two default groups
  • all: This is list of the nodes (unique)
  • ungrouped: This is list of the nodes which donot belong to any group.

Ansible Inventory Scenarios

• Scenario-1:

  • Install utility Softwares like git, tree and nano on all machines
    • manual steps:
      • ubuntu sudo apt install git tree nano -y
      • rhel sudo yum install git tree nano -y
    • In ansible we have a generic package module Refer Here.
    • Refer Here for the changes
  • Install apache on centos
    • manual steps:

    sudo yum install httpd
    sudo systemctl enable httpd
    sudo systemctl start httpd
    

    • Refer Here for the changeset
  • Install java on ubuntu
    • Refer Here for the changeset

• As of now we have two nodes

  • node-1: ubuntu
  • node-2: centos

• Scenario 2: Install Lamp stack on webservers. In web servers we have ubuntu and centos nodes. Try Creating one playbook for this.

  • ubuntu: manual steps
    • sudo apt update
    • sudo apt install apache2 -y
    • sudo apt install php libapache2-mod-php php-mysql php-cli -y
    • echo "<?php phpinfo(); ?>" > /var/www/html/info.php
  • centos: manual steps
    • sudo yum install httpd -y
    • sudo systemctl enable httpd.service
    • sudo systemctl start httpd.service
    • sudo yum install php php-mysql php-fpm -y
    • echo "<?php phpinfo(); ?>" > /var/www/html/info.php