DevOps Classroom notes 07/Oct/2023

Ways of Working in Ansible

• Figure out the manual steps
• Execute and verify if they are working
• for each manual step findout an ansible module which can help

Ansible Module

• this is the smallest unit of work in Ansible
• Module takes some inputs which are generally referred as parameters and it has state
• Ansible modules Refer Here

Ansible Execution Approaches

• Adhoc command: This uses the following structure and it is used for non repetitive tasks

ansible -m "<module-name>" -a "<arguments>" <where>

• Playbook: This is yaml representation of sequence of commands and it is designed to be reptitive.

Activity: install apache server on node 1

• manual steps: Refer Here

sudo apt update
sudo apt install apache2 -y

• Finding modules
  
• Dev Env: Use Visual studio code and install ansible extension from Redhat
  
• Refer Here for the changes
• Syntax check

ansible-playbook --syntax-check -i <path to inventory> <path to playbook.yaml>
ansible-playbook --syntax-check -i hosts activity1.yaml

* Check the execution (dry run). Note this is not always correct

ansible-playbook --check -i <path to inventory> <path to playbook.yaml>
ansible-playbook --check -i hosts activity1.yaml

* Now lets execute the playbook

ansible-playbook -i <path to inventory> <path to playbook.yaml>
ansible-playbook -i hosts activity1.yaml

* Now lets rerun

Activity 2: Install php on apache server

• Manual steps: Refer Here for getting the steps

sudo apt udpate 
sudo apt install apache2 -y
sudo apt install php libapache2-mod-php php-mysql -y

• Lets create a file /var/www/html/info.php with the following content

<?php phpinfo(); ?>

• Now access http://publicip/info.php
  
• Refer Here for the changes done
• Execute ansible playbook after syntax check and check

ansible-playbook -i hosts php.yaml

Activity 3: Perform the activity2 on redhat

• I need to setup a redhat vm with devops user
• manual steps:

sudo dnf install httpd -y
sudo dnf install php php-cli php-common php-gd php-mysqlnd php-pdo -y

• Lets create a file /var/www/html/info.php with the following content

<?php phpinfo(); ?>

• Refer Here for the playbook
• Execute ansible playbook after syntax check and check

ansible-playbook -i hosts php.yaml

• We need to start the service Refer Here for the changes done to start and enable the service
  

Activity 4: Use the same playbook for ubuntu and redhat machines

• To do this activity, the two topics which we need to understand are
  • inventory groups
  • facts