DevOps Classroom notes 24/Feb/2024

Ansible contd

using modules

• Ansible has lots of modules Refer Here
• Using Module

<module-name>:
  <parameter-1-name>: <value>
  ...
  <state>: <desired state>

• Refer paramters section in module documentation and fill the values

Activity 1: Install Nginx

• Finding Manual steps: Refer Here

sudo apt update
sudo apt install nginx

• Testing manual steps
• Find module for every manual step
• Create a Playbook
• Refer Here for the changes done
• Lets perform syntax check
  
• Lets execute dry run (doesnot work in all cases)
  
• Now lets execute the playbook
  
• Navigate to public ip
  

Activity 2: Install Apache

• Overview
  
• Manual steps

# ubunu
sudo apt update
sudo apt install apache2 -y
sudo systemctl enable apache2
sudo systemctl start apache2

# redhat steps
sudo dnf install httpd
sudo systemctl enable httpd.service
sudo systemctl start httpd.service

• Daemon: This is an application designed to run in background. To ensure this application starts when your machine is started we have to enable the daemon/service

sudo systemctl => control daemons
sudo service  => control daemons

• Daemon in ubuntu: generally after install softwares the daemon is mostly enabled
• Daemon in Redhat: we have to enable and start the daemon or service
• Execute the ansible playbook
  
• Problems to be addressed:
  • redhat 9 issue
  • why check doesn’t work all the time

adhoc command

• Ansible automation can be executed using two approaches
  • imperative: using ansible commands (adhoc)
  • declrative: writing playbooks
• Adhoc command: Refer Here

ansible -i <inventory> -m "<module name>" -a "parameter1=value1 parameter2=value2"

• Adhoc command for uninstallign ansible

ansible -i hosts -m apt -a "name=nginx purge=true state=absent"