DevOps Classroomnotes 27/May/2023

Ansible

• Ansible can communicate with nodes by using two approaches
  • adhoc commands:
    • We build a command for desired state
  • playbook:
    • We create a file where we express desired state
    • This is recommended approach for repetitive activites

Playbook

• We have taken a sample playbook

---
- name: hello ansible
  hosts: all
  become: yes
  tasks:
    - name: update packages and install tree
      apt:
        name: tree
        state: present
        update_cache: yes

• We executed playbook
  
• Basic Playbook semantics
  
• In ansible the smallest unit of work is perfomed by module

YAML

• YAML vs JSON
  
• Refer Here for yaml syntax from ansible

Ways of Working (WoW):

• list down all the manual steps
• Ensure all the steps are working
• For each step find a module and express the desired state

Activity 1: Install apache server

• Manual steps

sudo apt update
sudo apt install apache2 -y

• Verify the installation http://<public-ip>
  
• Refer Here for ansible yaml syntax for playbook
• Finding the module:
  • search google with <command> in ansible
    
  • search from ansible docs Refer Here
    
• all the commands for installation are executed with sudo

---
- name: install apache server
  hosts: all
  become: yes
  tasks:
    - name: install apache
      ansible.builtin.apt:
        name: apache2
        update_cache: yes
        state: present

• create inventory

172.31.27.136

• Run the command ansible-playbook -i <inventory-path> <playbook-path>
  
• Execute the playbook
  
• verify the apache