Ansible Contd

YAML

• It is a Data Description Format.
• It is widely used to store
  • Data
  • Configurations
• Data can be categorized into 2 types
  • Simple/Scalar:
    • Text name: Ansible
    • Number version: 2.13
    • Boolean opensource: yes
  • Complex
    • list/array (plural)
      “`yaml
      colors:</li>
      <li>red</li>
      <li>blue</li>
      <li>green
      “`
    • object/map/dictionary
      yaml
address:
flatno: 407
building: mythrivanam
city: Hyderabad
• JSON/YAML use Key-Value (Name Value) pairs.
• YAML Basic key value syntax is key: value
• Sample YAML (Quality Thought)

---
name: QualityThought
contact:
  email: 
    - support@qualitythought.in
    - qualitythought.in@gmail.com
  phone:
    - 999999999
    - 888888888
address:
  - flat: 407
    building: mythrivanam
    city: Hyderabad
  - flat: 302
    building: Nilgiri
    city: Hyderabad

• Good books to read

---
Purpose: Good Books to Read
Books:
  - Title: Your Brain at Work
    Author: David Rock
    ISBN: 978-0062312822
    Language: English
  - Title: Rich Dad Poor Dad
    Author: Robert Kiyosaki
    ISBN: 978-1612680194
    Language: English
  - Title: Who moved my cheese
    Author: Spencer Johnson
    ISBN: 978-0091883768
    Language: English

• Write a yaml describing your favorite movies/holiday destinations

---
movies:
  - name:
    starcast:
      - 
      -
    technical:
      director:
      producer:
    release: 
  - 
  -

destinations:
  - name:
    modeoftransport: 
    spots:
      -
      -
      -

• YAML files are generally stored with extensions .yaml or .yml

Ansible Playbook

• Refer Here for official docs
• The structure of the YAML is defined by Ansible

---
- name: <purpose>
  hosts: <where to execute>
  become: yes # whether to run the tasks with sudo
  tasks:
    - name: <task description> # individual step
      <module-name>:
         <param-1>: <value-1>
         ..
         <param-n>: <value-n>
    - name: <task description>
      <module-name>:
         <param-1>: <value-1>
         ..
         <param-n>: <value-n>
         state: <desired-state>

Lets write a playbook for Apache installation

• Manual steps

sudo apt update
sudo apt install apache2 -y

• Google apt in ansible Refer Here for the module page
• Go through parameters and fill in the necessary parameters
• Playbook: Refer Here for the changes done
• Executing ansible playbook: Refer Here
  
  
• Now re-execute the same command and ansible will not install apache2 but since apache2 exists it doesn’t change any thing