5

1. Offical introduction to playbook
   You can get official reference of playbook from below url:
   https://docs.ansible.com/ansible/latest/user_guide/playbooks_intro.html#playbook-syntax
2. Key element of playbook
   

   Task	The management activities we are going to perform for remote servers
   Variables	Variables we can use in the playbook YAML file, including user defined variables, built-in variables, and also variables defined in Inventory file
   Template	Template file with a syntax, like some configuration files etc.
   Handlers	Handlers working with notify, while the activities match a condition, then it's trigger the handler to perform some specific action
   Tags	Mark the task in playbook with a tag, while we execute the playbook, we can specify which task to be executed by specify the tag name, like: ansible-playbook hosts.yml --tags="only"

   
   
   
   
   
   
   
   
   
   
   
3. Ansible playbook syntax
   Below is an example of the playbook should be looks like:
   

   ---
   - hosts: webservers
     remote_user: root
     vars:
       filename: readme.txt
   
     tasks:
       - name: create readme file
         file: name=/tmp/{{filename}} state=touch
       - name: create new user
         user: name=wayne03 state=present shell=/bin/bash

   By execute above playbook, save above content to file named test.yml, you can run below command:

   ansible-playbook test.yml

   

   Then switch to shell-node1, verify if the readme.txt and user wayne03 been created or not: