DevOps Classroom Series – 12/Apr/2020

How to use custom roles

  • Now Create a playbook to execute the roles
  • Roles are generally referred from playbooks
    • Roles will be checked in
      1. relative to playbook filepath (./roles/<role-name>)
      2. in the home directory (~/.ansible/roles/<role-name>)
      3. in the ansible cfg directory (/etc/ansible/roles/<role-name>)
  • Refer here for the playbook scripts

Dynamic Inventory

  • Refer here for official docs
  • Dynamic inventory is a script written in any language which returs a json file in a particular structure when –hosts is called or when –list
  • Sample Structure of json
    'web': {
        'hosts': ['', ''],
        'vars': {
            'package_name': 'httpd',
            'ansible_ssh_user': 'ubuntu' 
    'db': {
        'hosts': ['', ''],
        'vars': {
            'username': 'admin',
            'password': 'admin@123'

Ansible Tower

  • Is an orchestration tool around ansible which can be used using

    • Web Pages
    • REST API
  • Ansible Tower is a paid tool

  • For the labsetup, we would use a Ansible Tower trail version

  • Ansible Tower Quick Start Guide Refer Here

  • Using Ansible Tower is all about configuring ansible-playbook executions from ui/periodic scheduled jobs and from rest api .

  • For Rest API refer here

  • Ansible Tower will maintain logs of every run done by ansible.

Enterprise Scenario

  • After writing Ansible Playbooks/Roles etc you need to run them from CI/CD Tools (like Jenkins/Azure DevOps) or from InfraProvisioning tools like Terraform/CloudFormation/ARM Templates


  1. Refer Here

  2. Write an Ansible Role to configure Tomcat 8 and then add playbooks to deploy gameoflife and openmrs into the Tomcat 8 Download Here

How to run the same ansible playbook for multiple environments

  • Lets assume you have role called as tomcat8
  • Lets assume you have a playbook called as useroledemo.yml
  • Now lets assume we have 4 environments
    • dev
    • QA
    • Automated-QA
    • UAT
  • Solution: For every environment create a separate inventory file
    • dev_hosts => ansible-playbook -i env\dev_hosts useroledemo.yaml
    • QA_hosts => ansible-playbook -i env\QA_hosts useroledemo.yaml
    • Automated-QA_hosts => ansible-playbook -i env\Automated-QA_hosts useroledemo.yaml
    • UAT_hosts=> ansible-playbook -i env\UAT_hosts useroledemo.yaml

Can i run Ansible Playbook on 100 nodes at same time

  • Ansible-PLaybook has option called as forking (-f), if you want to run ansible on 100 servers at same time use “`ansible-playbook -f 100 useroledemo.yml’
  • To run ansible-playbook on one server at a time
ansible-playbook -f 1 useroledemo.yml

What is synchronize module

  • To recursively copy file then use synchronize module Refer Here

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