This presentation covers the fundamentals of Ansible and it is useful for the people who are seeking information to start using Ansible, what it is capable of and how to use it right. I purposely made syntax errors in certain slides to demonstrate how to fix such errors and giving the idea of the importance to write syntax right. If you have any questions please don't hesitate to contact me over my mail address judeashan@gmail.com. All the best!!

1. Ansible
DevOps for people who hate DevOps
Jude Ashan | Senior System Engineer | Tiqri Corporation (Pvt) Ltd.

2. State of Ops

3. I know, I’ll write code
to tell the computer
how to set up itself!

4. What is Ansible
● A configuration management tool.
● Deployment tool.
● Ad-hoc task execution tool.
● Developed by Michael DeHaan.
● Userbase includes NASA, Apple, Juniper
All-in-one tool

5. Why Ansible over other competitive tools
● Easy
○ Uses SSH (with one python requirement).
○ Agent-less.
○ Can install Ansible with one command.
○ Syntax do not need to be memorized.
○ Push-Based.
● Simple
○ No development knowledge required.
○ Human readable.
○ Built-in Modules.

6. Ansible consists with
● Inventory
● Ad Hoc Commands
● Playbooks
○ Tasks
○ Variables
○ Templates
○ Handlers
○ Roles
● Modules (inbuilt & custom)
● Plugins (emails, logging, etc.)

7. Ansible Architecture

8. ● Inventory - /etc/ansible/hosts file (for static inventory).
● Sample -
[col_dev_db_master]
192.168.133.53
[col_dev_micro_bo]
192.168.133.42
192.168.132.189
192.168.133.52
* Dynamic inventory is managed using tags provided by server farm vendor.
Ansible Inventory (hosts file)

9. Ad Hoc Commands - Why?
● To make sys admin’s life easy to manage high no. of servers.
● Will be used to check
○ Check log files
○ Check resource usage
○ Manage system users and groups
○ Check for patches and apply updates using package managers
○ Deploy applications
○ Manage cron jobs
○ Reboot servers.

10. $ ansible all -m ping
$ ansible all -a "hostname"
$ ansible all -a 'df -h'
$ ansible all -b -m yum -a 'name=ntp state=present'
$ ansible col_dev_db_master -b -m yum -a "name=mariadb-server state=present"
$ ansible all -b -m user -a "name=devopsadmin group=admin createhome=yes"
$ ansible col_dev_micro_bo -m copy -a "src=test.txt dest=/tmp/"
$ ansible col_dev_micro_bo -m file -a "dest=/tmp/test.txt state=absent"
Ad Hoc Commands - How?

11. About Playbooks
● Powerful configuration management tool.
● Playbook is a file written in YAML syntax.
● Any number of plays can be run in a playbook. Each play has a task.

12. Let’s get our hands dirty with
Ansible Playbooks

13. - hosts: col_dev_micro_bo
become: yes
become_method: sudo
remote_user: root
tasks:
- name: Install Apache Web Server
yum:
name: httpd
state: present
- name: Enable and start Apache Web Server
service:
name: httpd
state: started
enabled: yes
Lab1 - Install Apache and Enable it on server startup
File name -
/etc/ansible/apache.yml
Command to run playbook -
$ ansible-playbook apache.yml
An example to learn tasks usage.

14. - hosts: col_dev_micro_bo
become: yes
become_method: sudo
remote_user: root
vars:
var_name1: abc
var_name2: xyz
tasks:
- name: Create Directory Structure
file:
path: “{{ item }}”
state: directory
owner: testuser
group: testuser
mode: "0775"
with_items:
- /colombo/red
- /colombo/blue
- /colombo/red/circle
- /colombo/red/square
- "/sydney/opera/{{ var_name1 }}"
- "/sydney/opera/{{ var_name1
}}/triangle"
- "/sydney/opera/{{ var_name2 }}"
- "/sydney/opera/{{ var_name2
}}/triangle"
Lab2 - Create
Directories
File name -
/etc/ansible/directory.yml
Command to run playbook -
$ ansible-playbook directory.yml
An example to learn variables and
loops usage.

15. - hosts: col_dev_micro_bo
vars:
listen_port: 82
serveradmin: its@tiqri.com
remote_user: root
tasks:
- name: ensure apache is at the latest version
yum:
name: httpd
state: latest
- name: write the apache config file
template:
src: /srv/httpd.j2
dest: /etc/httpd.conf
notify:
- restart apache
- name: ensure apache is running
service:
name: httpd
state: started
handlers:
- name: restart apache
service:
name: httpd
state: restarted
Lab3 - Configure Apache
virtual host
File name -
/etc/ansible/apache.yml
Command to run playbook -
$ ansible-playbook apache.yml
An example to learn templates and
handlers usages.

16. Ansible Roles
● What it does?
○ Provides a framework for fully independent, or interdependent collections of variables, tasks,
files, templates, and modules.
○ Breaks “Playbooks” into multiple files.
● Why we need roles?
○ It simplifies writing complex playbooks.
○ It makes them easier to reuse.

17. Ansible Roles
Folder structure as below
/etc/ansibles/hosts
/etc/ansibles/app_servers.yml
/etc/ansibles/db_servers.yml
/etc/ansibles/roles/apache/
|_ /files/mod_jk.so
|_ /handlers/main.yml
|_ /tasks/main.yml
|_ /templates/default_vhost.j2
|_ /vars/main.yml
/etc/ansibles/roles/postgres/
|_ /files/table_reindex.sql
|_ /handlers/main.yml
|_ /tasks/main.yml
|_ /templates/pg_hba.conf
|_ /vars/main.yml

18. Ansible Roles
How Ansible Roles call by a Playbook?

19. - hosts: col_dev_db_master
become: yes
become_method: sudo
remote_user: root
roles:
- role: init
- role: postgres
Lab4 - How Ansible Roles call by a Playbook?
File name -
/etc/ansible/app_servers.yml
Command to run playbook -
$ ansible-playbook testplaybook.yml
An example to learn roles usage in a
playbook.

20. Session
Highlights

21. ● Playbook - to run tasks and roles.
● Roles - to run tasks in more organized and simplest way.
● Handlers - restart to restart services.
● Templates - to push configuration files with respective variables.
● Vars - to define variables.
● Must follow YAML syntax.
● Key authentication should be issued for Ansible master-client communication.
● Complete documentation - https://docs.ansible.com/

22. We are done
THANK YOU
Any Questions?