DevOps Classroom Series – Ansible – 11/Nov/2019

Widely Used Modules

• Installations:
  • apt
  • yum
  • package
• Services:
  • service
  • systemd
• Files:
  • file
  • get_url
• Templating
  • template

Sample Deployment in Ansible

• We will try to deploy Apache with PHP modules
• Ubuntu Steps

sudo apt-get update
sudo apt-get install apache2 -y
sudo systemctl enable apache2
sudo apt-get install php libapache2-mod-php php-mysql php-cli -y
sudo vi /var/www/html/info.php
<?php
phpinfo();
?>
sudo systemctl restart apache2

• Centos Steps:

sudo yum install httpd -y
sudo systemctl enable httpd
sudo yum install php php-mysql
sudo vi /var/www/html/info.php
<?php
phpinfo();
?>
sudo systemctl restart httpd

• Initial Playbook for Ubuntu looks as shown below

---
- hosts: all
  become: yes
  tasks:
    - name: install apache2 and update packages
      apt:
        name: apache2
        update_cache: yes
        state: present
    - name: enable and restart apache2 service
      service:
        name: apache2
        enabled: yes
        state: restarted
    - name: install php
      apt:
        name: php
        state: present
    - name: install libapache2-mod-php
      apt:
        name: libapache2-mod-php
        state: present
    - name: install php-mysql
      apt:
        name: php-mysql
        state: present
    - name: php-cli
      apt:
        name: php-cli
        state: present
    - name: restart apache2
      service:
        name: apache2
        state: restarted

• Playbook for Redhat/Centos looks as shown below

---
- hosts: all
  become: yes
  tasks:
    - name: install httpd
      yum: 
        name: httpd
        state: present
    - name: enable and restart httpd
      service:
        name: httpd
        enabled: yes
        state: restarted
    - name: install php
      yum:
        name: php
        state: present
    - name: install php-mysql
      yum:
        name: php-mysql
        state: present
    - name: restart httpd
      service:
        name: httpd
        state: restarted

• Ansible Handlers: Refer Here
• Lets change our playbooks by adding handlers.
• Ubuntu Playbook looks as shown below

---
- hosts: all
  become: yes
  tasks:
    - name: install apache2 and update packages
      apt:
        name: apache2
        update_cache: yes
        state: present
      notify:
        - restart and enable apache2
    - name: install php
      apt:
        name: php
        state: present
    - name: install libapache2-mod-php
      apt:
        name: libapache2-mod-php
        state: present
    - name: install php-mysql
      apt:
        name: php-mysql
        state: present
    - name: php-cli
      apt:
        name: php-cli
        state: present
      notify:
        - restart and enable apache2
  handlers:
    - name: restart and enable apache2
      service:
        name: apache2
        enabled: yes
        state: restarted
    

• RedHat Playbook looks as shown below

---
- hosts: all
  become: yes
  tasks:
    - name: install httpd
      yum: 
        name: httpd
        state: present
      notify:
        - restart and enable httpd
    - name: install php
      yum:
        name: php
        state: present
    - name: install php-mysql
      yum:
        name: php-mysql
        state: present
      notify:
        - restart and enable httpd
  handlers:
    - name: restart and enable httpd
      service:
        name: httpd
        enabled: yes
        state: restarted

• Now in the playbooks we can write it in a simplified way using looping constructs Refer Here

• After applying loops ubuntu playbook looks as shown below

---
- hosts: all
  become: yes
  tasks:
    - name: install apache2 and update packages
      apt:
        name: apache2
        update_cache: yes
        state: present
      notify:
        - restart and enable apache2
    - name: install php modules
      apt:
        name: "{{ item }}"
        state: present
      loop:
        - php
        - libapache2-mod-php
        - php-mysql
        - php-cli
      notify:
        - restart and enable apache2
  handlers:
    - name: restart and enable apache2
      service:
        name: apache2
        enabled: yes
        state: restarted
    

• After applying loops redhat/centos playbook looks as shown below

---
- hosts: all
  become: yes
  tasks:
    - name: install httpd
      yum: 
        name: httpd
        state: present
      notify:
        - restart and enable httpd
    - name: install php modules
      yum:
        name: "{{ item }}"
        state: present
      loop:
        - php
        - php-mysql
      notify:
        - restart and enable httpd
  handlers:
    - name: restart and enable httpd
      service:
        name: httpd
        enabled: yes
        state: restarted