Ansible is an incredible configuration management and provisioning utility that enables you to automate all the things. In this series, you’ll learn everything you need to know in order to use Ansible for your day-to-day administration duties.

site.yml (text in bold has been added since the previous version)

 ---
 
 - hosts: all
   become: true
   pre_tasks:
 
   - name: install updates (CentOS)
     tags: always
     dnf:
       update_only: yes
       update_cache: yes
     when: ansible_distribution == "CentOS"
 
   - name: install updates (Ubuntu)
     tags: always
     apt:
       upgrade: dist
       update_cache: yes
     when: ansible_distribution == "Ubuntu"
 
 - hosts: workstations
   become: true
   tasks:
 
   - name: install unzip
     package:
       name: unzip
 
   - name: install terraform
     unarchive:
       src: https://releases.hashicorp.com/terraform/0.12.28/terraform_0.12.28_linux_amd64.zip
       dest: /usr/local/bin
       remote_src: yes
       mode: 0755
       owner: root
       group: root
 
 - hosts: web_servers
   become: true
   tasks:
 
   - name: install httpd package (CentOS)
     tags: apache,centos,httpd
     dnf:
       name:
         - httpd
         - php
       state: latest
     when: ansible_distribution == "CentOS"
 
   - name: start and enable httpd (CentOS)
     tags: apache,centos,httpd
     service:
       name: httpd
       state: started
     when: ansible_distribution == "CentOS"
 
   - name: install apache2 package (Ubuntu)
     tags: apache,apache2,ubuntu
     apt:
       name:
         - apache2
         - libapache2-mod-php
       state: latest
     when: ansible_distribution == "Ubuntu"
 
   - name: copy html file for site
     tags: apache,apache,apache2,httpd
     copy:
       src: default_site.html
       dest: /var/www/html/index.html
       owner: root
       group: root
       mode: 0644
 
 - hosts: db_servers
   become: true
   tasks:
 
   - name: install mariadb server package (CentOS)
     tags: centos,db,mariadb
     dnf:
       name: mariadb
       state: latest
     when: ansible_distribution == "CentOS"
 
   - name: install mariadb server
     tags: db,mariadb,ubuntu
     apt:
       name: mariadb-server
       state: latest
     when: ansible_distribution == "Ubuntu"
 
 - hosts: file_servers
   tags: samba
   become: true
   tasks:
 
   - name: install samba package
     tags: samba
     package:
       name: samba
       state: latest

site.yml (second version, the change is in bold)

 ---
 
 - hosts: all
   become: true
   pre_tasks:
 
   - name: install updates (CentOS)
     tags: always
     dnf:
       update_only: yes
       update_cache: yes
     when: ansible_distribution == "CentOS"
 
   - name: install updates (Ubuntu)
     tags: always
     apt:
       upgrade: dist
       update_cache: yes
     when: ansible_distribution == "Ubuntu"
 
 - hosts: workstations
   become: true
   tasks:
 
   - name: install unzip
     package:
       name: unzip
 
   - name: install terraform
     unarchive:
       src: https://releases.hashicorp.com/terraform/0.12.28/terraform_0.12.28_linux_amd64.zip
       dest: /usr/local/bin
       remote_src: yes
       mode: 0755
       owner: root
       group: root
 
 - hosts: web_servers
   become: true
   tasks:
 
   - name: install httpd package (CentOS)
     tags: apache,centos,httpd
     dnf:
       name:
         - httpd
         - php
       state: latest
     when: ansible_distribution == "CentOS"
 
   - name: start and enable httpd (CentOS)
     tags: apache,centos,httpd
     service:
       name: httpd
       state: started
       enabled: yes
     when: ansible_distribution == "CentOS"
 
   - name: install apache2 package (Ubuntu)
     tags: apache,apache2,ubuntu
     apt:
       name:
         - apache2
         - libapache2-mod-php
       state: latest
     when: ansible_distribution == "Ubuntu"
 
   - name: copy html file for site
     tags: apache,apache,apache2,httpd
     copy:
       src: default_site.html
       dest: /var/www/html/index.html
       owner: root
       group: root
       mode: 0644
 
 - hosts: db_servers
   become: true
   tasks:
 
   - name: install mariadb server package (CentOS)
     tags: centos,db,mariadb
     dnf:
       name: mariadb
       state: latest
     when: ansible_distribution == "CentOS"
 
   - name: install mariadb server
     tags: db,mariadb,ubuntu
     apt:
       name: mariadb-server
       state: latest
     when: ansible_distribution == "Ubuntu"
 
 - hosts: file_servers
   tags: samba
   become: true
   tasks:
 
   - name: install samba package
     tags: samba
     package:
       name: samba
       state: latest

site.yml (added ‘lineinfile’ play)

 ---
 
 - hosts: all
   become: true
   pre_tasks:
 
   - name: install updates (CentOS)
     tags: always
     dnf:
       update_only: yes
       update_cache: yes
     when: ansible_distribution == "CentOS"
 
   - name: install updates (Ubuntu)
     tags: always
     apt:
       upgrade: dist
       update_cache: yes
     when: ansible_distribution == "Ubuntu"
 
 - hosts: workstations
   become: true
   tasks:
 
   - name: install unzip
     package:
       name: unzip
 
   - name: install terraform
     unarchive:
       src: https://releases.hashicorp.com/terraform/0.12.28/terraform_0.12.28_linux_amd64.zip
       dest: /usr/local/bin
       remote_src: yes
       mode: 0755
       owner: root
       group: root
 
 - hosts: web_servers
   become: true
   tasks:
 
   - name: install httpd package (CentOS)
     tags: apache,centos,httpd
     dnf:
       name:
         - httpd
         - php
       state: latest
     when: ansible_distribution == "CentOS"
 
   - name: start and enable httpd (CentOS)
     tags: apache,centos,httpd
     service:
       name: httpd
       state: started
       enabled: yes
     when: ansible_distribution == "CentOS"
 
   - name: install apache2 package (Ubuntu)
     tags: apache,apache2,ubuntu
     apt:
       name:
         - apache2
         - libapache2-mod-php
       state: latest
     when: ansible_distribution == "Ubuntu"
 
   - name: change e-mail address for admin
     tags: apache,centos,httpd
     lineinfile:
       path: /etc/httpd/conf/httpd.conf
       regexp: '^ServerAdmin'
       line: ServerAdmin somebody@somewhere.net
     when: ansible_distribution == "CentOS"
     register: httpd
 
   - name: restart httpd (CentOS)
     tags: apache,centos,httpd
     service:
       name: httpd
       state: restarted
     when: httpd.changed 
 
   - name: copy html file for site
     tags: apache,apache,apache2,httpd
     copy:
       src: default_site.html
       dest: /var/www/html/index.html
       owner: root
       group: root
       mode: 0644
 
 - hosts: db_servers
   become: true
   tasks:
 
   - name: install mariadb server package (CentOS)
     tags: centos,db,mariadb
     dnf:
       name: mariadb
       state: latest
     when: ansible_distribution == "CentOS"
 
   - name: install mariadb server
     tags: db,mariadb,ubuntu
     apt:
       name: mariadb-server
       state: latest
     when: ansible_distribution == "Ubuntu"
 
 - hosts: file_servers
   tags: samba
   become: true
   tasks:
 
   - name: install samba package
     tags: samba
     package:
       name: samba
       state: latest