Targeting-Specific-Node.md

LAB: Targeting Specific Nodes

This scenario shows:

• how to target specific nodes

Prerequisite

• You should have a look following lab, nodes that are created in that LAB, are using in ansible commands
  • LAB: Multipass-SSH Configuration (Create Ansible Test Environment)

Steps

• Update inventory file.
• Make groups by giving names with '[]'.

[web_servers]
172.21.79.85

[database_servers]
172.21.76.101

• Create 'site.yml' file
• To prioritize the tasks, for updating, 'pre_tasks' is used
• For different hosts, 3 different host groups are created: all, web_servers and database_servers

---

- hosts: all
  become: true
  pre_tasks:

  - name: install updates (CentOS)
    dnf:
      update_only: yes
      update_cache: yes
    when: ansible_distribution == "CentOS"

  - name: install updates (Ubuntu)
    apt:
      upgrade: dist
      update_cache: yes
    when: ansible_distribution == "Ubuntu"

- hosts: web_servers
  become: true
  tasks:

  - name: install apache and php (CentOS)
    dnf:
      name:
        - httpd
        - php
      state: latest
    when: ansible_distribution == "CentOS"

  - name: install apache and php (Ubuntu)
    apt:
      name:
        - apache2
        - libapache2-mod-php
      state: latest
    when: ansible_distribution == "Ubuntu"
    
- hosts: database_servers
  become: true
  tasks:

  - name: install MariaDB (CentOS)
    dnf:
      name: mariadb
      state: latest
    when: ansible_distribution == "CentOS"

  - name: install MariaDB (Ubuntu)
    apt:
      name: mariadb-server
      state: latest
    when: ansible_distribution == "Ubuntu"

• Run

ansible-playbook --ask-become-pass site.yml

• When we control whether mariadb is installed or not on database_servers (node2), it can be seen that it was installed on node2.

multipass shell node2
systemctl status mariadb