Install & SSH set up

sudo dnf install ansible

ssh-keygen

ssh-copy-id USER_NAME@HOST_NAME

Ansible Inventory File

# Localhost 
[localhost]
127.0.0.1

# Matches from server01 to server20
server[01:20].example.com

# Group named 'webservers' with two servers
[webservers]
webserver1.example.com
webserver2.example.com

# Nested group  'backend' under the 'webservers' group
[webservers:backend]
dbserver.example.com

Execute command

ansible <host-pattern> -m shell -a "<command>"

Browse Inventory

ansible-navigator inventory

Sample ansible.cfg

[defaults]
inventory = ./inventory
remote_user = someuser
ask_pass = false
[privilege_escalation]
become = true
become_method = sudo
become_user = root
become_ask_pass = false

Run Playbook

ansible-navigator run  -m stdout ping-all.yml

Playbook Dry run

ansible-navigator run -m stdout webserver.yml --check

Pass variables to a Playbook

ansible-navigator run main.yml -e "package=jboss"

Encrypt file

ansible-vault create secret.yml                    

View Encrypted file

ansible-vault view secret1.yml  

Check Service Started

ansible <host-pattern> -m service -a "name=<service_name> state=started"

Playbook Structure

---
- name: Playbook Name
  hosts: <host-pattern>
  become: <true/false>
  tasks:
    - name: Task Name
      <module>: <arguments>

PlayBook Variables

---
- name: Playbook with Variable
  hosts: localhost
  vars:
    my_variable: "Hello, world!"

  tasks:
    - name: Print Playbook Variable
      debug:
        msg: "{{ my_variable }}"

Capture output

---
- name: Capture output
  hosts: all
  tasks:
    - name: Install the package
      ansible.builtin.dnf:
        name: httpd
        state: installed
      register: install_result

    - debug:
        var: install_result

Conditional execution

---
- name: Conditional Execution
  hosts: all
  tasks:
    - name: Ensure a directory exists
      file:
        path: /path/to/directory
        state: directory
      when: ansible_os_family == "RedHat"

Loop execution

---
- name: Playbook with Loop
  hosts: all
  vars:
    packages_to_install:
      - vim
      - git
      - curl
  tasks:
    - name: Install required packages
      yum:
        name: "{{ item }}"
        state: present
      loop: "{{ packages_to_install }}"

Handler

---
- name: Playbook with Handler
  hosts: all
  tasks:
    - name: Ensure a file exists
      file:
        path: /path/to/file
        state: touch
      notify: restart service

  handlers:
    - name: restart service
      service:
        name: myservice
        state: restarted

Init a Role

ansible-galaxy init my_new_role

Use Role

---
- name: Playbook with Role
  hosts: all
  roles:
    - webserver

Role from Requirements

ansible-galaxy role install -r roles/requirements.yml -p roles

List Roles

ansible-galaxy list

Search Roles

ansible-galaxy search 'wildfly'

Info Role

ansible-galaxy-info 'role'

Jinja2 Template

---
- name: Playbook with Jinja2 Template
  hosts: all
  tasks:
    - name: Render Jinja2 Template
      template:
        src: path/to/my_template.j2
        dest: /path/to/output/file
      vars:
        variable_name: value

{% for item in my_list %}
Item: {{ item }}
{% endfor %}

Conditionals

{% if ansible_os_family == 'RedHat' %}
RedHat specific tasks
{% endif %}

Use Facts

Ansible OS: {{ ansible_facts.os_family }}

Variables

My variable value: {{ my_variable }}