Install Ansible on Ubuntu 20.04 and run ansible-playbook

1. create user ID and sudo rules
   create ID ansible on all Linux:
   sudo adduser ansible
   echo "ansible ALL=(ALL) NOPASSWD:ALL" | sudo tee /etc/sudoers.d/ansible
2. generate SSH key and copy to client servers:
   ssh-keygen
   ssh-copy-id ansible@192.168.0.143
   ssh-copy-id ansible@192.168.0.61
3. install ansible:
   sudo apt update
   sudo apt install ansible
4. add client servers:
   sudo vi /etc/ansible/hosts
   [servers]
   server1 ansible_host=192.168.0.143
   server2 ansible_host=192.168.0.61
5. verify ansible hosts and run playbook
   sudo ansible-inventory –list -y
   mkdir ~/ansible-demo
   create few ansible-playbook in ~/ansible-demo:

   
   ansible@ubunu2004:~/ansible-demo$ cat install-apt.yml
   ---
   - hosts: all
   become: yes
   tasks:
   - name: Install packages
   apt:
     name:
     - ntpdate
     - nmap
     state: latest
     cache_valid_time: 3600
   ansible@ubunu2004:~/ansible-demo$ cat linux-echo.yml
   ---
   - hosts: all
   become: yes
   tasks:
   - name: Echo the Date to a tmp file
   shell: echo  "`date`"> /tmp/date
   - name: Echo String to a tmp file
   shell: echo  "Techexpert.tips is a greate website" > /tmp/techexpert

run the playbook:
```bash
ansible@ubunu2004:~/ansible-demo$ ansible-playbook install-apt.yml

PLAY [all] ***************************************************************************************************************************************************************************************************

TASK [Gathering Facts] ***************************************************************************************************************************************************************************************
ok: [server1]
ok: [server2]

TASK [Install packages] **************************************************************************************************************************************************************************************
changed: [server1]
changed: [server2]

PLAY RECAP ***************************************************************************************************************************************************************************************************
server1                    : ok=2    changed=1    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0
server2                    : ok=2    changed=1    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

Ansible Playbook Example – Reading a Variable from the Command-line
This Ansible playbook example named linux-scan.yml will install the Nmap package.
It will read the IP addres from the IP_VAR variable and use NMAP to scan this host.

---
- hosts: all
  become: yes
  tasks:
  - name: Install packages
    apt:
      name:
      - nmap
      state: latest
      cache_valid_time: 3600
  - name: Scan host using nmap
    shell: nmap "{{ ip_var }}"
    register: out

  - debug: var=out.stdout_lines

To run this Ansible playbook, use the following command:
ansible-playbook --extra-vars ip_var=192.168.0.143 linux-scan.yml