How do you set up a confirmation prompt before running a task in a playbook?

Question

I want to install MariaDB after confirming user. I have a role and one simple task:

- name: install MariaDB
  yum:
    name: MariaDB
    state: present

or if I want to use include: MySQL.yml, if the user wants to, this line executes, if not skip this include.

- name: install MariaDB
  yum:
    name: MariaDB
    state: present

- include: MySQL.yml

more explain

my hosts:

[dbs]
192.168.0.10
192.168.0.11
192.168.0.12

Now, I want if the user enters no for answer prompt, MySQL.yml does not execute for any server.

my code in role (tasks/main.yml):

---
- pause:
   prompt: "Do you want to install mariadb (yes/no)?"
  register: my_pause
  delegate_to: localhost

- include_tasks: mysql.yml
  when: hostvars['localhost'].my_pause.user_input | bool

and my output :

[root@anisble ansible]# ansible-playbook playbooks/test.yml 



PLAY [dbs] 
********************************************************************

TASK [Gathering Facts] ******************************************************************
ok: [db1]
ok: [db2]
ok: [db3]

TASK [ssh : pause] ******************************************************************************
[ssh : pause]
Do you want to install mariadb (yes/no)?:
no
  ok: [db1 -> localhost]

TASK [ssh : include_tasks] ***********************************************************************************
included: /etc/ansible/roles/ssh/tasks/mysql.yml for db1, db2, db3

TASK [ssh : install mariadb] ******************************************************************************
ok: [db3]
ok: [db2]
ok: [db1]

PLAY RECAP *****************************************************************************
db1                        : ok=4    changed=0    unreachable=0    failed=0   
db2                        : ok=3    changed=0    unreachable=0    failed=0   
db3                        : ok=3    changed=0    unreachable=0    failed=0  

Answer 1

You can use either a variable prompt or pause module with user_input; and set up a condition for the task:

- hosts: my_host_group

  vars_prompt:
    - name: "install_mariadb"
      prompt: "Do you want to install MariaDB (yes/no)?"
      private: no

  tasks:
    - name: install MariaDB
      yum:
        name: MariaDB
        state: present
      when: install_mariadb | bool

    - include_tasks: MySQL.yml
      when: install_mariadb | bool

or

- hosts: my_host_group

  tasks:
    - pause:
        prompt: "Do you want to install MariaDB (yes/no)?"
      register: my_pause
      delegate_to: localhost

    - name: install MariaDB
      yum:
        name: MariaDB
        state: present
      when: hostvars['localhost'].my_pause.user_input | bool

    - include_tasks: MySQL.yml
      when: hostvars['localhost'].my_pause.user_input | bool