AnsibleのPlaybookを作成して実行していると実行前になんらかの変数を入力させたいことがあります。vars_promptを使うと実現できます。

playbook.yml

- name: Test
  hosts: localhost
  vars_prompt:
    - name: "input_var"
      prompt: "INPUT: "
      confirm: no
      private: no
      default: "fish"
  tasks:
    - debug: msg="{{ input_var }}"

beefを指定してみます。

$ .venv/bin/ansible-playbook playbook.yml
 [WARNING]: Host file not found: /etc/ansible/hosts

 [WARNING]: provided hosts list is empty, only localhost is available

INPUT:  [fish]: beef
 _____________
< PLAY [Test] >
 -------------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/                ||----w |
                ||     ||

 ______________
< TASK [setup] >
 --------------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/                ||----w |
                ||     ||

ok: [localhost]
 ______________
< TASK [debug] >
 --------------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/                ||----w |
                ||     ||

ok: [localhost] => {
    "msg": "beef"
}
 ____________
< PLAY RECAP >
 ------------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/                ||----w |
                ||     ||

localhost                  : ok=2    changed=0    unreachable=0    failed=0

指定せずにENTERを押すとデフォルト値が使われます。

$ .venv/bin/ansible-playbook playbook.yml
 [WARNING]: Host file not found: /etc/ansible/hosts

 [WARNING]: provided hosts list is empty, only localhost is available

INPUT:  [fish]:
 _____________
< PLAY [Test] >
 -------------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/                ||----w |
                ||     ||

 ______________
< TASK [setup] >
 --------------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/                ||----w |
                ||     ||

ok: [localhost]
 ______________
< TASK [debug] >
 --------------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/                ||----w |
                ||     ||

ok: [localhost] => {
    "msg": "fish"
}
 ____________
< PLAY RECAP >
 ------------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/                ||----w |
                ||     ||

localhost                  : ok=2    changed=0    unreachable=0    failed=0