Ansible vault: a framework for encrypting any playbook or var file.

```
$ ansible-vault --help
Usage: ansible-vault [create|decrypt|edit|encrypt|rekey] [--help] [options] file_name

Options:
  -h, --help  show this help message and exit

See 'ansible-vault <command> --help' for more information on a specific command.
```

* create: start a new encrypted file
* decrypt: unencrypt file(s) in place
* edit: open an encrypted file in the default editor
* encrypt: encrypt file(s) in place
* rekey: decrypt with previous password, re-encrypt with new password

```
$ ansible-playbook -i inventory site.yml --ask-vault-pass
Vault password:
```