What is Ansible's config equivalent of `--vault-password-file`?
Here is the definition:

DEFAULT_VAULT_PASSWORD_FILE = get_config(p, DEFAULTS, 'vault_password_file', \
'ANSIBLE_VAULT_PASSWORD_FILE', None, value_type='path')




This means that you either put in ansible.cfg or playbook:

vault_password_file: ~/.vault_pass.txt


Or in your shell defined this variable:

export ANSIBLE_VAULT_PASSWORD_FILE=~/.vault_pass.txt