Fix passwords.yml generation with vault encryption on Python 3

Kayobe generates passwords.yml for Kolla Ansible, and can encrypt it
using the vault password. Previously this was failing on Python 3 due to
passing a string to file.write() which expects bytes.

This change fixes the issue by encoding the password string passed to
file.write().

This allows us to run the ansible role tests under Python 3.

Change-Id: I33813f79984a46f1967ef3aee455dcfbe7eb93da
Story: 2006574
Task: 39481

ansible/roles/kolla-ansible/library/kolla_passwords.py

@@ -57,7 +57,7 @@ def kolla_mergepwd(module, old_path, new_path, final_path):
 def create_vault_password_file(module):
     """Create a vault password file."""
     with tempfile.NamedTemporaryFile(delete=False) as f:
-        f.write(module.params['vault_password'])
+        f.write(module.params['vault_password'].encode())
         return f.name
 
 

tox.ini

@@ -49,10 +49,6 @@ deps =
 commands = {posargs}
 
 [testenv:ansible]
-# FIXME(mgoddard): Ansible playbooks do not yet support Python 3, so we need to run these
-# tests using Python 2 for the time being.
-basepython = python2
-usedevelop = True
 # Create the virtualenv with access to system site packages, as this is
 # required to use the python and apt modules, which are not available via PyPI.
 sitepackages = True

zuul.d/jobs.yaml

@@ -21,8 +21,6 @@
       tox_envlist: ansible
     required-projects:
       - name: openstack/requirements
-        # TODO(mgoddard): Remove when Ansible playbooks support Python 3.
-        override-checkout: stable/train
     irrelevant-files:
       - ^.*\.rst$
       - ^doc/.*