Extend pytest so it can accept ansible args

This change adds the ability add ansible arguments to any
molecule test.

Change-Id: I7159e89d7037b2c669208014d4f814de2eb6f1ad
Signed-off-by: Kevin Carter <kecarter@redhat.com>

releasenotes/notes/add-ansible-args-to-test-commands-e6b14d561af5de7d.yaml

@@ -0,0 +1,11 @@
+---
+features:
+  - |
+    A new argument has been added to the molecule test setup allowing
+    developers to run tests with Ansible command line arguments. This
+    feature is useful when testing roles that require augmentation,
+    like when tags are needed.
+
+    .. code-block:: console
+
+        pytest tests/test_molecule.py --scenario=${NEWROLENAME} --ansible-args='--tags xxx --skip-tags yyy'

tests/conftest.py

@@ -17,3 +17,4 @@ import os
 
 def pytest_addoption(parser):
     parser.addoption('--scenario', help='scenario setting')
+    parser.addoption('--ansible-args', help='ansible args passed into test runner.')

tests/test_molecule.py

@@ -18,11 +18,28 @@ import pytest
 
 
 def test_molecule(pytestconfig):
-    cmd = ['python', '-m', 'molecule', 'test']
+    cmd = ['python', '-m', 'molecule']
     scenario = pytestconfig.getoption("scenario")
+    ansible_args = pytestconfig.getoption("ansible_args")
+
+    if ansible_args:
+        cmd.append('converge')
+        if scenario:
+            cmd.extend(['--scenario-name', scenario])
+        cmd.append('--')
+        cmd.extend(ansible_args.split())
+    else:
+        cmd.append('test')
         if scenario:
             cmd.extend(['--scenario-name', scenario])
         else:
             cmd.append('--all')
 
+    try:
         assert subprocess.call(cmd) == 0
+    finally:
+        if ansible_args:
+            cmd = ['python', '-m', 'molecule', 'destroy']
+            if scenario:
+                cmd.extend(['--scenario-name', scenario])
+            subprocess.call(cmd)