Add support for global molecule configuration

This patch adds the support for global molecule configuration at the
project level. It detects if a `.config/molecule/config.yml` file exists
at the root of the project and allows us to determine the driver name if
the scenarios configuration files didn't override the default one coming
from the global one.

Fixes #88

Signed-off-by: Gael Chamoulaud (Strider) <gchamoul@redhat.com>

src/tox_ansible/ansible/__init__.py

@@ -13,6 +13,8 @@
 from ..tox_molecule_case import ToxMoleculeCase
 from .scenario import Scenario
 
+LOCAL_CONFIG_FILE = ".config/molecule/config.yml"
+
 
 class Ansible(object):
     """A generalized class that handles interactions between the plugin and
@@ -44,6 +46,26 @@ def is_ansible(self):
             path.join(self.directory, "galaxy.yml")
         )
 
+    @property
+    def is_global_molecule_config(self):
+        """Determine if there is a shared molecule configuration file at the
+        project level.
+
+        :return: The path of the <project>/.config/molecule/config.yml file.
+                 None, otherwise."""
+        config_file_path = path.join(self.directory, LOCAL_CONFIG_FILE)
+        if path.isfile(config_file_path):
+            return config_file_path
+        return None
+
+    @property
+    def molecule_global_config(self):
+        """Reads the .config/molecule/config.yml file if it exists. Adds it to
+        the self.molecule_global_config field."""
+        if self.is_global_molecule_config:
+            return load_yaml(self.is_global_molecule_config)
+        return None
+
     @property
     def scenarios(self):
         """Recursively searches the potential Ansible directory and looks for any
@@ -74,7 +96,9 @@ def scenarios(self):
                 if branch in self.options.ignore_paths:
                     ignored = True
             if not ignored:
-                self._scenarios.append(Scenario(path.relpath(base_dir, self.directory)))
+                self._scenarios.append(Scenario(path.relpath(base_dir,
+                                                             self.directory),
+                                                self.molecule_global_config))
         return self._scenarios
 
     @property

src/tox_ansible/ansible/scenario.py

@@ -6,9 +6,10 @@
 class Scenario(object):
     """Knows about scenarios."""
 
-    def __init__(self, directory):
+    def __init__(self, directory, global_config=None):
         self.directory = directory
         self.scenario_file = path.join(self.directory, "molecule.yml")
+        self.global_config = global_config
 
     def __str__(self):
         return "{}".format(self.name)
@@ -32,10 +33,15 @@ def name(self):
     @property
     def driver(self):
         """Reads the driver for this scenario, if one is defined.
+        If there is no driver found in the scenario configuration and if there
+        is a global configuration, the driver coming from the global
+        configuration will be taken
 
         :return: Driver name defined in molecule.yml or None"""
         if self.config and "driver" in self.config and "name" in self.config["driver"]:
             return self.config["driver"]["name"]
+        elif self.global_config:
+            return self.global_config["driver"]["name"]
         return None
 
     @property

tests/test_scenario.py

@@ -52,3 +52,10 @@ def test_no_driver(no_driver):
     s = Scenario(no_driver)
     assert s.name == "no_driver"
     assert s.driver is None
+
+
+def test_no_driver_with_global_config(no_driver):
+    global_config = {'driver': {'name': 'podman'}}
+    s = Scenario(no_driver, global_config)
+    assert s.name == "no_driver"
+    assert s.driver == "podman"