Starting to add additional unit tests for VariableManager

Required some rewiring in inventory code to make sure we're using
the DataLoader class for some data file operations, which makes mocking
them much easier.

Also identified two corner cases not currently handled by the code, related
to inventory variable sources and which one "wins". Also noticed we weren't
properly merging variables from multiple group/host_var file locations
(inventory directory vs. playbook directory locations) so fixed as well.

1 files changed, 127 insertions, 7 deletions

diff --git a/test/units/vars/test_variable_manager.py b/test/units/vars/test_variable_manager.py
index 18454bf444..a29f7c075a 100644
--- a/test/units/vars/test_variable_manager.py
+++ b/test/units/vars/test_variable_manager.py
@@ -19,11 +19,13 @@
 from __future__ import (absolute_import, division, print_function)
 __metaclass__ = type
 
+from collections import defaultdict
 from six import iteritems
 
 from ansible.compat.tests import unittest
 from ansible.compat.tests.mock import patch, MagicMock
-
+from ansible.inventory import Inventory
+from ansible.playbook.play import Play
 from ansible.vars import VariableManager
 
 from units.mock.loader import DictDataLoader
@@ -68,20 +70,27 @@ class TestVariableManager(unittest.TestCase):
         fake_loader = DictDataLoader({
             "host_vars/hostname1.yml": """
                foo: bar
-            """
+            """,
+            "other_path/host_vars/hostname1.yml": """
+               foo: bam
+               baa: bat
+            """,
         })
 
         v = VariableManager()
         v.add_host_vars_file("host_vars/hostname1.yml", loader=fake_loader)
+        v.add_host_vars_file("other_path/host_vars/hostname1.yml", loader=fake_loader)
         self.assertIn("hostname1", v._host_vars_files)
-        self.assertEqual(v._host_vars_files["hostname1"], dict(foo="bar"))
+        self.assertEqual(v._host_vars_files["hostname1"], [dict(foo="bar"), dict(foo="bam", baa="bat")])
 
         mock_host = MagicMock()
         mock_host.get_name.return_value = "hostname1"
         mock_host.get_vars.return_value = dict()
         mock_host.get_groups.return_value = ()
+        mock_host.get_group_vars.return_value = dict()
 
-        self.assertEqual(v.get_vars(loader=fake_loader, host=mock_host, use_cache=False).get("foo"), "bar")
+        self.assertEqual(v.get_vars(loader=fake_loader, host=mock_host, use_cache=False).get("foo"), "bam")
+        self.assertEqual(v.get_vars(loader=fake_loader, host=mock_host, use_cache=False).get("baa"), "bat")
 
     def test_variable_manager_group_vars_file(self):
         fake_loader = DictDataLoader({
@@ -90,15 +99,19 @@ class TestVariableManager(unittest.TestCase):
             """,
             "group_vars/somegroup.yml": """
                bam: baz
+            """,
+            "other_path/group_vars/somegroup.yml": """
+               baa: bat
             """
         })
 
         v = VariableManager()
         v.add_group_vars_file("group_vars/all.yml", loader=fake_loader)
         v.add_group_vars_file("group_vars/somegroup.yml", loader=fake_loader)
+        v.add_group_vars_file("other_path/group_vars/somegroup.yml", loader=fake_loader)
         self.assertIn("somegroup", v._group_vars_files)
-        self.assertEqual(v._group_vars_files["all"], dict(foo="bar"))
-        self.assertEqual(v._group_vars_files["somegroup"], dict(bam="baz"))
+        self.assertEqual(v._group_vars_files["all"], [dict(foo="bar")])
+        self.assertEqual(v._group_vars_files["somegroup"], [dict(bam="baz"), dict(baa="bat")])
 
         mock_group = MagicMock()
         mock_group.name = "somegroup"
@@ -109,10 +122,11 @@ class TestVariableManager(unittest.TestCase):
         mock_host.get_name.return_value = "hostname1"
         mock_host.get_vars.return_value = dict()
         mock_host.get_groups.return_value = (mock_group,)
+        mock_host.get_group_vars.return_value = dict()
 
         vars = v.get_vars(loader=fake_loader, host=mock_host, use_cache=False)
         self.assertEqual(vars.get("foo"), "bar")
-        self.assertEqual(vars.get("bam"), "baz")
+        self.assertEqual(vars.get("baa"), "bat")
 
     def test_variable_manager_play_vars(self):
         fake_loader = DictDataLoader({})
@@ -150,3 +164,109 @@ class TestVariableManager(unittest.TestCase):
         v = VariableManager()
         self.assertEqual(v.get_vars(loader=fake_loader, task=mock_task, use_cache=False).get("foo"), "bar")
 
+    def test_variable_manager_precedence(self):
+        '''
+        Tests complex variations and combinations of get_vars() with different
+        objects to modify the context under which variables are merged.
+        '''
+
+        v = VariableManager()
+        v._fact_cache = defaultdict(dict)
+
+        fake_loader = DictDataLoader({
+            # inventory1
+            '/etc/ansible/inventory1': """
+            [group2:children]
+            group1
+
+            [group1]
+            host1 host_var=host_var_from_inventory_host1
+
+            [group1:vars]
+            group_var = group_var_from_inventory_group1
+
+            [group2:vars]
+            group_var = group_var_from_inventory_group2
+            """,
+
+            # role defaults_only1
+            '/etc/ansible/roles/defaults_only1/defaults/main.yml': """
+            default_var: "default_var_from_defaults_only1"
+            host_var: "host_var_from_defaults_only1"
+            group_var: "group_var_from_defaults_only1"
+            group_var_all: "group_var_all_from_defaults_only1"
+            extra_var: "extra_var_from_defaults_only1"
+            """,
+            '/etc/ansible/roles/defaults_only1/tasks/main.yml': """
+            - debug: msg="here i am"
+            """,
+
+            # role defaults_only2
+            '/etc/ansible/roles/defaults_only2/defaults/main.yml': """
+            default_var: "default_var_from_defaults_only2"
+            host_var: "host_var_from_defaults_only2"
+            group_var: "group_var_from_defaults_only2"
+            group_var_all: "group_var_all_from_defaults_only2"
+            extra_var: "extra_var_from_defaults_only2"
+            """,
+        })
+
+        inv1 = Inventory(loader=fake_loader, variable_manager=v, host_list='/etc/ansible/inventory1')
+        inv1.set_playbook_basedir('./')
+
+        play1 = Play.load(dict(
+           hosts=['all'],
+           roles=['defaults_only1', 'defaults_only2'],
+        ), loader=fake_loader, variable_manager=v)
+
+        # first we assert that the defaults as viewed as a whole are the merged results
+        # of the defaults from each role, with the last role defined "winning" when
+        # there is a variable naming conflict
+        res = v.get_vars(loader=fake_loader, play=play1)
+        self.assertEqual(res['default_var'], 'default_var_from_defaults_only2')
+
+        # next, we assert that when vars are viewed from the context of a task within a
+        # role, that task will see its own role defaults before any other role's
+        blocks = play1.compile()
+        task = blocks[1].block[0]
+        res = v.get_vars(loader=fake_loader, play=play1, task=task)
+        self.assertEqual(res['default_var'], 'default_var_from_defaults_only1')
+
+        # next we assert the precendence of inventory variables
+        v.set_inventory(inv1)
+        h1 = inv1.get_host('host1')
+
+        res = v.get_vars(loader=fake_loader, play=play1, host=h1)
+        self.assertEqual(res['group_var'], 'group_var_from_inventory_group1')
+        self.assertEqual(res['host_var'], 'host_var_from_inventory_host1')
+
+        # next we test with group_vars/ files loaded
+        fake_loader.push("/etc/ansible/group_vars/all", """
+        group_var_all: group_var_all_from_group_vars_all
+        """)
+        fake_loader.push("/etc/ansible/group_vars/group1", """
+        group_var: group_var_from_group_vars_group1
+        """)
+        fake_loader.push("/etc/ansible/group_vars/group3", """
+        # this is a dummy, which should not be used anywhere
+        group_var: group_var_from_group_vars_group3
+        """)
+        fake_loader.push("/etc/ansible/host_vars/host1", """
+        host_var: host_var_from_host_vars_host1
+        """)
+
+        v.add_group_vars_file("/etc/ansible/group_vars/all", loader=fake_loader)
+        v.add_group_vars_file("/etc/ansible/group_vars/group1", loader=fake_loader)
+        v.add_group_vars_file("/etc/ansible/group_vars/group2", loader=fake_loader)
+        v.add_host_vars_file("/etc/ansible/host_vars/host1", loader=fake_loader)
+
+        res = v.get_vars(loader=fake_loader, play=play1, host=h1)
+        self.assertEqual(res['group_var'], 'group_var_from_group_vars_group1')
+        self.assertEqual(res['group_var_all'], 'group_var_all_from_group_vars_all')
+        self.assertEqual(res['host_var'], 'host_var_from_host_vars_host1')
+
+        # add in the fact cache
+        v._fact_cache['host1'] = dict(fact_cache_var="fact_cache_var_from_fact_cache")
+
+        res = v.get_vars(loader=fake_loader, play=play1, host=h1)
+        self.assertEqual(res['fact_cache_var'], 'fact_cache_var_from_fact_cache')