Added basic support for hash_behaviour=merge in roles

Dict vars passed to roles are now properly merged
instead of simply overriding dict vars that are
coming from vars_files.

lib/ansible/playbook/play.py

@@ -269,7 +269,7 @@ class Play(object):
                         raise errors.AnsibleError("parse error: task includes cannot be used with other directives: %s" % k)
 
                 if 'vars' in x:
-                    task_vars.update(x['vars'])
+                    task_vars = utils.combine_vars(task_vars, x['vars'])
                 if 'only_if' in x:
                     included_additional_conditions.append(x['only_if'])
 

lib/ansible/utils/__init__.py

@@ -335,24 +335,23 @@ def parse_kv(args):
     return options
 
 def merge_hash(a, b):
-    ''' merges hash b into a
-    this means that if b has key k, the resulting has will have a key k
-    which value comes from b
-    said differently, all key/value combination from b will override a's '''
+    ''' recursively merges hash b into a
+    keys from b take precedende over keys from a '''
 
-    # and iterate over b keys
+    result = copy.deepcopy(a)
+
+    # next, iterate over b keys and values
     for k, v in b.iteritems():
-        if k in a and isinstance(a[k], dict):
-            # if this key is a hash and exists in a
-            # we recursively call ourselves with
-            # the key value of b
-            a[k] = merge_hash(a[k], v)
+        # if there's already such key in a
+        # and that key contains dict
+        if k in result and isinstance(result[k], dict):
+            # merge those dicts recursively
+            result[k] = merge_hash(a[k], v)
         else:
-            # k is not in a, no need to merge b, we just deecopy
-            # or k is not a dictionnary, no need to merge b either, we just deecopy it
-            a[k] = v
-    # finally, return the resulting hash when we're done iterating keys
-    return a
+            # otherwise, just copy a value from b to a
+            result[k] = v
+
+    return result
 
 def md5s(data):
     ''' Return MD5 hex digest of data. '''

test/TestPlayBook.py

@@ -96,6 +96,8 @@ class TestPlaybook(unittest.TestCase):
            os.unlink('/tmp/ansible_test_data_template.out')
        if os.path.exists('/tmp/ansible_test_messages.out'):
            os.unlink('/tmp/ansible_test_messages.out')
+       if os.path.exists('/tmp/ansible_test_role_messages.out'):
+           os.unlink('/tmp/ansible_test_role_messages.out')
 
    def _prepare_stage_dir(self):
        stage_path = os.path.join(self.test_dir, 'test_data')
@@ -304,20 +306,17 @@ class TestPlaybook(unittest.TestCase):
       )
       playbook.run()
 
-      with open('/tmp/ansible_test_messages.out') as f:
-        actual = [l.strip() for l in f.readlines()]
-
-      print "**ACTUAL**"
-      print actual
-
-      expected = [
+      filename = '/tmp/ansible_test_messages.out'
+      expected_lines = [
         "goodbye: Goodbye World!"
       ]
+      self._compare_file_output(filename, expected_lines)
 
-      print "**EXPECTED**"
-      print expected
-
-      assert actual == expected
+      filename = '/tmp/ansible_test_role_messages.out'
+      expected_lines = [
+        "inside_a_role: Indeed!"
+      ]
+      self._compare_file_output(filename, expected_lines)
 
       # restore default hash behavior
       C.DEFAULT_HASH_BEHAVIOUR = saved_hash_behavior
@@ -337,21 +336,34 @@ class TestPlaybook(unittest.TestCase):
       )
       playbook.run()
 
-      with open('/tmp/ansible_test_messages.out') as f:
-        actual = [l.strip() for l in f.readlines()]
-
-      print "**ACTUAL**"
-      print actual
+      filename = '/tmp/ansible_test_messages.out'
+      expected_lines = [
+        "goodbye: Goodbye World!",
+        "hello: Hello World!"
+      ]
+      self._compare_file_output(filename, expected_lines)
 
-      expected = [
+      filename = '/tmp/ansible_test_role_messages.out'
+      expected_lines = [
+        "goodbye: Goodbye World!",
         "hello: Hello World!",
-        "goodbye: Goodbye World!"
+        "inside_a_role: Indeed!"
       ]
-
-      print "**EXPECTED**"
-      print expected
-
-      assert actual == expected
+      self._compare_file_output(filename, expected_lines)
 
       # restore default hash behavior
       C.DEFAULT_HASH_BEHAVIOUR = saved_hash_behavior
+
+   def _compare_file_output(self, filename, expected_lines):
+      actual_lines = []
+      with open(filename) as f:
+        actual_lines = [l.strip() for l in f.readlines()]
+        actual_lines = sorted(actual_lines)
+
+      print "**ACTUAL**"
+      print actual_lines
+
+      print "**EXPECTED**"
+      print expected_lines
+
+      assert actual_lines == expected_lines

test/test_hash_behavior/playbook.yml

@@ -9,3 +9,8 @@
   tasks:
     - name: generate messages
       action: template src=message.j2 dest=/tmp/ansible_test_messages.out
+
+  roles:
+    - role: hash_behavior_test_role
+      messages:
+        inside_a_role: "Indeed!"

test/test_hash_behavior/roles/hash_behavior_test_role/tasks/main.yml

@@ -0,0 +1,2 @@
+- name: generate role messages
+  action: template src=role_message.j2 dest=/tmp/ansible_test_role_messages.out

test/test_hash_behavior/roles/hash_behavior_test_role/templates/role_message.j2

@@ -0,0 +1,3 @@
+{% for k, v in messages.iteritems() %}
+{{ k }}: {{ v }}
+{% endfor %}