Fixing role dependency chain creation

The dep chain for roles created during the compile step had bugs, in
which the dep chain was overwriten and the original tasks in the role
were not assigned a dep chain. This lead to problems in determining
whether roles had already run when in a "diamond" structure, and in
some cases roles were not correctly getting variables from parents.

Fixes #14046

lib/ansible/executor/play_iterator.py

@@ -49,6 +49,7 @@ class HostState:
         self.cur_rescue_task    = 0
         self.cur_always_task    = 0
         self.cur_role           = None
+        self.cur_dep_chain      = None
         self.run_state          = PlayIterator.ITERATING_SETUP
         self.fail_state         = PlayIterator.FAILED_NONE
         self.pending_setup      = False
@@ -102,6 +103,8 @@ class HostState:
         new_state.run_state        = self.run_state
         new_state.fail_state       = self.fail_state
         new_state.pending_setup    = self.pending_setup
+        if self.cur_dep_chain is not None:
+            new_state.cur_dep_chain = self.cur_dep_chain[:]
         if self.tasks_child_state is not None:
             new_state.tasks_child_state = self.tasks_child_state.copy()
         if self.rescue_child_state is not None:
@@ -212,13 +215,21 @@ class PlayIterator:
                 s.pending_setup = False
 
         if not task:
+            old_s = s
             (s, task) = self._get_next_task_from_state(s, peek=peek)
 
+        def _roles_are_different(ra, rb):
+            if ra != rb:
+                return True
+            else:
+                return old_s.cur_dep_chain != task._block._dep_chain
+
         if task and task._role:
             # if we had a current role, mark that role as completed
-            if s.cur_role and task._role != s.cur_role and host.name in s.cur_role._had_task_run and not peek:
+            if s.cur_role and _roles_are_different(task._role, s.cur_role) and host.name in s.cur_role._had_task_run and not peek:
                 s.cur_role._completed[host.name] = True
             s.cur_role = task._role
+            s.cur_dep_chain = task._block._dep_chain
 
         if not peek:
             self._host_states[host.name] = s

lib/ansible/playbook/role/__init__.py

@@ -323,7 +323,7 @@ class Role(Base, Become, Conditional, Taggable):
 
         return host.name in self._completed and not self._metadata.allow_duplicates
 
-    def compile(self, play, dep_chain=[]):
+    def compile(self, play, dep_chain=None):
         '''
         Returns the task list for this role, which is created by first
         recursively compiling the tasks for all direct dependencies, and
@@ -337,18 +337,20 @@ class Role(Base, Become, Conditional, Taggable):
         block_list = []
 
         # update the dependency chain here
+        if dep_chain is None:
+            dep_chain = []
         new_dep_chain = dep_chain + [self]
 
         deps = self.get_direct_dependencies()
         for dep in deps:
             dep_blocks = dep.compile(play=play, dep_chain=new_dep_chain)
-            for dep_block in dep_blocks:
+            block_list.extend(dep_blocks)
-                new_dep_block = dep_block.copy()
-                new_dep_block._dep_chain = new_dep_chain
-                new_dep_block._play = play
-                block_list.append(new_dep_block)
 
-        block_list.extend(self._task_blocks)
+        for task_block in self._task_blocks:
+            new_task_block = task_block.copy()
+            new_task_block._dep_chain = new_dep_chain
+            new_task_block._play = play
+            block_list.append(new_task_block)
 
         return block_list
 

test/integration/roles/test_var_precedence_dep/tasks/main.yml

@@ -7,7 +7,7 @@
 - assert:
     that:
       - 'extra_var == "extra_var"'
-      - 'param_var == "param_var"'
+      - 'param_var == "param_var_role1"'
       - 'vars_var == "vars_var"'
       - 'vars_files_var == "vars_files_var"'
       - 'vars_files_var_role == "vars_files_var_dep"'