Merge remote-tracking branch 'origin/602-recover-taskvars'

* origin/602-recover-taskvars:
  issue #602: update Changelog
  issue #602: recover task_vars for synchronize and meta: reset_connection
  ansible: remove cutpasted docstring
  [linear2] merge fallout: restore optimization from #491 / 7b129e857

ansible_mitogen/connection.py

@@ -46,6 +46,7 @@ import mitogen.core
 import mitogen.fork
 import mitogen.utils
 
+import ansible_mitogen.mixins
 import ansible_mitogen.parsing
 import ansible_mitogen.process
 import ansible_mitogen.services
@@ -405,15 +406,6 @@ CONNECTION_METHOD = {
 }
 
 
-class Broker(mitogen.master.Broker):
-    """
-    WorkerProcess maintains at most 2 file descriptors, therefore does not need
-    the exuberant syscall expense of EpollPoller, so override it and restore
-    the poll() poller.
-    """
-    poller_class = mitogen.core.Poller
-
-
 class CallChain(mitogen.parent.CallChain):
     """
     Extend :class:`mitogen.parent.CallChain` to additionally cause the
@@ -542,6 +534,47 @@ class Connection(ansible.plugins.connection.ConnectionBase):
         self.loader_basedir = loader_basedir
         self._mitogen_reset(mode='put')
 
+    def _get_task_vars(self):
+        """
+        More information is needed than normally provided to an Ansible
+        connection.  For proxied connections, intermediary configuration must
+        be inferred, and for any connection the configured Python interpreter
+        must be known.
+
+        There is no clean way to access this information that would not deviate
+        from the running Ansible version. The least invasive method known is to
+        reuse the running task's task_vars dict.
+
+        This method walks the stack to find task_vars of the Action plugin's
+        run(), or if no Action is present, from Strategy's _execute_meta(), as
+        in the case of 'meta: reset_connection'. The stack is walked in
+        addition to subclassing Action.run()/on_action_run(), as it is possible
+        for new connections to be constructed in addition to the preconstructed
+        connection passed into any running action.
+        """
+        f = sys._getframe()
+
+        while f:
+            if f.f_code.co_name == 'run':
+                f_locals = f.f_locals
+                f_self = f_locals.get('self')
+                if isinstance(f_self, ansible_mitogen.mixins.ActionModuleMixin):
+                    task_vars = f_locals.get('task_vars')
+                    if task_vars:
+                        LOG.debug('recovered task_vars from Action')
+                        return task_vars
+            elif f.f_code.co_name == '_execute_meta':
+                f_all_vars = f.f_locals.get('all_vars')
+                if isinstance(f_all_vars, dict):
+                    LOG.debug('recovered task_vars from meta:')
+                    return f_all_vars
+
+            f = f.f_back
+
+        LOG.warning('could not recover task_vars. This means some connection '
+                    'settings may erroneously be reset to their defaults. '
+                    'Please report a bug if you encounter this message.')
+
     def get_task_var(self, key, default=None):
         """
         Fetch the value of a task variable related to connection configuration,
@@ -553,12 +586,13 @@ class Connection(ansible.plugins.connection.ConnectionBase):
         does not make sense to extract connection-related configuration for the
         delegated-to machine from them.
         """
-        if self._task_vars:
+        task_vars = self._task_vars or self._get_task_vars()
+        if task_vars is not None:
             if self.delegate_to_hostname is None:
-                if key in self._task_vars:
+                if key in task_vars:
-                    return self._task_vars[key]
+                    return task_vars[key]
             else:
-                delegated_vars = self._task_vars['ansible_delegated_vars']
+                delegated_vars = task_vars['ansible_delegated_vars']
                 if self.delegate_to_hostname in delegated_vars:
                     task_vars = delegated_vars[self.delegate_to_hostname]
                     if key in task_vars:

ansible_mitogen/parsing.py

@@ -26,14 +26,6 @@
 # ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 # POSSIBILITY OF SUCH DAMAGE.
 
-"""
-Classes to detect each case from [0] and prepare arguments necessary for the
-corresponding Runner class within the target, including preloading requisite
-files/modules known missing.
-
-[0] "Ansible Module Architecture", developing_program_flow_modules.html
-"""
-
 from __future__ import absolute_import
 from __future__ import unicode_literals
 

ansible_mitogen/process.py

@@ -294,6 +294,15 @@ def get_cpu_count(default=None):
     return cpu_count
 
 
+class Broker(mitogen.master.Broker):
+    """
+    WorkerProcess maintains at most 2 file descriptors, therefore does not need
+    the exuberant syscall expense of EpollPoller, so override it and restore
+    the poll() poller.
+    """
+    poller_class = mitogen.core.Poller
+
+
 class Binding(object):
     """
     Represent a bound connection for a particular inventory hostname. When
@@ -530,7 +539,7 @@ class ClassicWorkerModel(WorkerModel):
         See WorkerModel.get_binding().
         """
         if self.broker is None:
-            self.broker = mitogen.master.Broker()
+            self.broker = Broker()
 
         path = self._listener_for_name(inventory_name)
         if path != self.listener_path:

docs/changelog.rst

@@ -94,6 +94,11 @@ Mitogen for Ansible
   for Unicode file contents. Now the file may contain data in any single byte
   encoding.
 
+* `#602 <https://github.com/dw/mitogen/issues/602>`_: connection configuration
+  is more accurately inferred for `meta: reset_connection`, the `synchronize`
+  module, and for any other action plug-ins that establish new connections of
+  their own.
+
 * `7ae926b3 <https://github.com/dw/mitogen/commit/7ae926b3>`_: the
   ``lineinfile`` module began leaking writable temporary file descriptors since
   Ansible 2.7.0. When ``lineinfile`` was used to create or modify a script, and
@@ -157,6 +162,7 @@ Mitogen would not be possible without the support of users. A huge thanks for
 bug reports, testing, features and fixes in this release contributed by
 `Andreas Hubert <https://github.com/peshay>`_.
 `Anton Markelov <https://github.com/strangeman>`_,
+`Dave Cottlehuber <https://github.com/dch>`_,
 `Nigel Metheringham <https://github.com/nigelm>`_,
 `Orion Poplawski <https://github.com/opoplawski>`_,
 `Pieter Voet <https://github.com/pietervoet/>`_,