issue #615: use FileService for target->controll file transfers

ansible_mitogen/connection.py

@@ -950,11 +950,12 @@ class Connection(ansible.plugins.connection.ConnectionBase):
         :param str out_path:
             Local filesystem path to write.
         """
-        output = self.get_chain().call(
-            ansible_mitogen.target.read_path,
-            mitogen.utils.cast(in_path),
+        self._connect()
+        ansible_mitogen.target.transfer_file(
+            context=self.context,
+            in_path=in_path,
+            out_path=out_path
         )
-        ansible_mitogen.target.write_path(out_path, output)
 
     def put_data(self, out_path, data, mode=None, utimes=None):
         """

mitogen/core.py

@@ -395,6 +395,12 @@ else:
         return _partition(s, sep, s.find) or (s, '', '')
 
 
+def _has_parent_authority(context_id):
+    return (
+        (context_id == mitogen.context_id) or
+        (context_id in mitogen.parent_ids)
+    )
+
 def has_parent_authority(msg, _stream=None):
     """
     Policy function for use with :class:`Receiver` and
@@ -403,8 +409,7 @@ def has_parent_authority(msg, _stream=None):
     <Stream.auth_id>` has been set to that of a parent context or the current
     context.
     """
-    return (msg.auth_id == mitogen.context_id or
-            msg.auth_id in mitogen.parent_ids)
+    return _has_parent_authority(msg.auth_id)
 
 
 def _signals(obj, signal):

mitogen/service.py

@@ -1023,7 +1023,11 @@ class FileService(Service):
         :raises Error:
             Unregistered path, or Sender did not match requestee context.
         """
-        if path not in self._paths and not self._prefix_is_authorized(path):
+        if (
+            (path not in self._paths) and
+            (not self._prefix_is_authorized(path)) and
+            (not mitogen.core._has_parent_authority(msg.auth_id))
+        ):
             msg.reply(mitogen.core.CallError(
                 Error(self.unregistered_msg % (path,))
             ))

tests/ansible/tests/connection_test.py

@@ -99,6 +99,21 @@ class OptionalIntTest(testlib.TestCase):
         self.assertEquals(None, self.func({1:2}))
 
 
+class FetchFileTest(ConnectionMixin, testlib.TestCase):
+    def test_success(self):
+        with tempfile.NamedTemporaryFile(prefix='mitotest') as ifp, \
+            tempfile.NamedTemporaryFile(prefix='mitotest') as ofp:
+            ifp.write('x' * (1048576 * 4))
+            ifp.flush()
+            ifp.seek(0)
+
+            self.conn.fetch_file(ifp.name, ofp.name)
+            # transfer_file() uses os.rename rather than direct data overwrite,
+            # so we must reopen.
+            with open(ofp.name, 'rb') as fp:
+                self.assertEquals(ifp.read(), fp.read())
+
+
 class PutDataTest(ConnectionMixin, testlib.TestCase):
     def test_out_path(self):
         path = tempfile.mktemp(prefix='mitotest')