ansible: add mitogen_ssh_compression variable.

ansible_mitogen/connection.py

@@ -70,6 +70,15 @@ def optional_int(value):
         return None
 
 
+def default(value, default):
+    """
+    Return `default` is `value` is :data:`None`, otherwise return `value`.
+    """
+    if value is None:
+        return default
+    return value
+
+
 def _connect_local(spec):
     """
     Return ContextService arguments for a local connection.
@@ -103,6 +112,7 @@ def _connect_ssh(spec):
             'check_host_keys': check_host_keys,
             'hostname': spec.remote_addr(),
             'username': spec.remote_user(),
+            'compression': default(spec.mitogen_ssh_compression(), True),
             'password': spec.password(),
             'port': spec.port(),
             'python_path': spec.python_path(),

ansible_mitogen/transport_config.py

@@ -273,6 +273,12 @@ class Spec(with_metaclass(abc.ABCMeta, object)):
         The SSH debug level.
         """
 
+    @abc.abstractmethod
+    def mitogen_ssh_compression(self):
+        """
+        Whether SSH compression is enabled.
+        """
+
     @abc.abstractmethod
     def extra_args(self):
         """
@@ -398,6 +404,9 @@ class PlayContextSpec(Spec):
     def mitogen_ssh_debug_level(self):
         return self._connection.get_task_var('mitogen_ssh_debug_level')
 
+    def mitogen_ssh_compression(self):
+        return self._connection.get_task_var('mitogen_ssh_compression')
+
     def extra_args(self):
         return self._connection.get_extra_args()
 
@@ -577,5 +586,8 @@ class MitogenViaSpec(Spec):
     def mitogen_ssh_debug_level(self):
         return self._host_vars.get('mitogen_ssh_debug_level')
 
+    def mitogen_ssh_compression(self):
+        return self._host_vars.get('mitogen_ssh_compression')
+
     def extra_args(self):
         return []  # TODO

docs/ansible.rst

@@ -901,6 +901,10 @@ except connection delegation is supported.
 * ``ssh_args``, ``ssh_common_args``, ``ssh_extra_args``
 * ``mitogen_ssh_debug_level``: integer between `0..3` indicating the SSH client
   debug level. Ansible must also be run with '-vvv' to view the output.
+* ``mitogen_ssh_compression``: :data:`True` to enable SSH compression,
+  otherwise :data:`False`. This will change to off by default in a future
+  release. If you are targetting many hosts on a fast network, please consider
+  disabling SSH compression.
 
 
 Debugging