ansible: implement LXC support.

ansible_mitogen/connection.py

@@ -88,6 +88,17 @@ def _connect_docker(spec):
     }
 
 
+def _connect_lxc(spec):
+    return {
+        'method': 'lxc',
+        'kwargs': {
+            'container': spec['remote_addr'],
+            'python_path': spec['python_path'],
+            'connect_timeout': spec['ansible_ssh_timeout'] or spec['timeout'],
+        }
+    }
+
+
 def _connect_sudo(spec):
     return {
         'method': 'sudo',
@@ -103,10 +114,11 @@ def _connect_sudo(spec):
 
 
 CONNECTION_METHOD = {
-    'sudo': _connect_sudo,
-    'ssh': _connect_ssh,
-    'local': _connect_local,
     'docker': _connect_docker,
+    'local': _connect_local,
+    'lxc': _connect_lxc,
+    'ssh': _connect_ssh,
+    'sudo': _connect_sudo,
 }
 
 
@@ -494,3 +506,7 @@ class LocalConnection(Connection):
 
 class DockerConnection(Connection):
     transport = 'docker'
+
+
+class LxcConnection(Connection):
+    transport = 'lxc'

ansible_mitogen/plugins/connection/mitogen_lxc.py

@@ -0,0 +1,56 @@
+# Copyright 2017, David Wilson
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# 1. Redistributions of source code must retain the above copyright notice,
+# this list of conditions and the following disclaimer.
+#
+# 2. Redistributions in binary form must reproduce the above copyright notice,
+# this list of conditions and the following disclaimer in the documentation
+# and/or other materials provided with the distribution.
+#
+# 3. Neither the name of the copyright holder nor the names of its contributors
+# may be used to endorse or promote products derived from this software without
+# specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+
+import os.path
+import sys
+
+#
+# This is not the real Connection implementation module, it simply exists as a
+# proxy to the real module, which is loaded using Python's regular import
+# mechanism, to prevent Ansible's PluginLoader from making up a fake name that
+# results in ansible_mitogen plugin modules being loaded twice: once by
+# PluginLoader with a name like "ansible.plugins.connection.mitogen", which is
+# stuffed into sys.modules even though attempting to import it will trigger an
+# ImportError, and once under its canonical name, "ansible_mitogen.connection".
+#
+# Therefore we have a proxy module that imports it under the real name, and
+# sets up the duff PluginLoader-imported module to just contain objects from
+# the real module, so duplicate types don't exist in memory, and things like
+# debuggers and isinstance() work predictably.
+#
+
+try:
+    import ansible_mitogen
+except ImportError:
+    base_dir = os.path.dirname(__file__)
+    sys.path.insert(0, os.path.abspath(os.path.join(base_dir, '../../..')))
+    del base_dir
+
+from ansible_mitogen.connection import LxcConnection as Connection
+del os
+del sys

ansible_mitogen/strategy.py

@@ -68,7 +68,7 @@ def wrap_connection_loader__get(name, play_context, new_stdin, **kwargs):
     'mitogen' connection type, passing the original transport name into it as
     an argument, so that it can emulate the original type.
     """
-    if name in ('ssh', 'local', 'docker'):
+    if name in ('ssh', 'local', 'docker', 'lxc'):
         name = 'mitogen_' + name
     return connection_loader__get(name, play_context, new_stdin, **kwargs)
 

docs/ansible.rst

@@ -116,8 +116,8 @@ Noteworthy Differences
 * The ``sudo`` become method is available and ``su`` is planned. File bugs to
   register interest in additional methods.
 
-* The ``ssh``, ``local`` and ``docker`` connection types are available, with
+* The ``docker``, ``local``, ``lxc`` and ``ssh`` connection types are
-  more planned. File bugs to register interest.
+  available, with more planned. File bugs to register interest.
 
 * Local commands execute in a reuseable interpreter created identically to
   interpreters on targets. Presently one interpreter per ``become_user``
@@ -167,7 +167,7 @@ Connection Delegation
 
 Included is a preview of **Connection Delegation**, a Mitogen-specific
 implementation of `stackable connection plug-ins`_. This enables multi-hop
-connections via a bastion, or Docker connections delegated via their host
+connections via a bastion, or Docker/LCX connections delegated via their host
 machine, where reaching the host may itself entail recursive delegation.
 
 .. _Stackable connection plug-ins: https://github.com/ansible/proposals/issues/25
@@ -473,6 +473,15 @@ Docker support is fairly new, expect increased surprises for now.
 * ``ansible_user``: Name of user within the container to execute as.
 
 
+LXC
+~~~
+
+LXC support is fairly new, expect increased surprises for now. The
+``lxc-attach`` command is required to be available on the host machine.
+
+* ``ansible_host``: Name of LXC container.
+
+
 Debugging
 ---------