Support LXD; closes #339.

docs/ansible.rst

@@ -569,10 +569,10 @@ additional differences exist that may break existing playbooks.
 LXC
 ~~~
 
-Like `lxc <https://docs.ansible.com/ansible/2.6/plugins/connection/lxc.html>`_
-and `lxd <https://docs.ansible.com/ansible/2.6/plugins/connection/lxd.html>`_
-except connection delegation is supported, and ``lxc-attach`` is always used
-rather than the LXC Python bindings, as is usual with ``lxc``.
+Connect to classic LXC containers, like `lxc
+<https://docs.ansible.com/ansible/2.6/plugins/connection/lxc.html>`_ except
+connection delegation is supported, and ``lxc-attach`` is always used rather
+than the LXC Python bindings, as is usual with ``lxc``.
 
 The ``lxc-attach`` command must be available on the host machine.
 
@@ -580,6 +580,20 @@ The ``lxc-attach`` command must be available on the host machine.
 * ``ansible_host``: Name of LXC container (default: inventory hostname).
 
 
+.. _method-lxd:
+
+LXD
+~~~
+
+Connect to modern LXD containers, like `lxd
+<https://docs.ansible.com/ansible/2.6/plugins/connection/lxd.html>`_ except
+connection delegation is supported. The ``lxc`` command must be available on
+the host machine.
+
+* ``ansible_python_interpreter``
+* ``ansible_host``: Name of LXC container (default: inventory hostname).
+
+
 .. _machinectl:
 
 Machinectl
@@ -602,21 +616,23 @@ Setns
 ~~~~~
 
 The ``setns`` method connects to Linux containers via `setns(2)
-<https://linux.die.net/man/2/setns>`_. Unlike :ref:`method-docker` and
-:ref:`method-lxc` the namespace transition is handled internally, ensuring
-optimal throughput to the child. This is necessary for :ref:`machinectl` where
-only PTY channels are supported.
+<https://linux.die.net/man/2/setns>`_. Unlike :ref:`method-docker`,
+:ref:`method-lxc`, and :ref:`method-lxd` the namespace transition is handled
+internally, ensuring optimal throughput to the child. This is necessary for
+:ref:`machinectl` where only PTY channels are supported.
 
 A utility program must be installed to discover the PID of the container's root
 process.
 
-* ``mitogen_kind``: one of ``docker``, ``lxc`` or ``machinectl``.
+* ``mitogen_kind``: one of ``docker``, ``lxc``, ``lxd`` or ``machinectl``.
 * ``ansible_host``: Name of container as it is known to the corresponding tool
   (default: inventory hostname).
 * ``ansible_user``: Name of user within the container to execute as.
 * ``mitogen_docker_path``: path to Docker if not available on the system path.
-* ``mitogen_lxc_info_path``: path to ``lxc-info`` command if not available as
-  ``/usr/bin/lxc-info``.
+* ``mitogen_lxc_path``: path to LXD's ``lxc`` command if not available as
+  ``lxc-info``.
+* ``mitogen_lxc_info_path``: path to LXC classic's ``lxc-info`` command if not
+  available as ``lxc-info``.
 * ``mitogen_machinectl_path``: path to ``machinectl`` command if not available
   as ``/bin/machinectl``.
 

docs/api.rst

@@ -590,8 +590,8 @@ Router Class
 
     .. method:: lxc (container, lxc_attach_path=None, \**kwargs)
 
-        Construct a context on the local machine within an LXC container using
-        the ``lxc-attach`` program.
+        Construct a context on the local machine within an LXC classic
+        container using the ``lxc-attach`` program.
 
         Accepts all parameters accepted by :py:meth:`local`, in addition to:
 
@@ -602,6 +602,19 @@ Router Class
             will be searched if given as a filename. Defaults to
             ``lxc-attach``.
 
+    .. method:: lxc (container, lxc_attach_path=None, \**kwargs)
+
+        Construct a context on the local machine within a LXD container using
+        the ``lxc`` program.
+
+        Accepts all parameters accepted by :py:meth:`local`, in addition to:
+
+        :param str container:
+            Existing container to connect to. Defaults to ``None``.
+        :param str lxc_path:
+            Filename or complete path to the ``lxc`` binary. ``PATH`` will be
+            searched if given as a filename. Defaults to ``lxc``.
+
     .. method:: setns (container, kind, docker_path=None, lxc_info_path=None, machinectl_path=None, \**kwargs)
 
         Construct a context in the style of :meth:`local`, but change the
@@ -609,7 +622,8 @@ Router Class
         executing Python.
 
         The namespaces to use, and the active root file system are taken from
-        the root PID of a running Docker, LXC, or systemd-nspawn container.
+        the root PID of a running Docker, LXC, LXD, or systemd-nspawn
+        container.
 
         A program is required only to find the root PID, after which management
         of the child Python interpreter is handled directly.
@@ -617,14 +631,16 @@ Router Class
         :param str container:
             Container to connect to.
         :param str kind:
-            One of ``docker``, ``lxc`` or ``machinectl``.
+            One of ``docker``, ``lxc``, ``lxd`` or ``machinectl``.
         :param str docker_path:
             Filename or complete path to the Docker binary. ``PATH`` will be
             searched if given as a filename. Defaults to ``docker``.
+        :param str lxc_path:
+            Filename or complete path to the LXD ``lxc`` binary. ``PATH`` will
+            be searched if given as a filename. Defaults to ``lxc``.
         :param str lxc_info_path:
-            Filename or complete path to the ``lxc-info`` binary. ``PATH``
-            will be searched if given as a filename. Defaults to
-            ``lxc-info``.
+            Filename or complete path to the LXC ``lxc-info`` binary. ``PATH``
+            will be searched if given as a filename. Defaults to ``lxc-info``.
         :param str machinectl_path:
             Filename or complete path to the ``machinectl`` binary. ``PATH``
             will be searched if given as a filename. Defaults to

mitogen/core.py

@@ -614,6 +614,7 @@ class Importer(object):
             'fork',
             'jail',
             'lxc',
+            'lxd',
             'master',
             'minify',
             'parent',

mitogen/lxd.py

@@ -0,0 +1,70 @@
+# 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 logging
+
+import mitogen.core
+import mitogen.parent
+
+
+LOG = logging.getLogger(__name__)
+
+
+class Stream(mitogen.parent.Stream):
+    child_is_immediate_subprocess = False
+    create_child_args = {
+        # If lxc finds any of stdin, stdout, stderr connected to a TTY, to
+        # prevent input injection it creates a proxy pty, forcing all IO to be
+        # buffered in <4KiB chunks. So ensure stderr is also routed to the
+        # socketpair.
+        'merge_stdio': True
+    }
+
+    container = None
+    lxc_path = 'lxc'
+    python_path = 'python'
+
+    def construct(self, container, lxc_path=None, **kwargs):
+        super(Stream, self).construct(**kwargs)
+        self.container = container
+        if lxc_path:
+            self.lxc_path = lxc_path
+
+    def connect(self):
+        super(Stream, self).connect()
+        self.name = u'lxd.' + self.container
+
+    def get_boot_command(self):
+        bits = [
+            self.lxc_path,
+            'exec',
+            '--force-noninteractive',
+            self.container,
+            '--',
+        ]
+        return bits + super(Stream, self).get_boot_command()

mitogen/parent.py

@@ -1288,6 +1288,9 @@ class Router(mitogen.core.Router):
     def lxc(self, **kwargs):
         return self.connect(u'lxc', **kwargs)
 
+    def lxd(self, **kwargs):
+        return self.connect(u'lxd', **kwargs)
+
     def setns(self, **kwargs):
         return self.connect(u'setns', **kwargs)
 

mitogen/setns.py

@@ -94,6 +94,16 @@ def get_lxc_pid(path, name):
     raise Error("could not find PID from lxc-info output.\n%s", output)
 
 
+def get_lxd_pid(path, name):
+    output = _run_command([path, 'info', name])
+    for line in output.splitlines():
+        bits = line.split()
+        if bits and bits[0] == 'Pid:':
+            return int(bits[1])
+
+    raise Error("could not find PID from lxc output.\n%s", output)
+
+
 def get_machinectl_pid(path, name):
     output = _run_command([path, 'status', name])
     for line in output.splitlines():
@@ -110,18 +120,22 @@ class Stream(mitogen.parent.Stream):
     container = None
     username = None
     kind = None
+    python_path = 'python'
     docker_path = 'docker'
+    lxc_path = 'lxc'
     lxc_info_path = 'lxc-info'
     machinectl_path = 'machinectl'
 
     GET_LEADER_BY_KIND = {
         'docker': ('docker_path', get_docker_pid),
         'lxc': ('lxc_info_path', get_lxc_pid),
+        'lxd': ('lxc_path', get_lxd_pid),
         'machinectl': ('machinectl_path', get_machinectl_pid),
     }
 
     def construct(self, container, kind, username=None, docker_path=None,
-                  lxc_info_path=None, machinectl_path=None, **kwargs):
+                  lxc_path=None, lxc_info_path=None, machinectl_path=None,
+                  **kwargs):
         super(Stream, self).construct(**kwargs)
         if kind not in self.GET_LEADER_BY_KIND:
             raise Error('unsupported container kind: %r', kind)
@@ -132,6 +146,8 @@ class Stream(mitogen.parent.Stream):
             self.username = username
         if docker_path:
             self.docker_path = docker_path
+        if lxc_path:
+            self.lxc_path = lxc_path
         if lxc_info_path:
             self.lxc_info_path = lxc_info_path
         if machinectl_path: