setns: support changing user.

To match existing third party plugin.

ansible_mitogen/connection.py

@@ -112,6 +112,26 @@ def _connect_lxc(spec):
     }
 
 
+def _connect_machinectl(spec):
+    return _connect_setns(dict(spec, mitogen_kind='machinectl'))
+
+
+def _connect_setns(spec):
+    print 'ULTRAFLEEN', spec['remote_addr'], spec['remote_user']
+    return {
+        'method': 'setns',
+        'kwargs': {
+            'container': spec['remote_addr'],
+            'username': spec['remote_user'],
+            'python_path': spec['python_path'],
+            'kind': spec['mitogen_kind'],
+            'docker_path': spec['mitogen_docker_path'],
+            'lxc_info_path': spec['mitogen_lxc_info_path'],
+            'machinectl_path': spec['mitogen_machinectl_path'],
+        }
+    }
+
+
 def _connect_sudo(spec):
     return {
         'method': 'sudo',
@@ -132,6 +152,8 @@ CONNECTION_METHOD = {
     'local': _connect_local,
     'lxc': _connect_lxc,
     'lxd': _connect_lxc,
+    'machinectl': _connect_machinectl,
+    'setns': _connect_setns,
     'ssh': _connect_ssh,
     'sudo': _connect_sudo,
 }
@@ -178,6 +200,10 @@ def config_from_play_context(transport, inventory_name, connection):
             for term in shlex.split(s or '')
         ],
         'mitogen_via': connection.mitogen_via,
+        'mitogen_kind': connection.mitogen_kind,
+        'mitogen_docker_path': connection.mitogen_docker_path,
+        'mitogen_lxc_info_path': connection.mitogen_lxc_info_path,
+        'mitogen_machinectl_path': connection.mitogen_machinectl_path,
     }
 
 
@@ -202,6 +228,10 @@ def config_from_hostvars(transport, inventory_name, connection,
         'private_key_file': (hostvars.get('ansible_ssh_private_key_file') or
                              hostvars.get('ansible_private_key_file')),
         'mitogen_via': hostvars.get('mitogen_via'),
+        'mitogen_kind': hostvars.get('mitogen_kind'),
+        'mitogen_docker_path': hostvars.get('mitogen_docker_path'),
+        'mitogen_lxc_info_path': hostvars.get('mitogen_lxc_info_path'),
+        'mitogen_machinectl_path': hostvars.get('mitogen_machinctl_path'),
     })
 
 
@@ -232,6 +262,18 @@ class Connection(ansible.plugins.connection.ConnectionBase):
     #: Set to 'mitogen_via' by on_action_run().
     mitogen_via = None
 
+    #: Set to 'mitogen_kind' by on_action_run().
+    mitogen_kind = None
+
+    #: Set to 'mitogen_docker_path' by on_action_run().
+    mitogen_docker_path = None
+
+    #: Set to 'mitogen_lxc_info_path' by on_action_run().
+    mitogen_lxc_info_path = None
+
+    #: Set to 'mitogen_lxc_info_path' by on_action_run().
+    mitogen_machinectl_path = None
+
     #: Set to 'inventory_hostname' by on_action_run().
     inventory_hostname = None
 
@@ -267,6 +309,10 @@ class Connection(ansible.plugins.connection.ConnectionBase):
         self.python_path = task_vars.get('ansible_python_interpreter',
                                          '/usr/bin/python')
         self.mitogen_via = task_vars.get('mitogen_via')
+        self.mitogen_kind = task_vars.get('mitogen_kind')
+        self.mitogen_docker_path = task_vars.get('mitogen_docker_path')
+        self.mitogen_lxc_info_path = task_vars.get('mitogen_lxc_info_path')
+        self.mitogen_machinectl_path = task_vars.get('mitogen_machinectl_path')
         self.inventory_hostname = task_vars['inventory_hostname']
         self.host_vars = task_vars['hostvars']
         self.close(new_task=True)

ansible_mitogen/strategy.py

@@ -63,12 +63,11 @@ def wrap_action_loader__get(name, *args, **kwargs):
 
 def wrap_connection_loader__get(name, play_context, new_stdin, **kwargs):
     """
-    While the mitogen strategy is active, rewrite connection_loader.get() calls
-    for the 'ssh' and 'local' transports into corresponding requests for the
-    'mitogen' connection type, passing the original transport name into it as
-    an argument, so that it can emulate the original type.
+    While the strategy is active, rewrite connection_loader.get() calls for
+    some transports into requests for a compatible Mitogen transport.
     """
-    if name in ('ssh', 'local', 'docker', 'lxc', 'lxd', 'jail'):
+    if name in ('docker', 'jail', 'local', 'lxc',
+                'lxd', 'machinectl', 'setns', 'ssh'):
         name = 'mitogen_' + name
     return connection_loader__get(name, play_context, new_stdin, **kwargs)
 

ansible_mitogen/target.py

@@ -159,7 +159,7 @@ def transfer_file(context, in_path, out_path, sync=False, set_owner=False):
                                     prefix='.ansible_mitogen_transfer-',
                                     dir=os.path.dirname(out_path))
     fp = os.fdopen(fd, 'wb', mitogen.core.CHUNK_SIZE)
-    LOG.debug('transfer_file(%r) tempory file: %s', out_path, tmp_path)
+    LOG.debug('transfer_file(%r) temporary file: %s', out_path, tmp_path)
 
     try:
         try:

docs/ansible.rst

@@ -455,6 +455,20 @@ connection delegation is supported.
 * ``ansible_user``: Name of user within the container to execute as.
 
 
+Machinectl
+~~~~~~~~~~
+
+Behaves like `machinectl
+<https://github.com/BaxterStockman/ansible-connection-machinectl>`_ except
+connection delegation is supported. This is a lightweight wrapper around the
+``setns`` method below.
+
+* ``ansible_host``: Name of Docker container (default: inventory hostname).
+* ``ansible_user``: Name of user within the container to execute as.
+* ``mitogen_machinectl_path``: path to ``machinectl`` command if not available
+  as ``/bin/machinectl``.
+
+
 Sudo
 ~~~~
 
@@ -478,9 +492,10 @@ supported.
 Utility programs must still be installed to discover the PID of the container's
 root process.
 
-* ``mitogen_container_kind``: one of ``docker``, ``lxc`` or ``machinectl``.
+* ``mitogen_kind``: one of ``docker``, ``lxc`` 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``.
@@ -537,6 +552,7 @@ rather than the LXC Python bindings, as is usual with the ``lxc`` method.
 
 The ``lxc-attach`` command must be available on the host machine.
 
+* ``ansible_python_interpreter``
 * ``ansible_host``: Name of LXC container (default: inventory hostname).
 
 

mitogen/parent.py

@@ -484,9 +484,9 @@ def _proxy_connect(name, method_name, kwargs, econtext):
         return {
             'id': None,
             'name': None,
-            'msg': '%s (error occurred on host %s)' % (
-                sys.exc_info()[1],
+            'msg': 'error occurred on host %s: %s' % (
                 socket.gethostname(),
+                sys.exc_info()[1],
             ),
         }
 

mitogen/setns.py

@@ -27,9 +27,12 @@
 # POSSIBILITY OF SUCH DAMAGE.
 
 import ctypes
+import grp
 import logging
 import os
+import pwd
 import subprocess
+import sys
 
 import mitogen.core
 import mitogen.parent
@@ -53,11 +56,16 @@ def setns(kind, fd):
 
 
 def _run_command(args):
+    argv = mitogen.parent.Argv(args)
+    try:
         proc = subprocess.Popen(
             args=args,
             stdout=subprocess.PIPE,
             stderr=subprocess.STDOUT
         )
+    except OSError:
+        e = sys.exc_info()[1]
+        raise Error('could not execute %s: %s', argv, e)
 
     output, _ = proc.communicate()
     if not proc.returncode:
@@ -97,6 +105,7 @@ def get_machinectl_pid(path, name):
 
 class Stream(mitogen.parent.Stream):
     container = None
+    username = None
     kind = None
     docker_path = 'docker'
     lxc_info_path = 'lxc-info'
@@ -108,7 +117,7 @@ class Stream(mitogen.parent.Stream):
         'machinectl': ('machinectl_path', get_machinectl_pid),
     }
 
-    def construct(self, container, kind, docker_path=None,
+    def construct(self, container, kind, username=None, docker_path=None,
                   lxc_info_path=None, machinectl_path=None, **kwargs):
         super(Stream, self).construct(**kwargs)
         if kind not in self.GET_LEADER_BY_KIND:
@@ -116,6 +125,8 @@ class Stream(mitogen.parent.Stream):
 
         self.container = container
         self.kind = kind
+        if username:
+            self.username = username
         if docker_path:
             self.docker_path = docker_path
         if lxc_info_path:
@@ -140,12 +151,43 @@ class Stream(mitogen.parent.Stream):
         except Exception, e:
             raise Error(str(e))
 
-        os.chroot('/proc/%s/root' % (self.leader_pid,))
+        os.chdir('/proc/%s/root' % (self.leader_pid,))
+        os.chroot('.')
         os.chdir('/')
         for fp in ns_fps:
             setns(fp.name, fp.fileno())
             fp.close()
 
+        for sym in 'endpwent', 'endgrent', 'endspent', 'endsgent':
+            try:
+                getattr(LIBC, sym)()
+            except AttributeError:
+                pass
+
+        if self.username:
+            try:
+                os.setgroups([grent.gr_gid
+                              for grent in grp.getgrall()
+                              if self.username in grent.gr_mem])
+                pwent = pwd.getpwnam(self.username)
+                os.setreuid(pwent.pw_uid, pwent.pw_uid)
+                # shadow-4.4/libmisc/setupenv.c. Not done: MAIL, PATH
+                os.environ.update({
+                    'HOME': pwent.pw_dir,
+                    'SHELL': pwent.pw_shell or '/bin/sh',
+                    'LOGNAME': self.username,
+                    'USER': self.username,
+                })
+                if ((os.path.exists(pwent.pw_dir) and
+                     os.access(pwent.pw_dir, os.X_OK))):
+                    os.chdir(pwent.pw_dir)
+            except Exception:
+                e = sys.exc_info()[1]
+                raise Error(self.username_msg, self.username, self.container,
+                            type(e).__name__, e)
+
+    username_msg = 'while transitioning to user %r in container %r: %s: %s'
+
     def get_boot_command(self):
         # With setns(CLONE_NEWPID), new children of the caller receive a new
         # PID namespace, however the caller's namespace won't change. That

tests/parent_test.py

@@ -68,7 +68,7 @@ class StreamErrorTest(testlib.RouterMixin, testlib.TestCase):
                 connect_timeout=3,
             )
         )
-        self.assertEquals(e.args[0], "EOF on stream; last 300 bytes received: ''")
+        self.assertTrue("EOF on stream; last 300 bytes received: ''" in e.args[0])
 
     def test_direct_enoent(self):
         e = self.assertRaises(mitogen.core.StreamError,
@@ -89,8 +89,8 @@ class StreamErrorTest(testlib.RouterMixin, testlib.TestCase):
                 connect_timeout=3,
             )
         )
-        prefix = 'Child start failed: [Errno 2] No such file or directory.'
-        self.assertTrue(e.args[0].startswith(prefix))
+        s = 'Child start failed: [Errno 2] No such file or directory.'
+        self.assertTrue(s in e.args[0])
 
 
 class ContextTest(testlib.RouterMixin, unittest2.TestCase):