Add a plugin that permit to use ansible for lxc system, using libvirt

Using -c lxc and the domain name as hostname, this permit to manage a whole
range of container, provided they are managed and created by libvirtd.

lib/ansible/runner/connection_plugins/lxc.py

+# Based on local.py (c) 2012, Michael DeHaan <michael.dehaan@gmail.com>
+# Based on chroot.py (c) 2013, Maykel Moya <mmoya@speedyrails.com>
+# (c) 2013, Michael Scherer <misc@zarb.org>
+#
+# This file is part of Ansible
+#
+# Ansible is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Ansible is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
+
+import distutils.spawn
+import os
+import subprocess
+from ansible import errors
+from ansible.callbacks import vvv
+
+class Connection(object):
+    ''' Local lxc based connections '''
+
+    def _search_executable(self, executable):
+        cmd = distutils.spawn.find_executable(executable)
+        if not cmd:
+            raise errors.AnsibleError("%s command not found in PATH") % executable
+        return cmd
+
+    def _check_domain(self, domain):
+        p = subprocess.Popen([self.cmd, '-q', '-c', 'lxc:///', 'dominfo', domain],
+                             stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+        p.communicate()
+        if p.returncode:
+            raise errors.AnsibleError("%s is not a lxc defined in libvirt" % domain)
+
+    def __init__(self, runner, host, port, *args, **kwargs):
+        self.lxc = host
+
+        self.cmd = self._search_executable('virsh')
+
+        self._check_domain(host)
+
+        self.runner = runner
+        self.host = host
+        # port is unused, since this is local
+        self.port = port
+
+    def connect(self, port=None):
+        ''' connect to the lxc; nothing to do here '''
+
+        vvv("THIS IS A LOCAL LXC DIR", host=self.lxc)
+
+        return self
+
+    def _generate_cmd(self, executable, cmd):
+        if executable:
+            local_cmd = [self.cmd, '-q', '-c', 'lxc:///', 'lxc-enter-namespace', self.lxc, '--', executable , '-c', cmd]
+        else:
+            local_cmd = '%s -q -c lxc:/// lxc-enter-namespace %s -- %s' % (self.cmd, self.lxc, cmd)
+        return local_cmd
+
+    def exec_command(self, cmd, tmp_path, sudo_user, sudoable=False, executable='/bin/sh'):
+        ''' run a command on the chroot '''
+
+        # We enter lxc as root so sudo stuff can be ignored
+        local_cmd = self._generate_cmd(executable, cmd)
+
+        vvv("EXEC %s" % (local_cmd), host=self.lxc)
+        p = subprocess.Popen(local_cmd, shell=isinstance(local_cmd, basestring),
+                             cwd=self.runner.basedir,
+                             stdin=subprocess.PIPE,
+                             stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+
+        stdout, stderr = p.communicate()
+        return (p.returncode, '', stdout, stderr)
+
+    def _normalize_path(self, path, prefix):
+        if not path.startswith(os.path.sep):
+            path = os.path.join(os.path.sep, path)
+        normpath = os.path.normpath(path)
+        return os.path.join(prefix, normpath[1:])
+
+    def put_file(self, in_path, out_path):
+        ''' transfer a file from local to lxc '''
+
+        out_path = self._normalize_path(out_path, '/')
+        vvv("PUT %s TO %s" % (in_path, out_path), host=self.lxc)
+        
+        local_cmd = [self.cmd, '-q', '-c', 'lxc:///', 'lxc-enter-namespace', self.lxc, '--', '/bin/tee', out_path]
+        vvv("EXEC %s" % (local_cmd), host=self.lxc)
+
+        p = subprocess.Popen(local_cmd, cwd=self.runner.basedir,
+                             stdin=subprocess.PIPE,
+                             stdout=subprocess.PIPE, stderr=subprocess.PIPE) 
+        stdout, stderr = p.communicate(open(in_path,'rb').read())
+ 
+    def fetch_file(self, in_path, out_path):
+        ''' fetch a file from lxc to local '''
+
+        in_path = self._normalize_path(in_path, '/')
+        vvv("FETCH %s TO %s" % (in_path, out_path), host=self.lxc)
+
+        local_cmd = [self.cmd, '-q', '-c', 'lxc:///', 'lxc-enter-namespace', self.lxc, '--', '/bin/cat', in_path]
+        vvv("EXEC %s" % (local_cmd), host=self.lxc)
+
+        p = subprocess.Popen(local_cmd, cwd=self.runner.basedir,
+                             stdin=subprocess.PIPE,
+                             stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+        stdout, stderr = p.communicate()
+        open(out_path,'wb').write(stdout)
+
+
+    def close(self):
+        ''' terminate the connection; nothing to do here '''
+        pass