Merge pull request #13433 from fghaas/lxc

Add inventory script for LXC containers

contrib/inventory/lxc_inventory.py

@@ -0,0 +1,67 @@
+#!/usr/bin/env python
+#
+# (c) 2015-16 Florian Haas, hastexo Professional Services GmbH
+# <florian@hastexo.com>
+# Based in part on:
+# libvirt_lxc.py, (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/>.
+"""
+Ansible inventory script for LXC containers. Requires Python
+bindings for LXC API.
+
+In LXC, containers can be grouped by setting the lxc.group option,
+which may be found more than once in a container's
+configuration. So, we enumerate all containers, fetch their list
+of groups, and then build the dictionary in the way Ansible expects
+it.
+"""
+from __future__ import print_function
+
+import sys
+import lxc
+import json
+
+def build_dict():
+    """Returns a dictionary keyed to the defined LXC groups. All
+    containers, including the ones not in any group, are included in the
+    "all" group."""
+    # Enumerate all containers, and list the groups they are in. Also,
+    # implicitly add every container to the 'all' group.
+    containers = dict([(c,
+                        ['all'] +
+                        (lxc.Container(c).get_config_item('lxc.group') or []))
+                       for c in lxc.list_containers()])
+
+    # Extract the groups, flatten the list, and remove duplicates
+    groups = set(sum([g for g in containers.values()], []))
+
+    # Create a dictionary for each group (including the 'all' group
+    return dict([(g, {'hosts': [k for k, v in containers.items() if g in v],
+                      'vars': {'ansible_connection':'lxc'}}) for g in groups])
+
+def main(argv):
+    """Returns a JSON dictionary as expected by Ansible"""
+    result = build_dict()
+    if len(argv) == 2 and argv[1] == '--list':
+        json.dump(result, sys.stdout)
+    elif len(argv) == 3 and argv[1] == '--host':
+        json.dump({'ansible_connection': 'lxc'}, sys.stdout)
+    else:
+        print("Need an argument, either --list or --host <host>", file=sys.stderr)
+
+if __name__ == '__main__':
+    main(sys.argv)