Added cobbler external inventory script, which is a demo of how external inventory

works in Ansible in general.

examples/scripts/cobbler_external_inventory.py

+#!/usr/bin/python
+
+"""
+Cobbler external inventory script
+=================================
+
+Ansible has a feature where instead of reading from /etc/ansible/hosts
+as a text file, it can query external programs to obtain the list
+of hosts, groups the hosts are in, and even variables to assign to each host.  
+
+To use this, copy this file over /etc/ansible/hosts and chmod +x the file.
+This, more or less, allows you to keep one central database containing
+info about all of your managed instances.
+
+This script is an example of sourcing that data from Cobbler
+(http://cobbler.github.com).  With cobbler each --mgmt-class in cobbler 
+will correspond to a group in Ansible, and --ks-meta variables will be 
+passed down for use in templates or even in argument lines.
+
+NOTE: The cobbler system names will not be used.  Make sure a
+cobbler --dns-name is set for each cobbler system.   If a system
+appears with two DNS names we do not add it twice because we don't want
+ansible talking to it twice.  The first one found will be used. If no
+--dns-name is set the system will NOT be visible to ansible.  We do
+not add cobbler system names because there is no requirement in cobbler
+that those correspond to addresses.  
+
+See http://ansible.github.com/api.html for more info
+
+Tested with Cobbler 2.0.11. 
+"""
+
+# (c) 2012, Michael DeHaan <michael.dehaan@gmail.com>
+#
+# 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 sys
+import xmlrpclib
+import shlex
+
+try:
+    import json
+except:
+    import simplejson as json
+
+conn = xmlrpclib.Server("http://127.0.0.1/cobbler_api", allow_none=True)
+
+###################################################
+# executed with no parameters, return the list of
+# all groups and hosts
+
+if len(sys.argv) == 1:
+
+    systems = conn.get_item_names('system')
+    groups = { 'ungrouped' : [] }
+
+    for system in systems:
+
+        data = conn.get_blended_data(None, system)
+
+        dns_name = None
+        interfaces = data['interfaces']
+        for (iname, ivalue) in interfaces.iteritems():
+            this_dns_name = ivalue.get('dns_name', None)
+            if this_dns_name is not None:
+                dns_name = this_dns_name       
+ 
+        if dns_name is None:
+            continue
+
+        classes  = data['mgmt_classes']
+        for cls in classes:
+            if cls not in groups:
+                groups[cls] = []
+            # hostname is not really what we want to insert, really insert the
+            # first DNS name but no further DNS names
+            groups[cls].append(dns_name)
+ 
+    print json.dumps(groups)
+    sys.exit(0)
+
+#####################################################
+# executed with a hostname as a parameter, return the
+# variables for that host
+
+if len(sys.argv) == 2:
+
+    # look up the system record for the given DNS name
+    result = conn.find_system_by_dns_name(sys.argv[1])
+    system = result.get('name', None)
+    data = {}
+    if system is None:
+        print json.dumps({})
+        sys.exit(1)
+    data = conn.get_system_for_koan(system)
+
+    # return the ksmeta data for that system
+    metadata = data['ks_meta']
+    tokens = shlex.split(metadata)
+    results = {}
+    for t in tokens:
+        if t.find("=") != -1:
+           (k,v) = t.split("=",1)
+           results[k]=v
+    print json.dumps(results)
+    sys.exit(0)
+