initial commit

hosts.py

@@ -0,0 +1,59 @@
+#!/usr/bin/env python
+
+import argparse
+import json
+import sys
+
+
+def get_hosts(hosts_file='/etc/hosts'):
+    '''
+    Get the hostsnames from /etc/hosts.
+    Returns: A set of hostnames.
+    '''
+    rv = []
+    with open(hosts_file, 'r') as f:
+        for line in f:
+            if line == '\n':
+                continue
+            if line[0] == '#':
+                continue
+            rv.append(line.split()[1])
+    rv = set(rv)
+    ignore = {'localhost', 'ip6-allnodes', 'ip6-allrouters'}
+    return rv.difference(ignore)
+
+
+def get_args(args_list):
+    """
+    Parse the arguments and make sure only
+    that --list or --host is given, not both.
+    """
+    parser = argparse.ArgumentParser(
+        description='ansible inventory script parsing /etc/hosts')
+    mutex_group = parser.add_mutually_exclusive_group(required=True)
+    help_list = 'list all hosts from /etc/hosts'
+    mutex_group.add_argument('--list', action='store_true', help=help_list)
+    help_host = 'display variables for a host'
+    mutex_group.add_argument('--host', help=help_host)
+    return parser.parse_args(args_list)
+
+
+def main(args_list):
+    """
+    Print a json list of the hosts if --list is given.
+    Does not support host vars.
+    Print an empty dictionary if --host is passed to remain valid.
+    """
+    args = get_args(args_list)
+    if args.list:
+        print(json.dumps({
+            'all': {
+                'hosts': list(get_hosts()),
+            }
+        }))
+    if args.host:
+        print(json.dumps({}))
+
+
+if __name__ == '__main__':
+    main(sys.argv[1:])