suri-graphite: add daemonization capability

You can now use -d or --daemon to daemonize the process.

contrib/suri-graphite

@@ -1,5 +1,5 @@
 #!/usr/bin/env python
-# Copyright (C) 2013 Eric Leblond <eric@regit.org>
+# Copyright (C) 2013, 2015 Eric Leblond <eric@regit.org>
 #
 # You can copy, redistribute or modify this Program under the terms of
 # the GNU General Public License version 3 as published by the Free
@@ -20,6 +20,13 @@ import socket
 import time
 import argparse
 
+have_daemon = True
+try:
+    import daemon
+except:
+    logging.warning("No daemon support available, install python-daemon if feature is needed")
+    have_daemon = False
+
 parser = argparse.ArgumentParser(prog='suri-graphite', description='Export suricata stats to Graphite')
 parser.add_argument('-H', '--host', default='localhost', help='Host running Graphite')
 parser.add_argument('-P', '--port', default=2003, help='Port of Graphite data socket')
@@ -29,8 +36,14 @@ parser.add_argument('-r', '--root', default='suricata.perf', help='Prefix of dat
 parser.add_argument('socket', help='suricata socket file to connect to',
                     default="/usr/local/var/run/suricata/suricata-command.socket", nargs='?')
 parser.add_argument('-v', '--verbose', action='store_const', const=True, help='verbose output', default=False)
+if have_daemon:
+    parser.add_argument('-d', '--daemon', default=False, action="store_true", help="Run as unix daemon")
+
 
 args = parser.parse_args()
+
+
+def main_task(args):
     sc = suricatasc.SuricataSC(args.socket)
     sc.connect()
 
@@ -49,3 +62,9 @@ while 1:
         if args.oneshot:
             break
         time.sleep(float(args.delay))
+
+if have_daemon and args.daemon:
+    with daemon.DaemonContext():
+        main_task(args)
+else:
+    main_task(args)