Add parameter to specify working directory

Fixes #24

daemonize.py

@@ -36,8 +36,12 @@ class Daemonize(object):
     :param verbose: send debug messages to logger if provided.
     :param logger: use this logger object instead of creating new one, if provided.
     :param foreground: stay in foreground; do not fork (for debugging)
+    :param chdir: change working directory if provided or /
     """
-    def __init__(self, app, pid, action, keep_fds=None, auto_close_fds=True, privileged_action=None, user=None, group=None, verbose=False, logger=None, foreground=False):
+    def __init__(self, app, pid, action,
+                 keep_fds=None, auto_close_fds=True, privileged_action=None,
+                 user=None, group=None, verbose=False, logger=None,
+                 foreground=False, chdir="/"):
         self.app = app
         self.pid = pid
         self.action = action
@@ -49,6 +53,7 @@ class Daemonize(object):
         self.verbose = verbose
         self.auto_close_fds = auto_close_fds
         self.foreground = foreground
+        self.chdir=chdir
 
     def sigterm(self, signum, frame):
         """
@@ -171,7 +176,7 @@ class Daemonize(object):
 
         # Change to a known directory. If this isn't done, starting a daemon in a subdirectory that
         # needs to be deleted results in "directory busy" errors.
-        os.chdir("/")
+        os.chdir(self.chdir)
 
         # Execute privileged action
         privileged_action_result = self.privileged_action()

tests/daemon_chdir.py

@@ -0,0 +1,18 @@
+#!/usr/bin/env python
+
+from sys import argv
+
+from daemonize import Daemonize
+
+pid = argv[1]
+working_dir = argv[2]
+file_name = argv[3]
+
+
+def main():
+    with open(file_name, "w") as f:
+        f.write("test")
+
+
+daemon = Daemonize(app="test_app", pid=pid, action=main, chdir=working_dir)
+daemon.start()

tests/test.py

@@ -6,6 +6,7 @@ import subprocess
 
 from tempfile import mkstemp
 from time import sleep
+from os.path import split
 
 NOBODY_UID = pwd.getpwnam("nobody").pw_uid
 if os.path.exists("/etc/debian_version"):
@@ -131,5 +132,23 @@ Stopping daemon.
         with open(self.logfile, "r") as contents:
             self.assertEqual(contents.read(), self.correct_log)
 
+
+class KeepFDsTest(unittest.TestCase):
+    def setUp(self):
+        self.pidfile = mkstemp()[1]
+        self.target = mkstemp()[1]
+        base, file = split(self.target)
+
+        os.system("python tests/daemon_chdir.py %s %s %s" % (self.pidfile, base, file))
+        sleep(1)
+
+    def tearDown(self):
+        os.system("kill `cat %s`" % self.pidfile)
+        sleep(.1)
+
+    def test_keep_fds(self):
+        log = open(self.target, "r").read()
+        self.assertEqual(log, "test")
+
 if __name__ == '__main__':
     unittest.main()