Implement and test PidFile option. Update TODO

dkimpy_milter/__init__.py

@@ -37,6 +37,7 @@ from Milter.utils import iniplist,parse_addr,parseaddr
 import dkimpy_milter.config as config
 from dkimpy_milter.util import drop_privileges
 from dkimpy_milter.util import setExceptHook
+from dkimpy_milter.util import write_pid
 
 FWS = re.compile(r'\r?\n[ \t]+')
   
@@ -235,6 +236,7 @@ def main():
     if milterconfig.get('Syslog'):
         syslog.openlog(os.path.basename(sys.argv[0]), syslog.LOG_PID, syslog.LOG_MAIL)
         setExceptHook()
+    write_pid(milterconfig)
     drop_privileges(milterconfig)
     Milter.factory = dkimMilter(milterconfig)
     Milter.set_flags(Milter.CHGHDRS + Milter.ADDHDRS)

dkimpy_milter/util.py

@@ -72,3 +72,23 @@ class ExceptHook:
 def setExceptHook():
     import sys
     sys.excepthook = ExceptHook(useSyslog = 1, useStderr = 1)
+
+####################
+def write_pid(milterconfig):
+    """Write PID in pidfile.  Will not overwrite an existing file."""
+    import os
+    import syslog
+    if not os.path.isfile(milterconfig.get('PidFile')):
+        pid = str(os.getpid())
+        try:
+            f = open(milterconfig.get('PidFile'), 'w')
+        except IOError as e:
+            if milterconfig.get('Syslog'):
+                syslog.syslog('Unable to write pidfle {0}.  IOError: {1}'.format(milterconfig.get('PidFile'), e))
+            raise
+        f.write(pid)
+        f.close()
+    else:
+        if milterconfig.get('Syslog'):
+            syslog.syslog('Unable to write pidfle {0}.  File exists.'.format(milterconfig.get('PidFile')))
+        raise RuntimeError('Unable to write pidfle {0}.  File exists.'.format(milterconfig.get('PidFile')))