Merge pull request #588 from Unrud/daemon

Daemon: Exit first process after server is ready

radicale/__main__.py

@@ -114,26 +114,35 @@ def run():
         exit(1)
 
 
-def serve(configuration, logger):
-    """Serve radicale from configuration."""
-    # Fork if Radicale is launched as daemon
-    if configuration.getboolean("server", "daemon"):
+def daemonize(configuration, logger):
+    """Fork and decouple if Radicale is configured as daemon."""
     # Check and create PID file in a race-free manner
     if configuration.get("server", "pid"):
         try:
+            pid_path = os.path.abspath(os.path.expanduser(
+                configuration.get("server", "pid")))
             pid_fd = os.open(
-                    configuration.get("server", "pid"),
-                    os.O_CREAT | os.O_EXCL | os.O_WRONLY)
-            except:
-                raise OSError(
-                    "PID file exists: %s" % configuration.get("server", "pid"))
+                pid_path, os.O_CREAT | os.O_EXCL | os.O_WRONLY)
+        except OSError as e:
+            raise OSError("PID file exists: %s" %
+                          configuration.get("server", "pid")) from e
     pid = os.fork()
     if pid:
-            sys.exit()
         # Write PID
         if configuration.get("server", "pid"):
             with os.fdopen(pid_fd, "w") as pid_file:
-                pid_file.write(str(os.getpid()))
+                pid_file.write(str(pid))
+        sys.exit()
+    if configuration.get("server", "pid"):
+        os.close(pid_fd)
+
+        # Register exit function
+        def cleanup():
+            """Remove the PID files."""
+            logger.debug("Cleaning up")
+            # Remove PID file
+            os.unlink(pid_path)
+        atexit.register(cleanup)
     # Decouple environment
     os.chdir("/")
     os.setsid()
@@ -143,16 +152,9 @@ def serve(configuration, logger):
         os.dup2(null_out.fileno(), sys.stdout.fileno())
         os.dup2(null_out.fileno(), sys.stderr.fileno())
 
-    # Register exit function
-    def cleanup():
-        """Remove the PID files."""
-        logger.debug("Cleaning up")
-        # Remove PID file
-        if (configuration.get("server", "pid") and
-                configuration.getboolean("server", "daemon")):
-            os.unlink(configuration.get("server", "pid"))
 
-    atexit.register(cleanup)
+def serve(configuration, logger):
+    """Serve radicale from configuration."""
     logger.info("Starting Radicale")
 
     # Create collection servers
@@ -228,6 +230,8 @@ def serve(configuration, logger):
     else:
         # Fallback to busy waiting
         select_timeout = 1.0
+    if configuration.getboolean("server", "daemon"):
+        daemonize(configuration, logger)
     logger.debug("Radicale server ready")
     while not shutdown_program:
         try: