Don't write to PID file

When running under systemd, PID is known and maintained by systemd.
Process don't have write PIDs to a PID file.

data/etc/plinth/plinth.config

@@ -4,7 +4,6 @@ file_root = /usr/share/plinth
 config_dir = /etc/plinth
 data_dir = /var/lib/plinth
 log_dir = /var/log/plinth
-pid_dir = /var/run
 server_dir = /plinth
 actions_dir = /usr/share/plinth/actions
 doc_dir = /usr/share/doc/plinth
@@ -13,7 +12,6 @@ doc_dir = /usr/share/doc/plinth
 store_file = %(data_dir)s/plinth.sqlite3
 status_log_file = %(log_dir)s/status.log
 access_log_file = %(log_dir)s/access.log
-pidfile = %(pid_dir)s/plinth.pid
 
 [Network]
 host = 127.0.0.1

plinth.config

@@ -4,7 +4,6 @@ file_root = %(root)s
 config_dir = %(file_root)s/data/etc/plinth
 data_dir = %(file_root)s/data/var/lib/plinth
 log_dir = %(file_root)s/data/var/log/plinth
-pid_dir = %(file_root)s/data/var/run
 server_dir = /
 actions_dir = %(file_root)s/actions
 doc_dir = %(file_root)s/doc
@@ -13,7 +12,6 @@ doc_dir = %(file_root)s/doc
 store_file = %(data_dir)s/plinth.sqlite3
 status_log_file = %(log_dir)s/status.log
 access_log_file = %(log_dir)s/access.log
-pidfile = %(pid_dir)s/plinth.pid
 
 [Network]
 host = 127.0.0.1

plinth/__main__.py

@@ -45,9 +45,6 @@ def parse_arguments():
     parser = argparse.ArgumentParser(
         description='Plinth web interface for FreedomBox',
         formatter_class=argparse.ArgumentDefaultsHelpFormatter)
-    parser.add_argument(
-        '--pidfile', default=cfg.pidfile,
-        help='specify a file in which the server may write its pid')
     # TODO: server_dir is actually a url prefix; use a better variable name
     parser.add_argument(
         '--server_dir', default=cfg.server_dir,
@@ -64,7 +61,6 @@ def parse_arguments():
 
     global arguments
     arguments = parser.parse_args()
-    cfg.pidfile = arguments.pidfile
     cfg.server_dir = arguments.server_dir
     cfg.debug = arguments.debug
 
@@ -82,22 +78,14 @@ def setup_server():
     """Setup CherryPy server"""
     logger.info('Setting up CherryPy server')
 
-    # Set the PID file path
-    try:
-        if cfg.pidfile:
-            from cherrypy.process.plugins import PIDFile
-            PIDFile(cherrypy.engine, cfg.pidfile).subscribe()
-    except AttributeError:
-        pass
-
     # Configure default server
-    cherrypy.config.update(
-        {'server.socket_host': cfg.host,
-         'server.socket_port': cfg.port,
-         'server.thread_pool': 10,
-         # Avoid stating files once per second in production
-         'engine.autoreload.on': cfg.debug,
-        })
+    cherrypy.config.update({
+        'server.socket_host': cfg.host,
+        'server.socket_port': cfg.port,
+        'server.thread_pool': 10,
+        # Avoid stating files once per second in production
+        'engine.autoreload.on': cfg.debug,
+    })
 
     application = django.core.wsgi.get_wsgi_application()
     cherrypy.tree.graft(application, cfg.server_dir)

plinth/cfg.py

@@ -33,7 +33,6 @@ actions_dir = None
 doc_dir = None
 status_log_file = None
 access_log_file = None
-pidfile = None
 host = None
 port = None
 use_x_forwarded_host = False
@@ -91,7 +90,6 @@ def read(file_path=None, root_directory=None):
         ('Path', 'doc_dir', 'string'),
         ('Path', 'status_log_file', 'string'),
         ('Path', 'access_log_file', 'string'),
-        ('Path', 'pidfile', 'string'),
         ('Path', 'server_dir', 'string'),
         ('Network', 'host', 'string'),
         ('Network', 'port', 'int'),

plinth/tests/test_cfg.py

@@ -126,7 +126,7 @@ class TestCfg(unittest.TestCase):
         """Compare two sets of configuration values."""
         # Note that the count of items within each section includes the number
         # of default items (1, for 'root').
-        self.assertEqual(13, len(parser.items('Path')))
+        self.assertEqual(11, len(parser.items('Path')))
         self.assertEqual(parser.get('Path', 'root'), cfg.root)
         self.assertEqual(parser.get('Path', 'file_root'), cfg.file_root)
         self.assertEqual(parser.get('Path', 'config_dir'), cfg.config_dir)
@@ -139,7 +139,6 @@ class TestCfg(unittest.TestCase):
                          cfg.status_log_file)
         self.assertEqual(parser.get('Path', 'access_log_file'),
                          cfg.access_log_file)
-        self.assertEqual(parser.get('Path', 'pidfile'), cfg.pidfile)
 
         self.assertEqual(5, len(parser.items('Network')))
         self.assertEqual(parser.get('Network', 'host'), cfg.host)