implemented daemon

naxalnet is now a daemon! When run from systemd, it checks for new
devices or removal of devices and reloads the wifi configuration.
Updated the systemd service and changed Type to notify. Unfortunately,
there is some problem with logging. The messages from naxalnet.iwd could
not be found in the systemd journal or while running without --systemd.

naxalnet.service

@@ -17,28 +17,23 @@ After=NetworkManager.service
 After=wpa_supplicant.service
 
 [Service]
-# TODO: change to notify when naxalnet becomes a daemon
+Type=notify
-Type=oneshot
+NotifyAccess=all
-RemainAfterExit=yes
 Restart=on-failure
 RestartSec=2sec
-# IWD takes some time to find devices.
-# If naxalnet is run before iwd finds devices,
-# naxalnet cannot start a mesh network but exits without errors.
-# So, we give a 2s delay.
-ExecStartPre=/usr/bin/sleep 2
 ExecStart=/usr/bin/naxalnet --systemd
 # Reload systemd-networkd after naxalnet exits
 ExecStartPost=/usr/bin/networkctl reload
 # Delete all files starting with mesh.* in /run/systemd/network
-ExecStop=/usr/bin/find /run/systemd/network -type f -delete -name "mesh.*"
+ExecStopPost=/usr/bin/find /run/systemd/network -type f -delete -name "mesh.*"
 # Delete the interfaces created...
 ExecStopPost=/usr/bin/networkctl delete bridge0 bat0
 # ... and reload the configuration files.
 ExecStopPost=/usr/bin/networkctl reload
-
+# naxalnet already logs to systemd journal so we don't need
-# Disable python buffering
+# stdout and stderr.
-Environment=PYTHONUNBUFFERED=1
+StandardOutput=null
+StandardError=null
 
 [Install]
 WantedBy=multi-user.target

naxalnet/__init__.py

@@ -35,4 +35,4 @@ See README.md for documentation.
 #
 # In case you forgot to change the version, skip the number
 # and put the next number in the next commit.
-__version__ = "0.3.0a2.dev3"
+__version__ = "0.3.0a2.dev4"

naxalnet/config.py

@@ -61,8 +61,6 @@ from configparser import ConfigParser
 from argparse import ArgumentParser, Namespace
 from naxalnet.default import CONFIG, CONFIG_FILES, CONFIG_DIRS
 
-# from naxalnet.log import logger
-
 
 def get_config_files():
     """

naxalnet/daemon.py

@@ -22,38 +22,50 @@ The daemon part. This is currently under construction.
 """
 
 import logging
-from naxalnet.iwd import IWD
+from dasbus.loop import EventLoop
+from naxalnet.iwd import IWD, IWD_DEVICE_INTERFACE
+
+logger = logging.getLogger(__name__)
 
 
 class Daemon:
     """implements the daemon part"""
 
-    logger = logging.getLogger(__name__)
-
     def __init__(self):
-        iwd = IWD()
+        self.loop = EventLoop()
-        self.device_add_call = self.device_remove_call = None
+        self.iwd = IWD()
 
-    def on_device_add(self, callback):
+    def on_device_add(self, path, data):
         """
-        run the given callback with no arguments
+        this function will be run every time a device is added
-        every time a device is added
         """
-        self.device_add_call = callback
+        if IWD_DEVICE_INTERFACE in data:
+            logger.debug("New device %s found", str(data[IWD_DEVICE_INTERFACE]["Name"]))
+            logger.info("Reloading")
+            self.callback()
 
-    def on_device_remove(self, callback):
+    def on_device_remove(self, path, data):
         """
-        run the given callback with no arguments
+        this function will be run every time a device is removed
-        every time a device is removed
         """
-        self.device_remove_call = callback
+        if IWD_DEVICE_INTERFACE in data:
+            logger.debug("A device was removed")
+            logger.info("Reloading")
+            self.callback()
 
-    def register_callbacks(self):
+    def add_callback(self, callback):
         """
-        register the callbacks with D-Bus
+        register the callback with D-Bus so that callback is
+        run every time a device is added or removed
         """
+        self.callback = callback
+        proxy = self.iwd._proxy
+        proxy.InterfacesAdded.connect(self.on_device_add)
+        proxy.InterfacesRemoved.connect(self.on_device_remove)
 
     def start(self):
         """
         start the daemon
         """
+        logger.debug("Starting daemon")
+        self.loop.run()

naxalnet/iwd.py

@@ -59,7 +59,6 @@ and what they mean:
 import logging
 from dasbus.connection import SystemMessageBus
 
-# from naxalnet.log import logger
 logger = logging.getLogger(__name__)
 
 IWD_BUS = "net.connman.iwd"

naxalnet/scripts.py

@@ -32,13 +32,16 @@ from pathlib import Path
 from shutil import copy
 from dasbus.error import DBusError
 from systemd import journal
+from systemd.daemon import notify
 from naxalnet import __version__
 from naxalnet.iwd import Adapter, Device, IWD
 from naxalnet.config import parse_args
+from naxalnet.daemon import Daemon
 
-# from naxalnet.log import logger
+# Do not use getLogger(__name__) here.
-
+# getLogger() without any args will give us
-logger = logging.getLogger(__name__)
+# the root logger, which is waht we need.
+logger = logging.getLogger()
 args = parse_args()
 
 
@@ -50,6 +53,7 @@ def copy_files():
     See man:systemd.network(5)
     """
     try:
+        notify("STATUS=Configuring the network...")
         logger.info("Copying network config files")
         dest = Path(args.networkd_runtime_dir)
         src = Path(args.networkd_config_dir)
@@ -72,6 +76,7 @@ def setup_devices():
     is connected or removed.
     """
     try:
+        notify("STATUS=Setting up mesh...")
         iwd = IWD()
         devices = iwd.get_devices()
         adhoc_devices = []
@@ -122,11 +127,12 @@ def setup_devices():
                     ap_adapter.power_on()
                     ap_device.start_ap(args.ap_ssid, args.ap_passwd)
             else:
-                logger.info("Not setting up WiFi AP.")
+                logger.warning("Not setting up WiFi AP.")
         else:
             logger.warning(
                 "No device found to setup mesh. Make sure a WiFi adapter is connected"
             )
+
     except DBusError:
         logger.exception("Error while communicating with iwd")
         sys.exit(4)
@@ -170,7 +176,7 @@ def main():
 
     # if --systemd is given, log to systemd journal
     if args.systemd:
-        logger.setLevel(level=logging.DEBUG)
+        logging.basicConfig(level=logging.DEBUG)
         logger.addHandler(journal.JournalHandler())
     else:
         logging.basicConfig(level=loglevel)
@@ -178,6 +184,17 @@ def main():
     copy_files()
 
     setup_devices()
+    # Notify systemd that naxalnet is ready.
+    # see man:sd_notify(3)
+    notify("READY=1")
 
-    # naxalnet prints Bye if no errors occured
+    # Start the daemon so that setup_devices() is called every
+    # time a device is connected or removed.
+    daemon = Daemon()
+    daemon.add_callback(setup_devices)
+
+    notify("STATUS=Waiting for changes")
+    daemon.start()
+
+    # naxalnet prints Bye while exiting.
     logger.info("Bye")