Re-add pid file

adsms.py

@@ -83,4 +83,13 @@ if __name__ == "__main__":
     args = parser.parse_args()
 
     config = load_config(args.config_file)
+
+    try:
+        if config["pid_file"]:
+            with open(config["pid_file"], "w+") as f:
+                f.write(str(os.getpid()))
+
         run(config)
+    finally:
+        if config["pid_file"]:
+            os.unlink(config["pid_file"])

example_config.json

@@ -2,7 +2,7 @@
     "textbelt_key": "API_KEY",
     "data": "http://localhost/tar1090/data/aircraft.json",
     "tracker": "https://globe.theairtraffic.com/",
-    "database": "/var/lib/adsms/subscriptions.db",
+    "database": "/var/lib/adsms/subscribers.db",
     "pid_file": "/var/lib/adsms/pid.txt",
     "max_age": 30,
     "min_disappearance": 120,