support custom location for database persistent statefile (defaults to "capport.state" in cwd)

capport-example.yaml

@@ -11,3 +11,4 @@ server-names:
 - ...
 api-port: 8000
 controller-port: 5000
+database-file: capport.state

src/capport/comm/hub.py

@@ -299,11 +299,11 @@ class Hub:
         self._hostname = socket.getfqdn()
         self._app = app
         self._is_controller = is_controller
-        state_filename: typing.Optional[str]
+        state_filename: str
         if is_controller:
-            state_filename = 'capport.state'
+            state_filename = config.database_file
         else:
-            state_filename = None
+            state_filename = ''
         self.database = capport.database.Database(state_filename=state_filename)
         self._anon_context = ssl.SSLContext()
         # python ssl doesn't support setting tls1.3 ciphers yet, so make sure we stay on 1.2 for now to enable anon

src/capport/config.py

@@ -23,6 +23,7 @@ class Config:
     session_timeout: int  # in seconds
     api_port: int
     controller_port: int
+    database_file: str  # empty str: disable database
     debug: bool
 
     @staticmethod
@@ -58,6 +59,7 @@ class Config:
             session_timeout=data.pop('session-timeout', 3600),
             api_port=data.pop('api-port', 8000),
             controller_port=data.pop('controller-port', 5000),
+            database_file=str(data.pop('database-file', 'capport.state')),
             debug=data.pop('debug', False)
         )
         if data:

src/capport/database.py

@@ -139,7 +139,7 @@ class NotReadyYet(Exception):
 
 
 class Database:
-    def __init__(self, state_filename: typing.Optional[str] = None):
+    def __init__(self, state_filename: str = ""):
         self._macs: dict[cptypes.MacAddress, MacEntry] = {}
         self._state_filename = state_filename
         self._changed_since_last_cleanup = False