fix: the web service listens on the internal address, the external address or both.

debian-package/src/usr/lib/vpn-router/web

@@ -1,5 +1,5 @@
 #!/usr/bin/python3
-"""Serve the status of the router on its internal address.
+"""Serve the status of the router on its internal address, its external address or both, as web.listen sets.
 
 Run by vpn-router-web.service. Users are managed with vpnrouter_users, the module that
 vpn-router-user uses too.
@@ -27,7 +27,7 @@ token of vpn-router-token has the admin claim and names no user; it may call eve
 add or take out its members, and remove one of its members. These paths and /auth are not
 served (404) while the key does not exist. /auth is limited to AUTH_LIMIT calls per client
 address in AUTH_WINDOW seconds; the address of a call from one of web.trusted_proxies, by
-default the address the service listens on, is the last entry of its X-Forwarded-For header.
+default the address the call came in on, is the last entry of its X-Forwarded-For header.
 
 / and /status show only the status: whether the services run, the package version and the
 installed version of vpn-router-manager (manager_version, null when it is not installed), whether
@@ -40,10 +40,11 @@ logging each failure. Then it listens. Its unit starts it only once wait-for-lib
 in the linker cache, where psycopg looks it up.
 
 The service needs nothing else to start and does not end on its own. Every DISCOVERY_SECONDS it
-works out the internal address from /etc/vpn-router/vpn-router.json as general.mode directs,
-with web.port and web.enabled (vpnrouter_net.web_listen), and runs the server there
-(vpnrouter_serve.serve): it starts it, moves it when the address or the port changes, and stops
-it while the service is disabled or the address is not known. Every request reads what it needs when it is made: the signing
+works out from /etc/vpn-router/vpn-router.json the addresses of the interfaces web.listen names,
+internal, external or both, as general.mode directs, with web.port and web.enabled
+(vpnrouter_net.web_listen), and runs a server on each (vpnrouter_serve.serve): it starts them,
+moves them when an address or the port changes, and stops them while the service is disabled or
+no address is known. Every request reads what it needs when it is made: the signing
 key, the configuration, and the features of the router and the facts shown by /config from
 /run/vpn-router/web.json, which vpn-router-setup writes. Before setup has written that file
 the router has no features, and /config shows no configuration or interfaces.