feat: make DHT port configurable

daemon/Dockerfile

@@ -25,6 +25,7 @@ ENV RT_TRACKER_UDP="yes"
 ENV RT_MIN_PORT=50000
 ENV RT_MAX_PORT=50000
 ENV RT_PROTO_DHT="disable"
+ENV RT_DHT_PORT=6881
 ENV RT_PROTO_PEX="no"
 ENV RT_MAX_UP=100
 ENV RT_MAX_UP_GLOBAL=250

daemon/src/rtorrent.rc

@@ -15,6 +15,7 @@ network.port_random.set = no
 # Enable tracker-less torrents but vulnerable to passive sniffing
 # DHT and PEX are always disabled for private torrents
 dht.mode.set = (system.env,RT_PROTO_DHT)
+dht.port.set = (system.env,RT_DHT_PORT)
 protocol.pex.set = (system.env,RT_PROTO_PEX)
 
 trackers.use_udp.set = (system.env,RT_TRACKER_UDP)