Allow extending dnsmasq by providing custom configuration. (#162)

* Allow extending dnsmasq by providing custom configuration.

* update README with optional dnsmasq config

README.md

@@ -167,18 +167,20 @@ docker create \
     --network host \
     --cap-add NET_ADMIN \
     --volume /data:/data \
+    # Optional directory for mounting dnsmasq configurations
+    --volume /etc/dnsmasq.d:/etc/dnsmasq.d \
     --env SUBSPACE_HTTP_HOST="subspace.example.com" \
-	# Optional variable to change upstream DNS provider
+    # Optional variable to change upstream DNS provider
     --env SUBSPACE_NAMESERVERS="1.1.1.1,8.8.8.8" \
-	# Optional variable to change WireGuard Listenport
+    # Optional variable to change WireGuard Listenport
     --env SUBSPACE_LISTENPORT="51820" \
   # Optional variables to change IPv4/v6 prefixes
     --env SUBSPACE_IPV4_POOL="10.99.97.0/24" \
     --env SUBSPACE_IPV6_POOL="fd00::10:97:0/64" \
-	# Optional variables to change IPv4/v6 Gateway
+    # Optional variables to change IPv4/v6 Gateway
     --env SUBSPACE_IPV4_GW="10.99.97.1" \
     --env SUBSPACE_IPV6_GW="fd00::10:97:1" \
-	# Optional variable to enable or disable IPv6 NAT
+    # Optional variable to enable or disable IPv6 NAT
     --env SUBSPACE_IPV6_NAT_ENABLED=1 \
   # Optional variable to disable DNS server. Enabled by default.
   # consider disabling DNS server, if supporting international VPN clients
@@ -203,6 +205,7 @@ services:
    container_name: subspace
    volumes:
     - /opt/docker/subspace:/data
+    - /opt/docker/dnsmasq:/etc/dnsmasq.d
    restart: always
    environment:
     - SUBSPACE_HTTP_HOST=subspace.example.org

entrypoint.sh

@@ -203,6 +203,9 @@ if [[ ${SUBSPACE_DISABLE_DNS} == "0" ]]; then
 
     # Never forward addresses in the non-routed address spaces.
     bogus-priv
+    
+    # Allow extending dnsmasq by providing custom configurations.
+    conf-dir=/etc/dnsmasq.d
 DNSMASQ
 
     mkdir -p /etc/service/dnsmasq