[add] added support for custom nginx location config files

docker-compose.yml

@@ -17,16 +17,21 @@ services:
     image: proxy
     container_name: proxy
     ports:
-      - "80:8080"
-      - "443:8443"
+      - "9980:8080"
+      - "9443:8443"
     networks:
       - service_web
       - service_certbot
+      - backend_proxy
     volumes:
       # cert volume
       - proxy_ssl:/service/ssl:ro
       # /.well-known/acme-challenge/ volume
       - proxy_certbot:/service/html/certbot:ro
+      # custom config mount
+      # can be used to set custom locations for upstream server
+      # has to have the same name as the upstream server to be loaded
+      - ./files/upstream_configs:/upstream_configs:ro
   
   certbot:
     depends_on:
@@ -98,4 +103,7 @@ networks:
   service_web:
     name: service_web
   service_certbot:
-    name: service_certbot
+    name: service_certbot
+  backend_proxy:
+    name: backend_proxy
+    external: true