change to mongo 3.4

docker-compose.yml

@@ -3,10 +3,12 @@ version: '2'
 services:
 
   wekandb:
-    image: mongo:latest
+    image: mongo:3.4
     container_name: wekan-db
     restart: always
     command: mongod --smallfiles --oplogSize 128
+    networks:
+      - wekan-tier
     expose:
       - 27017
     volumes:
@@ -17,6 +19,8 @@ services:
     image: wefork/wekan
     container_name: wekan-app
     restart: always
+    networks:
+      - wekan-tier
     build:
       context: .
       dockerfile: Dockerfile
@@ -31,11 +35,15 @@ services:
     environment:
       - MONGO_URL=mongodb://wekandb:27017/wekan
       - ROOT_URL=http://localhost
-    links:
-      - wekandb
     depends_on:
       - wekandb
 
 volumes:
   wekan-db:
     driver: local
+  wekan-db-dump:
+    driver: local
+
+networks:
+  wekan-tier:
+    driver: bridge