let nginx proxy route swarm viz container

dind_swarm.yml

@@ -18,8 +18,8 @@ services:
     volumes:
       - /mnt/nopaque:/mnt/nopaque
   viz:
+    environment:
+      - VIRTUAL_HOST=viz.localhost
     image: dockersamples/visualizer:latest
-    ports:
-      - 8080:8080
     volumes:
       - /var/run/docker.sock:/var/run/docker.sock