Error contacting service, status = undefined #356

I have a playground UI that I have build from this path https://github.com/apache/openwhisk/tree/master/core/standalone/src/main/resources/playground using nginx as base image which proxy_pass to ui/index.html. I used this image in this https://github.com/apache/openwhisk-devtools/blob/master/docker-compose/docker-compose-lean.yml. I can access UI via ip-address:3232. I'm now trying to link it to controller but when I try to run function in ui, I'm getting this error Error contacting service, status = undefined. I changed API_HOST in ui's code as http://ip-address:8080 and namespace to guest.
My ui service looks like this in docker-compose.yml

ui:
    image: hub_username/repository:tag
    ports:
      - 3232:80
    depends_on:
      - controller