Unable to set SELENIUM_NODE_HOST to {{CONTAINER_IP}} when using swarm/stack

[KZachariassen]

Hi,

I'm trying to deploy selenium on my docker swarm using stack, the problem here is that stack uses go template and will evaluate {{CONTAINER_IP}} on the deployment time. There is currently no way to escape this, so my question is: Could you set the default value of SELENIUM_NODE_HOST
to {{CONTAINER_IP}} so if I don't specify SELENIUM_NODE_HOST in my compose, it will be {{CONTAINER_IP}}?

docker-compose.yml

version: '3.4'

services:
  chrome:
    image: elgalu/selenium
    environment:
      - PICK_ALL_RANDOM_PORTS=true
      - SELENIUM_HUB_HOST=hub
      - SELENIUM_HUB_PORT=4444
      - SELENIUM_NODE_HOST={{CONTAINER_IP}}
      - VNC_FROM_PORT=${VNC_FROM_PORT-40650}
      - VNC_TO_PORT=${VNC_TO_PORT-40700}
      - SCREEN_WIDTH=1300
      - SCREEN_HEIGHT=999
      - VIDEO=${VIDEO-false}
      - GRID=false
      - CHROME=true
      - FIREFOX=false

docker stack deploy -c .\docker-compose.yml selenium
failed to update service selenium_chrome: Error response from daemon: rpc error: code = InvalidArgument desc = expanding env failed: expanding env "SELENIUM_NODE_HOST={{CONTAINER_IP}}": template: expansion:1: function "CONTAINER_IP" not defined

Operating System

• [Linux swarm-manager-1 4.4.0-116-generic Position Firefox / Chrome Browser in upper top, left corner #140-Ubuntu]

Image version

• [latest]

Docker version

• [Docker version 17.12.1-ce, build 7390fc6]

[KZachariassen]

I have solved this really simple(and maybe dirty)
master...krjensen:patch-1

This gives the value USE_CONTAINER_IP the same logic as {{CONTAINER_IP}}

[elgalu]

Good point, we didn't foresee that this would conflict with templating systems in the future. I'm fine with accepting this as a pull request but I would rename USE_CONTAINER_IP with __CONTAINER_IP__

[KZachariassen]

Thank you! I have created a PR.

[elgalu]

Should be fixed now: https://github.com/elgalu/docker-selenium/releases/tag/3.11.0-p11

[uzdik-student]

It took me several hours to figure out this issue on docker swarm, I think it would be great if this solution would be included in docker-compose.md file.

[diemol]

@algakzru feel free to send us a PR to add it there 👍