[🐛 Breaking change]: Harmonized configuration mount point between docker images to /opt/selenium/config.toml

[Trigtrig]

What happened?

This is more an inconsistency instead of a bug but it may lead to confusion when mounting a configuration file.

When setting up a Selenium Grid using Docker we can mount a config.toml for configuration as shown in the documenation. But the mount point differs in the images. Here is a small table showing the current state:

Docker image	mount point
Hub	/opt/selenium/config.toml
NodeDocker	/opt/bin/config.toml
NodeBase	/opt/selenium/config.toml
Standalone	/opt/selenium/config.toml
StandaloneDocker	/opt/bin/config.toml

This may lead to configuration errors since the config.toml is mounted to a valid location in one container but will be silently ignored in another container where the mount point differs. I added a simple hub-node-setup using docker-compose which shows that.

I would suggest to always use the same mount point for config.toml and I'm willing to send in a PR but since this can break existing docker setups, I'm not sure what is the best way to change this.

Command used to start Selenium Grid with Docker (or Kubernetes)

# docker-compose.yml
name: selenium-grid

services:
  selenium-hub:
    image: selenium/hub:4.23.0
    container_name: selenium-hub
    ports:
      - "4444:4444"
    volumes:
      # mounted to /opt/bin/ instead of expected mount point /opt/selenium/ will run the hub by mistake without the desired configuration
      - ./hub-config.toml:/opt/bin/config.toml

  selenium-node:
    image: selenium/node-docker:4.23.0
    container_name: selenium-node
    environment:
      - SE_EVENT_BUS_HOST=selenium-hub
      - SE_EVENT_BUS_PUBLISH_PORT=4442
      - SE_EVENT_BUS_SUBSCRIBE_PORT=4443
      - SE_NODE_GRID_URL=http://selenium-hub:4444
    volumes:
      # same mount point will work for the node
      - ./node-config.toml:/opt/bin/config.toml


# hub-config.toml
[router]
username = "foo"
password = "bar"


# node-config.toml
[server]
host = "selenium-node"
port = "5555"

[node]
detect-drivers = true
override-max-sessions = false

Relevant log output

no relevant log output

Operating System

doesn't matter

Docker Selenium version (image tag)

4.23.0

Selenium Grid chart version (chart version)

no chart involved

[github-actions]

@Trigtrig, thank you for creating this issue. We will troubleshoot it as soon as we can.

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Thank you!

[VietND96]

@diemol, what do you think?

[diemol]

This makes sense. We might have just missed being consistent across images. We should be using /opt/selenium/config.toml in all of them.

[github-actions]

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