docker-compose - selenium

[jifox]

Is publishing of the port 4444 to the host machine really needed?

---
version: "3"
services:
  ...
  selenium:
    image: selenium/standalone-firefox:latest
    ports: 
      - "4444:4444"
    shm_size: 2g

If its not required to be published on the host machine it should be replaced with:

  selenium:
    image: selenium/standalone-firefox:latest
    expose: 
      - "4444"
    shm_size: 2g

see: Compose File Reference:

Expose ports without publishing them to the host machine - they’ll only be accessible to linked services. Only the internal port can be specified.