Docker Composer Override of the Command for the CLI Container

Docker Compose has an ability to configure which command to run on cli container start.

services:
  cli:
    command: bundle exec thin -p 3000

The command can also be in a list:

services:
  cli:
    command: ["bundle", "exec", "thin", "-p", "3000"]

This can be useful for automatic services initialization, such as:

services:
  cli:
    # Using nodemon for live reload
    command: ["bash", "-lc", "nodemon index.js"]

Note bash -lc, not just bash -c, as login shell initializes docker user environment.