Making the "compose" subcommand available to docker CLI in fish shell

Development tools today are very complicated to install and deal with, the foremost of which is the docker CLI. You install it via shell script on most systems and if you want docker compose, you need to install it separately. In some systems, it gets added as a subcommand, so that the docker binary can handle it, but on others you specifically have to call docker-compose, a single script, without spaces. If you try to run the compose subcommand in this case, docker will complain about it not being available.

The solution: using a fish function!

function docker -d "docker command with compose subcommand" -w docker
  if match "$argv[1]" "compose"
    docker-compose $argv[2..-1]
  else
    command docker $argv
  end
end

Save this in a file called docker.fish in your fish function directory (it’s in $XDG_CONFIG_DIR/fish/functions, or ~/.config/fish/functions).
-d gives the description of the function, and -w indicates that the function is wrapping the docker command, giving access to useful completions. The command fish built-in ensures that the function does not call itself, but rather the real docker binary.

Update:

Turns out all of this was unnecessary, and the only reason docker compose wasn't showing up as a subcommand is because it could not find the compose plugin

When you download docker-compose you might get this helpful tip

# Compose is a Docker plugin. For Docker to find the plugin, add "cliPluginsExtraDirs" to ~/.docker/config.json:
  "cliPluginsExtraDirs": [
      "/Users/arnavandrewjose/homebrew/lib/docker/cli-plugins"
  ]