docker-compose doesn't install as a pluging

[doughsay]

Output of brew config

HOMEBREW_VERSION: 4.4.17
ORIGIN: https://github.com/Homebrew/brew
HEAD: 55f399c10dc7e6cc07497bdfccdecc96329e3b57
Last commit: 2 days ago
Branch: stable
Core tap JSON: 21 Jan 20:48 UTC
Core cask tap JSON: 21 Jan 20:48 UTC
HOMEBREW_PREFIX: /opt/homebrew
HOMEBREW_CASK_OPTS: []
HOMEBREW_MAKE_JOBS: 10
Homebrew Ruby: 3.3.7 => /opt/homebrew/Library/Homebrew/vendor/portable-ruby/3.3.7/bin/ruby
CPU: deca-core 64-bit arm_firestorm_icestorm
Clang: 16.0.0 build 1600
Git: 2.48.1 => /opt/homebrew/bin/git
Curl: 8.7.1 => /usr/bin/curl
macOS: 15.2-arm64
CLT: 16.2.0.0.1.1733547573
Xcode: 16.2
Rosetta 2: false

Output of brew doctor

Your system is ready to brew.

Description of issue

I'm trying to get a non-docker-dektop (command-line only) setup working using homebrew. And ultimately everything works fine, this is what I've done:

brew install colima docker docker-compose docker-credential-helper
colima start

this creates a working docker setup with compose, but, to use docker compose you have to use the old style:

docker-compose <command>

instead of the new plugin way of doing things, e.g.:

docker compose <command>

I just wanted to start a discussion to know why this is the case, if there is any way for us to update to the newer way, or if this is some limitation we can't work around right now.

Thanks.

[alebcay]

docker looks for plugins in the following order](https://github.com/docker/cli/blob/master/cli-plugins/manager/manager_unix.go#L8-L12):

1. The "cli-plugins" directory inside the CLIs config-directory (usually "~/.docker/cli-plugins").
2. Additional plugin directories as configured through [ConfigFile.CLIPluginsExtraDirs].
3. Platform-specific defaultSystemPluginDirs: /usr/local/lib/docker/cli-plugins, /usr/local/libexec/docker/cli-plugins, /usr/lib/docker/cli-plugins, /usr/libexec/docker/cli-plugins, defined here

Options 1 and 2 above involve modifying/installing things outside of the Homebrew prefix (in this case, requires installing the plugin into ~/.docker/cli-plugins or manipulating the config file at ~/.docker/config.json), and this is generally avoided where possible (to avoid the possibility of trampling/breaking users' config, data, etc.).

For option 3, Golang does provide a mechanism to override/set the value of variables in some situations. But the variable must be public, and it must be a string type. In this case, the variable is private to the package/module and it is a string slice type. One alternative is to directly patch the source code to add the locations where Homebrew installs the plugins, but to the extent possible we try to avoid carrying patches, because it makes maintaining the package more difficult when patches break (due to the upstream source changing).

Hopefully that gives some context behind the status quo.

[carlocab]

Have you tried using the Caveats shown to you when you did brew install docker-compose? You can see them again with brew info docker-compose:

❯ brew info docker-compose
==> docker-compose: stable 2.32.4 (bottled), HEAD
[snip]
==> Caveats
Compose is a Docker plugin. For Docker to find the plugin, add "cliPluginsExtraDirs" to ~/.docker/config.json:
  "cliPluginsExtraDirs": [
      "/opt/homebrew/lib/docker/cli-plugins"
  ]
==> Analytics
[snip]

[doughsay]

Oh my gosh, so embarrassing, I totally missed it 😅 I'm usually so good about noticing the caveats. Thank you for pointing it out, it works totally as expected!