Environment Variables and brew services

[robsdudeson]

Output of brew config

HOMEBREW_VERSION: 4.5.4
ORIGIN: https://github.com/Homebrew/brew
HEAD: 54c8b127ea2263fbbaf1354e3d8d86025e387ea6
Last commit: 5 days ago
Branch: stable
Core tap JSON: 04 Jun 20:09 UTC
Core cask tap JSON: 04 Jun 20:09 UTC
HOMEBREW_PREFIX: /opt/homebrew
HOMEBREW_BUNDLE_USER_CACHE: /Users/robsdudeson/.cache/bundle
HOMEBREW_CASK_OPTS: []
HOMEBREW_EDITOR: nvim
HOMEBREW_MAKE_JOBS: 16
Homebrew Ruby: 3.4.4 => /opt/homebrew/Library/Homebrew/vendor/portable-ruby/3.4.4/bin/ruby
CPU: 16-core 64-bit arm_brava
Clang: 17.0.0 build 1700
Git: 2.49.0 => /opt/homebrew/bin/git
Curl: 8.7.1 => /usr/bin/curl
macOS: 15.5-arm64
CLT: 16.4.0.0.1.1747106510
Xcode: N/A
Rosetta 2: false

Output of brew doctor

Your system is ready to brew.

Description of issue

Question

I'm curious if others would find it reasonable or useful to have an optional way for brew services to specify environment variables that all tools run by brew services would pick up and use when running.

Proposal

Use a new env var HOMEBREW_SERVICES_ENV_FILE with a default of HOMEBREW_USER_CONFIG_HOME/.env

This .env file would contain a list of environment variables that the user would want exported to services run via homebrew.

Each environment variable could have a static value set similar to bash syntax (i.e. VAR='some value') or just declared as the variable symbol and resolved to the running shell's value. (i.e. VAR)

These environment variables would then either need to be appended to the .plist definitions of each service or set via launchctl setenv prior to running/starting homebrew services.

Context

I'm a heavy user of the XDG Spec for home directory organization and specify the respective XDG_* environment vars on my Mac so tools that support it will respect them.

I found that the colima service created ~/.colima when running via brew services despite my setting of the appropriate XDG_CONFIG_HOME. This was surprising to me because launching the tool via a terminal created a directory at the expected location (~/.config/colima).

Root Cause

This prompted a deep dive into what was going on. I determined the root cause of this to be that launchd does not run a login shell and therefore does not know about my custom definitions in .bash_profile, .zprofile, etc.

I found that launchd provides a couple of ways to deal with this...

1. Set the respective env vars in the EnvironmentVariables dictionary in the service .plist file
2. Use launchctl setenv prior to running the service.

Pitfalls

Both of these have pitfalls with respect to homebrew managed services.

Option 1 has the issue that when issuing brew services restart <service> the .plist file is regenerated to the maintainer's version, wiping out any customizations I made.

Option 2 has the issue that launchctl setenv must be re-run after a reboot and there is no simple way, within the context of launchd/launchctl, to ensure that they are set before running other services.

[manuel-koch]

I struggle with a similar scenario:

I want to configure env vars or command line options for ollama and despite editing the *.plist file of the service, any brew services start ollama or brew services restart ollama wipes away any configuration changes.

[mcamou]

Yes please, I have the same issue with ollama. I've tried using launchctl setenv and then brew services restart ollama but it does not seem to work.