feat: homebrew on image

[m2Giles]

No description provided.

[m2Giles]

ToDo:

Better handling of permissions for lower to upper directory.

Right now the lower dir is owned by root. How do we make sure that brew can modify things without making duplicates of everything in the mutable upper directory. Or if duplication is fine getting that immediate chown fired.

But brew is on image.

[castrojo]

Ok to replicate the bluefin-cli experience we'll need:

eza
fd
ripgrep (we may want ugrep in addition or instead of?)
zoxide

Things already on the image that we'll probably want to leave there but maybe move over later?:

atuin
fish
fzf
starship
zsh

We'll need to test root things too, for example not sure if rclone/restic is worth swapping over if they can't access things to backup, etc.

[m2Giles]

Root can use homebrew binaries if you have an interactive login shell.

For systemd services you can specify the binary with the full path. So something like rclone would be /home/linuxbrew/.linuxbrew/bin/rclone instead of /usr/bin/rclone.

[m2Giles]

We'll need to adjust the brew just commands from config to not mess with this.

[m2Giles]

Assumptions made:

1. The brew user is UID 1000. This makes sense for our systems:
   1. The Bluefin ISO will create the first user as a wheel user and UID 1000.
   2. The Aurora ISO needs the user to go into the advanced options to change the UID.
2. Single User system.
   1. Brew expects to be owned by a single user. Since most of our systems are single user our setup should be fine. However, for a multi-user system, UID 1000 needs to be the brew user.
3. Auto Updates
   1. Brew controls if it should auto-update based on an environment variable. Since brew and the portable ruby are on image, we do not want this to occur. This means that if a user goes awhile without rebooting, brew will not update.
   2. Need to inspect how auto upgrades work since normally you update prior to running upgrade. This appears to work on my host system without running brew update.

[m2Giles]

Switching from the downloaded version of homebrew to the version installed by bluefin-cli, drops the duplicated data size down to 20 MB.

[m2Giles]

#1301

This needs to be added.