home-manager: check FQDN for '--flake .' attribute

[gauravjuvekar]

Description

Since nixpkgs commit 993baa587c4b82e791686f6ce711bcd4ee8ef933, networking.hostName is not allowed to be a FQDN.

Add hostname --fqdn to the default flake attribute names that are searched.

If

netorking.hostname = "hostname";
networking.domain = "example.com";

is set in the system NixOS configuration, this allows defining

homeConfigurations."username@hostname.example.com" = ...

and still use

home-manager switch --flake .

instead of having to type out

home-manager switch --flake .#$(whoami)@$(hostname --fqdn)

Checklist

• Change is backwards compatible.

  • Technically no if someone happens to have both homeConfigurations."username@hostname" and homeConfigurations."username@hostname.example.com".

• Code formatted with ./format.

• Code tested through nix-shell --pure tests -A run.all or nix develop --ignore-environment .#all using Flakes.

• Test cases updated/added. See example.

• Commit messages are formatted like

  {component}: {description}
  
  {long description}
  

  See CONTRIBUTING for more information and recent commit messages for examples.

• If this PR adds a new module

  • Added myself as module maintainer. See example.

Maintainer CC

[rycee]

Thanks, looks good! Merged to master now 🙂

[ilyagr]

After this PR (I believe), I'm getting the following error on Mac OS:

$ uname -a
Darwin macaw.local 23.5.0 Darwin Kernel Version 23.5.0: Wed May  1 20:14:38 PDT 2024; root:xnu-10063.121.3~5/RELEASE_ARM64_T6020 arm64 arm Darwin
$ home-manager switch --impure
hostname: illegal option -- -
usage: hostname [-fs] [name-of-host]
Starting Home Manager activation
Activating checkFilesChanged
Activating checkLaunchAgents
Activating checkLinkTargets
Activating writeBoundary
Activating installPackages
nix profile remove /nix/store/b6g3p868a8lkzdq7rnf12nj9njm4szca-home-manager-path
removing 'home-manager-path'
Activating linkGeneration
Cleaning up orphan links from /Users/ilyagr
No change so reusing latest profile generation 98
Creating home file links in /Users/ilyagr
Activating onFilesChange
Activating setupLaunchAgents

Update: Don't be too alarmed, the error does not prevent home-manager switch from working. It's merely an annoyance, the command still works after showing the error.

(I am not sure how to find out the exact commit of home-manager I'm using, but I started seeing the error recently, I believe after I updated home-manager today, and this PR looks extremely suspicious)

[gauravjuvekar]

Yep, this PR is the likely cause.
I'll change it to hostname -f as seems like macos doesn't support the long style option name --fqdn (based on the usage: line)

[gauravjuvekar]

#5471

[bryango]

If the hostname is not set in /etc/hosts, the command may fail with:

$ hostname -f
hostname: Unknown host

This shows up in the home-manager switch printout and is mildly annoying. Could it be changed to:

hostname -f 2>/dev/null

to suppress this inconsequential warning? Thank you!

[gauravjuvekar]

Ack, I'll make a PR some time this week. Could you file a separate issue for this and tag me?