Stream: nix

Topic: Multiuser and multihost configuration

Eelco van Vliet (Feb 09 2025 at 16:23):

I have created a fork of the configuration by srid here https://github.com/eelcovv/nixos-config . I'm pretty satisfied because I can create a setup for different computers.

However, today I am trying to do something which is almost complete. I have a configuration for an external program called ptgui which I want to load for only one hostname name. Therefore, in the file modules/home/default.nix i am trying to added a filtrer on what to import based on the username and hostname. For some reason this does seem to work . I have now:

let
  hostName = builtins.getEnv "HOST";
  userName = builtins.getEnv "USER";
  isEelco = ((builtins.match ".*eelco.*" userName) != null);
  isTongfang = ((builtins.match ".*tongfang.*" hostName) != null); # userName == "eelco";
in
{

  home.stateVersion = "22.11";
  imports =
    (
      if true then [
        ./profiles/development.nix
        ./profiles/datascience.nix
        ./profiles/engingeering.nix
      ] else [ ]
    )
    ++
    (
      if isTongfang then [
        ./all/ptgui
      ] else [ ]
    )
    ++
    [
      ./profiles/graphics.nix
      ./profiles/internet.nix
      ./profiles/multimedia.nix
      ./profiles/officetools.nix
      ./profiles/publishing.nix
      ./profiles/security.nix
      ./profiles/socialmedia.nix
      ./profiles/systemtools.nix
      ./all/tmux.nix
      ./all/neovim
      # ./helix.nix
      ./all/ssh.nix
      ./all/starship.nix
      ./all/terminal.nix
      ./all/nix.nix
      ./all/git.nix
      ./all/direnv.nix
      ./all/zellij.nix
      # ./nushell.nix
      ./all/just.nix
      ./all/powershell.nix
      ./all/juspay.nix
      # conditional imports

      # Comment out because of annoying password prompts
      # ./all/_1password.nix
    ];

}

the idea is that i only want to load ptgui when the hostname is tongfang. But this does seem to work. Anybody has any suggestion what i can do? I dont get an error, i only dont include ptgui. If i set the logicatl expression hard to true it does work. Can i filter on hostname and username in this way? Any hints appreciated

Srid (Feb 10 2025 at 13:26):

Flakes are pure, so I don't think the likes of builtins.getEnv will work.

Srid (Feb 10 2025 at 13:28):

Username should be available from home-manager config or your custom config (e.g.: https://github.com/juspay/nixos-unified-template/pull/129 )

Hostname and other stuff you can pass in specialArgs, unless you are on NixOS, then it is config.networking.hostName

Srid (Feb 10 2025 at 13:29):

Note that here,

https://github.com/srid/nixos-unified/blob/be4ce51cae1dda99e8fd57036215b19ef37bd7fd/examples/home/flake.nix#L24

You can also say legacyPackages.homeConfigurations."${myUserName}@${myHostname}" (the activate app will recognize that). And perhaps you can pass that as specialArg or something, from toplevel.

Last updated: Feb 21 2025 at 17:45 UTC