Problem with setting wallpaper in plasma-manager module

Help
1

Hi!

I have a nixos “cluster” of three laptops (host-1, -2 and -3), I’m trying to implement different wallpaper based on hostname using home-manager with plasma-manager module. This is my config:

programs.plasma = {
  enable = true;
    workspace = lib.mkMerge [
      (lib.mkIf ("${pkgs.inetutils}/bin/hostname" == "host-1") {
        wallpaperSlideShow = {
          path = ./wallpaper/Ghibli;
          interval = 1; # seconds
        };
        wallpaperBackground.blur = true;
        wallpaperFillMode = "preserveAspectFit";
      })
      (lib.mkIf ("${pkgs.inetutils}/bin/hostname" == "host-2") {
        wallpaper = ./wallpaper/Lexus-LS400.jpg;
        wallpaperBackground.blur = true;
        wallpaperFillMode = "preserveAspectFit";
      })
      (lib.mkIf ("${pkgs.inetutils}/bin/hostname" == "host-3") {
        wallpaper = ./wallpaper/Lexus-LS400.jpg;
        wallpaperBackground.blur = true;
        wallpaperFillMode = "preserveAspectFit";
      })
    ];
  };
};

It lets me rebuild home, but doesn’t set desired wallpaper… Any idea how to trubleshoot it?

Best,
Miro

2

FYI something like this:

    workspace = { 
      wallpaper = ./wallpaper/Lexus-LS400.jpg;
    };

works just fine.

3

This will return the path to the hostname binary, not the machine’s actual hostname.

If you are using Home Manager as a NixOS module you should be able to add { osConfig, ... }: and access the hostname via osConfig.networking.hostName, otherwise your only option is having a separate Home Manager configuration for each machine.

4

Thank you, this is what I was looking for. Now with this config:

    workspace = lib.mkMerge [
    (lib.mkIf (osConfig.networking.hostName == "host-1") {
      wallpaperSlideShow = {
        path = ./wallpaper/Ghibli;
        interval = 5; # seconds
      };
      wallpaperBackground.blur = true;
      wallpaperFillMode = "preserveAspectFit";
    })
    (lib.mkIf (osConfig.networking.hostName == "host-2") {
      wallpaper = ./wallpaper/Lexus-LS400.jpg;
      wallpaperBackground.blur = true;
      wallpaperFillMode = "preserveAspectFit";
    })
    (lib.mkIf (osConfig.networking.hostName == "host-3") {
      wallpaper = ./wallpaper/Lexus-LS400.jpg;
      wallpaperBackground.blur = true;
      wallpaperFillMode = "preserveAspectFit";
    })
    {
      clickItemTo = "open";
      colorScheme = "BreezeDark";
    }
  ];

I get this error:

       … while evaluating the attribute 'condition'
         at /nix/store/1728d3jg85mkz2w2cvk6vi74i30fn6x7-source/lib/modules.nix:1175:15:
         1174|     { _type = "if";
         1175|       inherit condition content;
             |               ^
         1176|     };

       … while selecting an attribute
         at /nix/store/g7pvb6ixxk6ajbw5ra8f8v3i7bjsn74q-source/plasma-manager/plasma-manager.nix:90:16:
           89|     workspace = lib.mkMerge [
           90|     (lib.mkIf (osConfig.networking.hostName == "host-1") {
             |                ^
           91|       wallpaperSlideShow = {

       error: expected a set but found null: null

(This is the output of home-manager switch --verbose --show-trace command)
What does it mean that it expects a set?

5

Then you aren’t using Home Manager as a NixOS module, try the second option I gave you.

I’m not familiar with Home Manager in standalone mode, but I think you can pass --file ./path/to/config.nix to home-manager to specify which configuration you want to use, like this:

home-manager switch --file ./host-1.nix --verbose --show-trace

You can configure each host separately and add your common settings in imports:

# host-1.nix
{
  # Common configuration
  imports = [ ./home.nix ];

  # Specific to "host-1"
  programs.plasma = { ... };
}
6

Okay, thanks.

What are the advantages of using home-manager as a module?

7

One command to build your system and user config, and you can read values from your system config to control your user config.

8

Can any user without sudo privileges modify his home-manager module file?

9

That’s up to you. Set the file and folder permissions as you wish.

10

You just made me switch;)