Nix Zellij

A quick blog post on using nix with Zellij.

Where I can't get my favourite Tmux configuration going, I often turn to Zellij. Zellij is a great alternative to Tmux and offers some cool elements, which I may revisit in a future blog post. For now, I just want to outline how to perform a similar layout configuration to the Tmux one I recently wrote.

You can amend the configuration used to setup the screen however you wish. Just amend the dev.kdl script to realign your screen layout however you want.

Nix Scripts

To get started we need to define an external script to represent the environment requirement. Zellij uses kdl files to represent screen layouts, so the configuration slightly different to Tmux.

1. Lets create a zellij layout script dev.kdl:

    1layout {
    2   tab name="Go Dev" focus=true {
    3     pane split_direction="vertical" {
    4       pane {
    5         name "Terminal#1"
    6       }
    7       pane split_direction="horizontal" {
    8         pane {
    9           name "Termina#2"
   10         }
   11         pane  {
   12           name "Terminal#3"
   13         }
   14       }
   15     }
   16   }
   17}
   

   In the above dev.kdl script we create a new layout.

2. We now need to tell Nix to add the dev.kdl external script as a dependency.

   1let
   2  # External Script: This reads './dev.kdl' and puts it into a binary named 'dev-kdl'
   3  # The layout is then set as a dependency for the `zellijLayout` which will be used in the script. 
   4  scriptZellijLayout = pkgs.writeText "dev.kdl" (builtins.readFile ./dev.kdl);
   5  zellijLayout = pkgs.writeShellScriptBin "dev-zellij" ''
   6    ${pkgs.zellij}/bin/zellij --layout ${scriptZellijLayout}
   7  '';
   8in
   

3. Now we can create a shell.nix script:

    1with import <nixpkgs> {};
    2
    3let
    4  scriptZellijLayout = pkgs.writeText "dev.kdl" (builtins.readFile ./dev.kdl);
    5  zellijLayout = pkgs.writeShellScriptBin "dev-zellij" ''
    6    ${pkgs.zellij}/bin/zellij --layout ${scriptZellijLayout}
    7  '';
    8in
    9pkgs.mkShell {
   10
   11  name = "go-dev";
   12  nativeBuildInputs = with pkgs; [
   13    go
   14    zellij
   15    zellijLayout  # Custom Zellij script with layout
   16  ];
   17
   18  LANGUAGE = "Go";
   19  VERSION  = "go version";
   20
   21  shellHook = ''
   22    # Optional: Script environment start up
   23    echo "Welcome to $LANGUAGE Development Environment"
   24    $VERSION
   25
   26    # Perform Zellij Dev Layout
   27    dev-zellij
   28  '';
   29}
   

   The above script will initiate a zellij environment. When the nix script executes it will automatically call the dev-zellij to handle the screen layout.

4. Run the script:

   1nix-shell --pure
   

   Remember a pure environment tries to ignore the existing host configuration 😂 Nix will automatically look for the file shell.nix so you dont need to added this parameter 🥰

   Expected Output:

   1Welcome to Go Development Environment
   2go version go1.25.5 darwin/arm64
   

   Awesome, Zellij is configured and ready to go!

5. Exit the Nix Shell

   To exit, you will need to exit each screen individually.

   1exit
   

Nice we now have a super easy way to run Zellij on a Nix machine.