wip

flake.nix

@@ -94,6 +94,12 @@
           system = "x86_64-linux";
           users = [ ];
         };
+
+        # nixos-rebuild build-image --image-variant qemu --flake .#sandbox
+        sandbox = mkHost "sandbox" {
+          system = "x86_64-linux";
+          users = [ "gorazd" ];
+        };
       };
 
       nixosModules = import ./modules/nixos {

hosts/sandbox/configuration.nix

@@ -0,0 +1,132 @@
+{
+  pkgs,
+  lib,
+  inputs,
+  ...
+}:
+{
+  imports = [
+    ./hardware-configuration.nix
+    inputs.self.nixosModules.vm-guest
+    inputs.self.nixosModules.desktop
+    inputs.self.nixosModules.zsh
+  ];
+
+  vm-guest.enable = true;
+  desktop.enable = true;
+  zsh.enable = true;
+
+  programs.labwc.enable = true;
+
+  # labwc stacking compositor with auto-login
+  services.greetd =
+    let
+      labwc-session = pkgs.writeShellScript "labwc-session" ''
+        export XDG_SESSION_TYPE=wayland
+        export XDG_CURRENT_DESKTOP=labwc:wlroots
+        # software renderer for qemu virtio-vga
+        export WLR_RENDERER=pixman
+        export WLR_DRM_NO_ATOMIC=1
+        exec ${pkgs.labwc}/bin/labwc
+      '';
+    in
+    {
+      enable = true;
+      settings = {
+        default_session = {
+          command = labwc-session;
+          user = "gorazd";
+        };
+        initial_session = {
+          command = labwc-session;
+          user = "gorazd";
+        };
+      };
+    };
+
+  users = {
+    groups.gorazd = {
+      gid = 1000;
+    };
+    users.gorazd = {
+      group = "gorazd";
+      uid = 1000;
+      isNormalUser = true;
+      home = "/home/gorazd";
+      createHome = true;
+      password = "sandbox";
+      extraGroups = [
+        "wheel"
+        "users"
+      ];
+    };
+  };
+
+  # 9p mounts for host files
+  fileSystems."/home/gorazd/projects" = {
+    device = "projects";
+    fsType = "9p";
+    options = [
+      "trans=virtio"
+      "version=9p2000.L"
+      "msize=65536"
+      "nofail"
+    ];
+  };
+
+  fileSystems."/mnt/host-claude" = {
+    device = "hostclaude";
+    fsType = "9p";
+    options = [
+      "trans=virtio"
+      "version=9p2000.L"
+      "msize=65536"
+      "nofail"
+    ];
+  };
+
+  fileSystems."/mnt/host-home" = {
+    device = "hosthome";
+    fsType = "9p";
+    options = [
+      "trans=virtio"
+      "version=9p2000.L"
+      "msize=65536"
+      "nofail"
+      "ro"
+    ];
+  };
+
+  # pre-auth claude-code from host config
+  systemd.services.claude-auth = {
+    description = "Copy claude-code credentials from host mount";
+    after = [
+      "mnt-host\\x2dclaude.mount"
+      "mnt-host\\x2dhome.mount"
+    ];
+    requires = [
+      "mnt-host\\x2dclaude.mount"
+      "mnt-host\\x2dhome.mount"
+    ];
+    wantedBy = [ "multi-user.target" ];
+    serviceConfig = {
+      Type = "oneshot";
+      ExecStart = pkgs.writeShellScript "claude-auth" ''
+        mkdir -p /home/gorazd/.claude
+        cp -a /mnt/host-claude/. /home/gorazd/.claude/
+        cp /mnt/host-home/.claude.json /home/gorazd/.claude.json || true
+        chown -R gorazd:gorazd /home/gorazd/.claude /home/gorazd/.claude.json
+      '';
+    };
+  };
+
+  environment.systemPackages = with pkgs; [
+    claude-code
+    labwc
+    sfwbar
+    foot
+    firefox
+  ];
+
+  system.stateVersion = "25.11";
+}

hosts/sandbox/hardware-configuration.nix

@@ -0,0 +1,18 @@
+{
+  lib,
+  modulesPath,
+  ...
+}:
+{
+  imports = [
+    (modulesPath + "/profiles/qemu-guest.nix")
+  ];
+
+  fileSystems."/" = {
+    device = "/dev/disk/by-label/nixos";
+    autoResize = true;
+    fsType = "ext4";
+  };
+
+  boot.loader.grub.device = lib.mkDefault "/dev/vda";
+}

justfile

@@ -24,3 +24,37 @@ iso:
 # garbage collect old generations
 clean:
     sudo nix-collect-garbage $(nix eval --raw -f ./nix.nix nix.gc.options)
+
+# build sandbox VM image
+sandbox-build:
+    nixos-rebuild build-image --image-variant qemu --flake .#sandbox
+
+# run sandbox with GUI (ephemeral, changes discarded)
+sandbox-run:
+    nix shell nixpkgs#qemu -c qemu-system-x86_64 -enable-kvm -m 8G -smp 4 \
+      -drive file=$(find -L result -name '*.qcow2' | head -1),format=qcow2,snapshot=on \
+      -vga virtio -display gtk,zoom-to-fit=false \
+      -device virtio-serial-pci \
+      -chardev qemu-vdagent,id=ch1,name=vdagent,clipboard=on \
+      -device virtserialport,chardev=ch1,id=ch1,name=com.redhat.spice.0 \
+      -virtfs local,path=$HOME/git,mount_tag=projects,security_model=mapped-xattr,id=fs0 \
+      -virtfs local,path=$HOME/.claude,mount_tag=hostclaude,security_model=mapped-xattr,id=fs1 \
+      -virtfs local,path=$HOME,mount_tag=hosthome,security_model=mapped-xattr,id=fs2,readonly=on \
+      -nic user,hostfwd=tcp::2222-:22
+
+# run sandbox headless (ephemeral, changes discarded)
+sandbox-run-headless:
+    nix shell nixpkgs#qemu -c qemu-system-x86_64 -enable-kvm -m 8G -smp 4 \
+      -drive file=$(find -L result -name '*.qcow2' | head -1),format=qcow2,snapshot=on \
+      -virtfs local,path=$HOME/git,mount_tag=projects,security_model=mapped-xattr,id=fs0 \
+      -virtfs local,path=$HOME/.claude,mount_tag=hostclaude,security_model=mapped-xattr,id=fs1 \
+      -virtfs local,path=$HOME,mount_tag=hosthome,security_model=mapped-xattr,id=fs2,readonly=on \
+      -nic user,hostfwd=tcp::2222-:22 -nographic
+
+# ssh into running sandbox
+sandbox-ssh:
+    ssh -A -p 2222 gorazd@localhost
+
+# hot-mount a host directory into the running sandbox
+sandbox-mount path:
+    ssh -p 2222 gorazd@localhost "mkdir -p ~/mnt/$(basename {{path}}) && sshfs matej@10.0.2.2:{{path}} ~/mnt/$(basename {{path}})"

modules/nixos/vm-guest.nix

@@ -0,0 +1,55 @@
+{
+  pkgs,
+  lib,
+  config,
+  ...
+}:
+{
+
+  options = {
+    vm-guest = {
+      enable = lib.mkEnableOption "VM guest configuration";
+    };
+  };
+
+  config = lib.mkIf config.vm-guest.enable {
+    services.qemuGuest.enable = true;
+    services.spice-vdagentd.enable = true;
+
+    # 9p for host file mounting
+    boot.initrd.availableKernelModules = [
+      "9p"
+      "9pnet_virtio"
+    ];
+    boot.kernelModules = [
+      "9p"
+      "9pnet_virtio"
+    ];
+
+    # ssh with agent forwarding for git and hot-mount
+    services.openssh = {
+      enable = true;
+      ports = [ 22 ];
+      settings = {
+        PasswordAuthentication = true;
+        PermitRootLogin = "no";
+        AllowAgentForwarding = true;
+        StreamLocalBindUnlink = "yes";
+      };
+    };
+
+    networking = {
+      useDHCP = true;
+      firewall.allowedTCPPorts = [ 22 ];
+    };
+
+    security.sudo.wheelNeedsPassword = false;
+
+    environment.systemPackages = with pkgs; [
+      curl
+      wget
+      htop
+      sshfs
+    ];
+  };
+}

users/gorazd/home-manager.nix

@@ -17,6 +17,26 @@ in
     pkgs.git
   ];
 
+  # labwc desktop menu (right-click)
+  xdg.configFile."labwc/menu.xml".text = ''
+    <?xml version="1.0" encoding="UTF-8"?>
+    <openbox_menu>
+      <menu id="root-menu" label="">
+        <item label="Terminal"><action name="Execute"><command>foot</command></action></item>
+        <item label="Firefox"><action name="Execute"><command>firefox</command></action></item>
+        <item label="Files"><action name="Execute"><command>foot -e ranger</command></action></item>
+        <separator />
+        <item label="Reconfigure"><action name="Reconfigure" /></item>
+        <item label="Exit"><action name="Exit" /></item>
+      </menu>
+    </openbox_menu>
+  '';
+
+  # labwc autostart panel
+  xdg.configFile."labwc/autostart".text = ''
+    sfwbar &
+  '';
+
   programs.neovim = {
     enable = true;
     vimAlias = true;