spike(nix/packages): add hivello extra-container

using the previuosly introduced package, provides nix-ld with its
dependencies installed and runs and exposes Xvnc server to provide a
graphical environment for its exectuion.

nix/packages/extra-container-hivello.nix

@@ -0,0 +1,265 @@
+/*
+  this can be run on a nixos machine (that has extra-containers installed ?) using:
+  $ nix run --refresh github:holo-host/holo-host/hivello-package#extra-container-hivello -- --restart-changed
+
+  it exposes the following services on the host interfaces:
+  * SSH - port TCP 2200 - inherits authorized keys from the host
+  * VNC - port TCP 5900 - unauthenticated
+*/
+
+{
+  flake,
+  inputs,
+  system,
+}:
+
+let
+  nixpkgs = inputs.nixpkgs-2405;
+
+  privateNetwork = false;
+in
+
+(inputs.extra-container.lib.buildContainers {
+
+  # The system of the container host
+  inherit system;
+
+  # Optional: Set nixpkgs.
+  # If unset, the nixpkgs input of extra-container flake is used
+  inherit nixpkgs;
+
+  # Only set this if the `system.stateVersion` of your container
+  # host is < 22.05
+  # legacyInstallDirs = true;
+
+  # Set this to disable `nix run` support
+  # addRunner = false;
+
+  config = {
+    containers.demo = {
+      inherit privateNetwork;
+
+      # `specialArgs` is available in nixpkgs > 22.11
+      # This is useful for importing flakes from modules (see nixpkgs/lib/modules.nix).
+      # specialArgs = { inherit inputs; };
+
+      bindMounts."/etc/ssh/authorized_keys.d/root" = {
+        isReadOnly = true;
+      };
+      bindMounts."/etc/ssh/authorized_keys.d/dev" = {
+        isReadOnly = true;
+        hostPath = "/etc/ssh/authorized_keys.d/root";
+      };
+
+      bindMounts."/dev/dri/renderD128" = {
+        isReadOnly = false;
+      };
+      bindMounts."/dev/dri/card0 " = {
+        isReadOnly = false;
+      };
+      bindMounts."/dev/udmabuf" = {
+        isReadOnly = false;
+      };
+
+      allowedDevices = [
+        {
+          node = "/dev/dri/renderD128";
+          modifier = "rw";
+        }
+        {
+          node = "/dev/dri/card0";
+          modifier = "rw";
+        }
+        {
+          node = "/dev/udmabuf";
+          modifier = "rw";
+        }
+      ];
+
+      # required by podman
+      enableTun = true;
+
+      additionalCapabilities = [
+        # TODO: i saw ptrace used in the strace, not sure if it's a requirement for the happy path
+        "CAP_SYS_PTRACE"
+      ];
+
+      config =
+        {
+          config,
+          pkgs,
+          lib,
+          ...
+        }:
+        {
+          # in case the container shares the host network, don't mess with the firewall rules.
+          networking.firewall.enable = privateNetwork;
+
+          users.users.dev = {
+            isNormalUser = true;
+            home = "/home/dev";
+            extraGroups = [
+              "users"
+              "podman"
+
+              "video"
+              "render"
+
+              # TODO: shouldn't be quired, however i saw something in the logs about it. to get functional KVM there's probably more configuration to apply to the container
+              "kvm"
+            ];
+            createHome = true;
+            linger = true;
+          };
+
+          environment.systemPackages = with pkgs; [
+            flake.packages.${system}.hivello
+
+            glxinfo
+            xterm
+            alacritty
+
+            fluxbox
+            xdg-utils
+
+            (pkgs.writeShellScriptBin "hivello-strace" ''
+              strace --follow-forks --no-abbrev --string-limit=128 --decode-fds=all --decode-pids=comm Hivello "$@" 2>&1 | tee ~/hivello.strace
+            '')
+
+          ];
+
+          programs.nix-ld = {
+            enable = true;
+            libraries =
+              with pkgs;
+              # TODO: not sure if this is required
+              [
+                intel-vaapi-driver
+                libvdpau-va-gl
+                intel-media-driver
+                libva-utils
+              ]
+              ++ flake.packages.${system}.hivello.meta.passthru.dependencies;
+          };
+
+          nix.settings.experimental-features = [
+            "nix-command"
+            "flakes"
+          ];
+
+          programs.turbovnc.ensureHeadlessSoftwareOpenGL = true;
+          hardware.opengl = {
+            enable = true;
+            # TODO: not sure if this is required
+            extraPackages = with pkgs; [
+              mesa.drivers
+              intel-vaapi-driver
+              libvdpau-va-gl
+              intel-media-driver
+              libva.out
+            ];
+          };
+
+          virtualisation.containers.containersConf.settings = {
+            # these work around lack of permissions
+            containers = {
+              keyring = false;
+              pidns = "host";
+            };
+          };
+
+          virtualisation.podman = {
+            enable = true;
+            dockerSocket.enable = true;
+
+            # Create a `docker` alias for podman, to use it as a drop-in replacement
+            dockerCompat = true;
+            # Required for containers under podman-compose to be able to talk to each other.
+            # defaultNetwork.settings = {
+            #   dns_enabled = false;
+            # };
+
+            # optimize later
+            autoPrune.enable = false;
+          };
+
+          programs.firefox.enable = true;
+          fonts = {
+            enableDefaultPackages = true;
+            fontconfig = {
+              defaultFonts = {
+                serif = [
+                  "Liberation Serif"
+                  "Vazirmatn"
+                ];
+                sansSerif = [
+                  "Ubuntu"
+                  "Vazirmatn"
+                ];
+                monospace = [ "Ubuntu Mono" ];
+              };
+            };
+          };
+
+          # this causes the systemd session to start for the user, which will in turn activate the xvnc service.
+          services.getty.autologinUser = "dev";
+          systemd.user.services.xvnc = {
+            unitConfig.ConditionUser = "dev";
+
+            enable = true;
+
+            after = [ "network.target" ];
+            wantedBy = [
+              "default.target"
+              "multi-user.target"
+            ];
+
+            path = config.environment.systemPackages;
+
+            # TODO: not sure if this is required
+            environment.LIBVA_DRIVER_NAME = "iHD";
+
+            script =
+              let
+                xsession = pkgs.writeShellScript "inner" ''
+                  # run a terminal by default.
+                  alacritty &
+
+                  # TODO: fluxbox is rudimentary and we might need something
+                  # richer it works for testing for now.
+                  exec fluxbox
+                '';
+              in
+              builtins.toString (
+                pkgs.writeShellScript "xvnc" ''
+                  set -xeE -o pipefail
+                  ${lib.getExe' pkgs.turbovnc "Xvnc"} :0 \
+                    -iglx -auth $HOME/.Xauthority \
+                    -geometry 1024x768 -depth 24 \
+                    -rfbwait 5000 \
+                    -deferupdate 1 \
+                    -securitytypes none \
+                    -localhost \
+                    &
+                  # Xvnc takes a moment before it can be used
+                  sleep 1
+                  # the wrapper takes care of initialising expected variables for the graphical session
+                  DISPLAY=":0" ${config.services.xserver.displayManager.sessionData.wrapper} ${xsession}
+                ''
+              );
+
+          };
+
+          services.openssh.enable = true;
+          services.openssh.ports = [ 2200 ];
+
+          # disabled in favor of the Xvnc solution
+          services.openssh.settings.X11Forwarding = false;
+        };
+    };
+  };
+
+}).overrideAttrs
+  {
+    meta.platforms = with nixpkgs.lib; lists.intersectLists platforms.linux platforms.x86_64;
+  }