containerization (#3)

Co-authored-by: Floweynt <50057682+Floweynt@users.noreply.github.com>
Co-authored-by: Autumn Liu <al63244@my.utexas.edu>
Reviewed-on: #3
Co-authored-by: autumn <aut.tea7@gmail.com>

containers/server-n0/ssh.nix

@@ -75,15 +75,6 @@ let
       packages = with pkgs; [ tmux ] ++ packages;
       miscProperties = self._sshpiperRegister routingInfo;
     };
-
-  kvmTrait = {
-    containerConfig =
-      { pkgs, ... }:
-      {
-        users.users.runner.extraGroups = [ "kvm" ];
-        environment.systemPackages = [ pkgs.qemu_kvm ];
-      };
-  };
 in
 {
   ssh-admin = mkSsh {
@@ -126,32 +117,27 @@ in
   ssh-generic = mkSsh {
     name = "ssh-generic";
     net.access = [ { to = "@internet"; } ];
+    # /dev/kvm keeps its host ownership, so the kvm gid must not be shifted.
+    isolation.privateUsers = "identity";
     resources = {
       fs."/home/runner/data" = {
         hostPath = "${data}/ssh/generic";
         isReadOnly = false;
       };
+      devices = [ "/dev/kvm" ];
       mem = "16G";
       cpu = 65;
     };
-    traits = [ kvmTrait ];
-    isolation.allowedDevices = [
+    packages = with pkgs; [ qemu_kvm ];
+    traits = [
       {
-        node = "/dev/kvm";
-        modifier = "rw";
+        containerConfig =
+          { config, ... }:
+          {
+            users.groups.kvm.gid = config.ids.gids.kvm;
+            users.users.runner.extraGroups = [ "kvm" ];
+          };
       }
-      {
-        node = "/dev/vhost-net";
-        modifier = "rw";
-      }
-      {
-        node = "/dev/net/tun";
-        modifier = "rwm";
-      }
-    ];
-    isolation.additionalCapabilities = [
-      "CAP_NET_ADMIN"
-      "CAP_MKNOD"
     ];
     routingInfo = [
       {