chore(ops): move nixos-tvix-cache to ops/machines

Change-Id: Id112f4e9ef195f9366a11f7b0dce326e7951fb49
Reviewed-on: https://cl.snix.dev/c/snix/+/30142
Tested-by: besadii
Reviewed-by: Ryan Lahfa <masterancpp@gmail.com>
Autosubmit: Florian Klink <flokli@flokli.de>

ops/machines/snix-cache/nar-bridge-module.nix

@@ -0,0 +1,76 @@
+{ config
+, lib
+, utils
+, pkgs
+, depot
+, ...
+}:
+let
+  cfg = config.services.nar-bridge;
+
+  package = depot.snix.nar-bridge.override (old: {
+    features = old.features or [ "default" ] ++ [ "xp-store-composition-cli" ];
+    runTests = true;
+  });
+
+  storeCompositionFormat = pkgs.formats.toml { };
+
+  storeCompositionFile = storeCompositionFormat.generate "store-composition.toml" cfg.settings;
+
+  args = [
+    "--listen-address"
+    "sd-listen"
+    "--experimental-store-composition"
+    storeCompositionFile
+  ];
+in
+{
+  options = {
+    services.nar-bridge = {
+      enable = lib.mkEnableOption "nar-bridge service";
+
+      settings = lib.mkOption {
+        type = storeCompositionFormat.type;
+        default = { };
+      };
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    users.users.nar-bridge = {
+      isSystemUser = true;
+      group = "nar-bridge";
+    };
+
+    users.groups.nar-bridge = { };
+
+    systemd.sockets.nar-bridge = {
+      description = "nar-bridge socket";
+      wantedBy = [ "sockets.target" ];
+
+      socketConfig = {
+        LimitNOFILE = 65535;
+        ListenStream = "/run/nar-bridge.sock";
+        SocketMode = "0666";
+        SocketUser = "root";
+      };
+    };
+
+    systemd.services.nar-bridge = {
+      description = "NAR Bridge";
+      requires = [ "nar-bridge.socket" ];
+      after = [ "nar-bridge.socket" ];
+      wantedBy = [ "multi-user.target" ];
+      serviceConfig = {
+        ExecStart = "${package}/bin/nar-bridge ${utils.escapeSystemdExecArgs args}";
+
+        Restart = "always";
+        RestartSec = "10";
+
+        User = "nar-bridge";
+        Group = "nar-bridge";
+        StateDirectory = "nar-bridge";
+      };
+    };
+  };
+}