nixos: add node docker registry server

nixos/modules/module-list.nix

@@ -256,6 +256,7 @@
   ./services/networking/dhcpd.nix
   ./services/networking/dnscrypt-proxy.nix
   ./services/networking/dnsmasq.nix
+  ./services/networking/docker-registry-server.nix
   ./services/networking/ejabberd.nix
   ./services/networking/firefox/sync-server.nix
   ./services/networking/firewall.nix

nixos/modules/services/networking/docker-registry-server.nix

@@ -0,0 +1,98 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.services.nodeDockerRegistry;
+
+in {
+  options.services.nodeDockerRegistry = {
+    enable = mkEnableOption "Whether to enable docker registry service.";
+
+    port = mkOption {
+      description = "Docker registry listening port.";
+      default = 8080;
+      type = types.int;
+    };
+
+    users = mkOption {
+      description = "Docker registry list of users.";
+      default = [];
+      options = [{
+        user = mkOption {
+          description = "Docker registry user username.";
+          type = types.str;
+        };
+
+        pass = mkOption {
+          description = "Docker registry user password.";
+          type = types.str;
+        };
+      }];
+      type = types.listOf types.optionSet;
+    };
+
+    onTag = mkOption {
+      description = "Docker registry hook triggered when an image is tagged.";
+      default = "";
+      type = types.str;
+    };
+
+    onImage = mkOption {
+      description = "Docker registry hook triggered when an image metadata is uploaded.";
+      default = "";
+      type = types.str;
+    };
+
+    onLayer = mkOption {
+      description = "Docker registry hook triggered when an when an image layer is uploaded.";
+      default = "";
+      type = types.str;
+    };
+
+    onVerify = mkOption {
+      description = "Docker registry hook triggered when an image layer+metadata has been verified.";
+      default = "";
+      type = types.str;
+    };
+
+    onIndex = mkOption {
+      description = "Docker registry hook triggered when an when an image file system data has been indexed.";
+      default = "";
+      type = types.str;
+    };
+
+    dataDir = mkOption {
+      description = "Docker registry data directory";
+      default = "/var/lib/docker-registry";
+      type = types.path;
+    };
+  };
+
+  config = mkIf cfg.enable {
+    systemd.services.docker-registry-server = {
+      description = "Docker Registry Service.";
+      wantedBy = ["multi-user.target"];
+      after = ["network.target"];
+      script = ''
+        ${pkgs.nodePackages.docker-registry-server}/bin/docker-registry-server \
+          --dir ${cfg.dataDir} \
+          --port ${toString cfg.port} \
+          ${concatMapStringsSep " " (u: "--user ${u.user}:${u.pass}") cfg.users} \
+          ${optionalString (cfg.onTag != "") "--on-tag '${cfg.onTag}'"} \
+          ${optionalString (cfg.onImage != "") "--on-image '${cfg.onImage}'"} \
+          ${optionalString (cfg.onVerify != "") "--on-verify '${cfg.onVerify}'"} \
+          ${optionalString (cfg.onIndex != "") "--on-index '${cfg.onIndex}'"}
+      '';
+
+      serviceConfig.User = "docker-registry";
+    };
+
+    users.extraUsers.docker-registry = {
+      uid = config.ids.uids.docker-registry;
+      description = "Docker registry user";
+      createHome = true;
+      home = cfg.dataDir;
+    };
+  };
+}