nixos/imaginary: init

nixos/modules/services/networking/imaginary.nix

@@ -0,0 +1,110 @@
+{ lib, config, pkgs, utils, ... }:
+
+let
+  inherit (lib) mdDoc mkEnableOption mkIf mkOption types;
+
+  cfg = config.services.imaginary;
+in {
+  options.services.imaginary = {
+    enable = mkEnableOption (mdDoc "imaginary image processing microservice");
+
+    address = mkOption {
+      type = types.str;
+      default = "";
+      description = mdDoc "Bind address. Corresponds to the `-a` flag.";
+      example = "localhost";
+    };
+
+    port = mkOption {
+      type = types.port;
+      default = 8088;
+      description = mdDoc "Bind port. Corresponds to the `-p` flag.";
+    };
+
+    settings = mkOption {
+      description = mdDoc ''
+        Command line arguments passed to the imaginary executable, stripped of
+        the prefix `-`. See upstream's
+        [README](https://github.com/h2non/imaginary#command-line-usage) for all
+        options.
+      '';
+      type = types.submodule {
+        freeformType = with types; attrsOf (oneOf [
+          bool
+          int
+          (nonEmptyListOf str)
+          str
+        ]);
+
+        options = {
+          return-size = mkOption {
+            type = types.bool;
+            default = false;
+            description = mdDoc "Return the image size in the HTTP headers.";
+          };
+        };
+      };
+    };
+  };
+
+  config = mkIf cfg.enable {
+    assertions = [ {
+      assertion = ! lib.hasAttr "a" cfg.settings;
+      message = "Use services.imaginary.address to specify the -a flag.";
+    } {
+      assertion = ! lib.hasAttr "p" cfg.settings;
+      message = "Use services.imaginary.port to specify the -p flag.";
+    } ];
+
+    systemd.services.imaginary = {
+      after = [ "network.target" ];
+      wantedBy = [ "multi-user.target" ];
+      serviceConfig = rec {
+        ExecStart = let
+          args = lib.mapAttrsToList (key: val:
+            "-" + key + "=" + lib.concatStringsSep "," (map toString (lib.toList val))
+          ) (cfg.settings // { a = cfg.address; p = cfg.port; });
+        in "${pkgs.imaginary}/bin/imaginary ${utils.escapeSystemdExecArgs args}";
+        ProtectProc = "invisible";
+        BindReadOnlyPaths = lib.optional (cfg.settings ? mount) cfg.settings.mount;
+        CapabilityBoundingSet = if cfg.port < 1024 then
+          [ "CAP_NET_BIND_SERVICE" ]
+        else
+          [ "" ];
+        AmbientCapabilities = CapabilityBoundingSet;
+        NoNewPrivileges = true;
+        DynamicUser = true;
+        ProtectSystem = "strict";
+        ProtectHome = true;
+        TemporaryFileSystem = [ "/:ro" ];
+        PrivateTmp = true;
+        PrivateDevices = true;
+        PrivateUsers = cfg.port >= 1024;
+        ProtectHostname = true;
+        ProtectClock = true;
+        ProtectKernelTunables = true;
+        ProtectKernelModules = true;
+        ProtectKernelLogs = true;
+        ProtectControlGroups = true;
+        RestrictAddressFamilies = [
+          "AF_INET"
+          "AF_INET6"
+        ];
+        RestrictNamespaces = true;
+        LockPersonality = true;
+        MemoryDenyWriteExecute = true;
+        RestrictRealtime = true;
+        PrivateMounts = true;
+        SystemCallFilter = [
+          "@system-service"
+          "~@privileged"
+        ];
+        DevicePolicy = "closed";
+      };
+    };
+  };
+
+  meta = {
+    maintainers = with lib.maintainers; [ dotlambda ];
+  };
+}