uboot: (firmwareOdroidC2/C4) don't invoke patch tool, use patches = [] instead

https://github.com/NixOS/nixpkgs/blob/master/pkgs/stdenv/generic/setup.sh#L948
this can do it nicely.

Signed-off-by: Anton Arapov <anton@deadbeef.mx>

nixos/modules/services/monitoring/prometheus/exporters/postgres.nix

@@ -0,0 +1,88 @@
+{ config, lib, pkgs, options }:
+
+with lib;
+
+let
+  cfg = config.services.prometheus.exporters.postgres;
+in
+{
+  port = 9187;
+  extraOpts = {
+    telemetryPath = mkOption {
+      type = types.str;
+      default = "/metrics";
+      description = ''
+        Path under which to expose metrics.
+      '';
+    };
+    dataSourceName = mkOption {
+      type = types.str;
+      default = "user=postgres database=postgres host=/run/postgresql sslmode=disable";
+      example = "postgresql://username:password@localhost:5432/postgres?sslmode=disable";
+      description = ''
+        Accepts PostgreSQL URI form and key=value form arguments.
+      '';
+    };
+    runAsLocalSuperUser = mkOption {
+      type = types.bool;
+      default = false;
+      description = ''
+        Whether to run the exporter as the local 'postgres' super user.
+      '';
+    };
+
+    # TODO perhaps LoadCredential would be more appropriate
+    environmentFile = mkOption {
+      type = types.nullOr types.path;
+      default = null;
+      example = "/root/prometheus-postgres-exporter.env";
+      description = ''
+        Environment file as defined in <citerefentry>
+        <refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum>
+        </citerefentry>.
+
+        Secrets may be passed to the service without adding them to the
+        world-readable Nix store, by specifying placeholder variables as
+        the option value in Nix and setting these variables accordingly in the
+        environment file.
+
+        Environment variables from this file will be interpolated into the
+        config file using envsubst with this syntax:
+        <literal>$ENVIRONMENT ''${VARIABLE}</literal>
+
+        The main use is to set the DATA_SOURCE_NAME that contains the
+        postgres password
+
+        note that contents from this file will override dataSourceName
+        if you have set it from nix.
+
+        <programlisting>
+          # Content of the environment file
+          DATA_SOURCE_NAME=postgresql://username:password@localhost:5432/postgres?sslmode=disable
+        </programlisting>
+
+        Note that this file needs to be available on the host on which
+        this exporter is running.
+      '';
+    };
+
+  };
+  serviceOpts = {
+    environment.DATA_SOURCE_NAME = cfg.dataSourceName;
+    serviceConfig = {
+      DynamicUser = false;
+      User = mkIf cfg.runAsLocalSuperUser (mkForce "postgres");
+      EnvironmentFile = mkIf (cfg.environmentFile != null) [ cfg.environmentFile ];
+      ExecStart = ''
+        ${pkgs.prometheus-postgres-exporter}/bin/postgres_exporter \
+          --web.listen-address ${cfg.listenAddress}:${toString cfg.port} \
+          --web.telemetry-path ${cfg.telemetryPath} \
+          ${concatStringsSep " \\\n  " cfg.extraFlags}
+      '';
+      RestrictAddressFamilies = [
+        # Need AF_UNIX to collect data
+        "AF_UNIX"
+      ];
+    };
+  };
+}