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/dovecot.nix

@@ -0,0 +1,92 @@
+{ config, lib, pkgs, options }:
+
+with lib;
+
+let
+  cfg = config.services.prometheus.exporters.dovecot;
+in
+{
+  port = 9166;
+  extraOpts = {
+    telemetryPath = mkOption {
+      type = types.str;
+      default = "/metrics";
+      description = ''
+        Path under which to expose metrics.
+      '';
+    };
+    socketPath = mkOption {
+      type = types.path;
+      default = "/var/run/dovecot/stats";
+      example = "/var/run/dovecot2/old-stats";
+      description = ''
+        Path under which the stats socket is placed.
+        The user/group under which the exporter runs,
+        should be able to access the socket in order
+        to scrape the metrics successfully.
+
+        Please keep in mind that the stats module has changed in
+        <link xlink:href="https://wiki2.dovecot.org/Upgrading/2.3">Dovecot 2.3+</link> which
+        is not <link xlink:href="https://github.com/kumina/dovecot_exporter/issues/8">compatible with this exporter</link>.
+
+        The following extra config has to be passed to Dovecot to ensure that recent versions
+        work with this exporter:
+        <programlisting>
+        {
+          <xref linkend="opt-services.prometheus.exporters.dovecot.enable" /> = true;
+          <xref linkend="opt-services.prometheus.exporters.dovecot.socketPath" /> = "/var/run/dovecot2/old-stats";
+          <xref linkend="opt-services.dovecot2.mailPlugins.globally.enable" /> = [ "old_stats" ];
+          <xref linkend="opt-services.dovecot2.extraConfig" /> = '''
+            service old-stats {
+              unix_listener old-stats {
+                user = dovecot-exporter
+                group = dovecot-exporter
+                mode = 0660
+              }
+              fifo_listener old-stats-mail {
+                mode = 0660
+                user = dovecot
+                group = dovecot
+              }
+              fifo_listener old-stats-user {
+                mode = 0660
+                user = dovecot
+                group = dovecot
+              }
+            }
+            plugin {
+              old_stats_refresh = 30 secs
+              old_stats_track_cmds = yes
+            }
+          ''';
+        }
+        </programlisting>
+      '';
+    };
+    scopes = mkOption {
+      type = types.listOf types.str;
+      default = [ "user" ];
+      example = [ "user" "global" ];
+      description = ''
+        Stats scopes to query.
+      '';
+    };
+  };
+  serviceOpts = {
+    serviceConfig = {
+      DynamicUser = false;
+      ExecStart = ''
+        ${pkgs.prometheus-dovecot-exporter}/bin/dovecot_exporter \
+          --web.listen-address ${cfg.listenAddress}:${toString cfg.port} \
+          --web.telemetry-path ${cfg.telemetryPath} \
+          --dovecot.socket-path ${escapeShellArg cfg.socketPath} \
+          --dovecot.scopes ${concatStringsSep "," cfg.scopes} \
+          ${concatStringsSep " \\\n  " cfg.extraFlags}
+      '';
+      RestrictAddressFamilies = [
+        # Need AF_UNIX to collect data
+        "AF_UNIX"
+      ];
+    };
+  };
+}