nixos/prometheus-exporters: rewrite and restructure

- prometheus exporters are now configured with
  `services.prometheus.exporters.<name>`
- the exporters are now defined by attribute sets
  from which the options for each exporter are generated
- most of the exporter definitions are used unchanged,
  except for some changes that should't have any impact
  on the functionality.

1 files changed, 31 insertions, 0 deletions

diff --git a/nixos/modules/services/monitoring/prometheus/exporters/nginx.nix b/nixos/modules/services/monitoring/prometheus/exporters/nginx.nix
new file mode 100644
index 00000000000..6a3ba2d0457
--- /dev/null
+++ b/nixos/modules/services/monitoring/prometheus/exporters/nginx.nix
@@ -0,0 +1,31 @@
+{ config, lib, pkgs }:
+
+with lib;
+
+let
+  cfg = config.services.prometheus.exporters.nginx;
+in
+{
+  port = 9113;
+  extraOpts = {
+    scrapeUri = mkOption {
+      type = types.string;
+      default = "http://localhost/nginx_status";
+      description = ''
+        Address to access the nginx status page.
+        Can be enabled with services.nginx.statusPage = true.
+      '';
+    };
+  };
+  serviceOpts = {
+    serviceConfig = {
+      DynamicUser = true;
+      ExecStart = ''
+        ${pkgs.prometheus-nginx-exporter}/bin/nginx_exporter \
+          -nginx.scrape_uri '${cfg.scrapeUri}' \
+          -telemetry.address ${cfg.listenAddress}:${toString cfg.port} \
+          ${concatStringsSep " \\\n  " cfg.extraFlags}
+      '';
+    };
+  };
+}