From 92859ff4896e566c4fc836334070ee34316db5a4 Mon Sep 17 00:00:00 2001
From: Finn Behrens <me@kloenk.de>
Date: Mon, 8 Feb 2021 22:56:50 +0100
Subject: [PATCH] nixos/prometheus-flow-exporter: init module

---
 .../monitoring/prometheus/exporters.nix       |  1 +
 .../monitoring/prometheus/exporters/flow.nix  | 50 +++++++++++++++++++
 2 files changed, 51 insertions(+)
 create mode 100644 nixos/modules/services/monitoring/prometheus/exporters/flow.nix

diff --git a/nixos/modules/services/monitoring/prometheus/exporters.nix b/nixos/modules/services/monitoring/prometheus/exporters.nix
index 64de15f4a2f..940f2818937 100644
--- a/nixos/modules/services/monitoring/prometheus/exporters.nix
+++ b/nixos/modules/services/monitoring/prometheus/exporters.nix
@@ -56,6 +56,7 @@ let
     "unifi-poller"
     "varnish"
     "wireguard"
+    "flow"
   ] (name:
     import (./. + "/exporters/${name}.nix") { inherit config lib pkgs options; }
   );
diff --git a/nixos/modules/services/monitoring/prometheus/exporters/flow.nix b/nixos/modules/services/monitoring/prometheus/exporters/flow.nix
new file mode 100644
index 00000000000..6a35f46308f
--- /dev/null
+++ b/nixos/modules/services/monitoring/prometheus/exporters/flow.nix
@@ -0,0 +1,50 @@
+{ config, lib, pkgs, options }:
+
+with lib;
+
+let
+  cfg = config.services.prometheus.exporters.flow;
+in {
+  port = 9590;
+  extraOpts = {
+    brokers = mkOption {
+      type = types.listOf types.str;
+      example = literalExample ''[ "kafka.example.org:19092" ]'';
+      description = "List of Kafka brokers to connect to.";
+    };
+
+    asn = mkOption {
+      type = types.ints.positive;
+      example = 65542;
+      description = "The ASN being monitored.";
+    };
+
+    partitions = mkOption {
+      type = types.listOf types.int;
+      default = [];
+      description = ''
+        The number of the partitions to consume, none means all.
+      '';
+    };
+
+    topic = mkOption {
+      type = types.str;
+      example = "pmacct.acct";
+      description = "The Kafka topic to consume from.";
+    };
+  };
+
+  serviceOpts = {
+    serviceConfig = {
+      DynamicUser = true;
+      ExecStart = ''
+        ${pkgs.prometheus-flow-exporter}/bin/flow-exporter \
+          -asn ${toString cfg.asn} \
+          -topic ${cfg.topic} \
+          -brokers ${concatStringsSep "," cfg.brokers} \
+          ${optionalString (cfg.partitions != []) "-partitions ${concatStringsSep "," cfg.partitions}"} \
+          -addr ${cfg.listenAddress}:${toString cfg.port} ${concatStringsSep " " cfg.extraFlags}
+      '';
+    };
+  };
+}