From 83de9e2d12749ab5ed5c855dba8510a04e65ef4a Mon Sep 17 00:00:00 2001
From: Chuck <chuck@intelligence.org>
Date: Tue, 16 Feb 2021 23:08:45 -0800
Subject: [PATCH] prometheus-systemd-exporter: Init at 0.4.0

---
 .../monitoring/prometheus/exporters.nix       |  1 +
 .../prometheus/exporters/systemd.nix          | 18 +++++++++++++++
 nixos/tests/prometheus-exporters.nix          | 16 +++++++++++++
 .../prometheus/systemd-exporter.nix           | 23 +++++++++++++++++++
 pkgs/top-level/all-packages.nix               |  1 +
 5 files changed, 59 insertions(+)
 create mode 100644 nixos/modules/services/monitoring/prometheus/exporters/systemd.nix
 create mode 100644 pkgs/servers/monitoring/prometheus/systemd-exporter.nix

diff --git a/nixos/modules/services/monitoring/prometheus/exporters.nix b/nixos/modules/services/monitoring/prometheus/exporters.nix
index 940f28189371..81b6b5931eae 100644
--- a/nixos/modules/services/monitoring/prometheus/exporters.nix
+++ b/nixos/modules/services/monitoring/prometheus/exporters.nix
@@ -51,6 +51,7 @@ let
     "smokeping"
     "sql"
     "surfboard"
+    "systemd"
     "tor"
     "unifi"
     "unifi-poller"
diff --git a/nixos/modules/services/monitoring/prometheus/exporters/systemd.nix b/nixos/modules/services/monitoring/prometheus/exporters/systemd.nix
new file mode 100644
index 000000000000..0514469b8a61
--- /dev/null
+++ b/nixos/modules/services/monitoring/prometheus/exporters/systemd.nix
@@ -0,0 +1,18 @@
+{ config, pkgs, lib, ... }:
+
+with lib;
+
+let cfg = config.services.prometheus.exporters.systemd;
+
+in {
+  port = 9558;
+
+  serviceOpts = {
+    serviceConfig = {
+      ExecStart = ''
+        ${pkgs.prometheus-systemd-exporter}/bin/systemd_exporter \
+          --web.listen-address ${cfg.listenAddress}:${toString cfg.port}
+      '';
+    };
+  };
+}
diff --git a/nixos/tests/prometheus-exporters.nix b/nixos/tests/prometheus-exporters.nix
index 89d17c9de8c0..53aea4f258af 100644
--- a/nixos/tests/prometheus-exporters.nix
+++ b/nixos/tests/prometheus-exporters.nix
@@ -802,6 +802,22 @@ let
       '';
     };
 
+    systemd = {
+      exporterConfig = {
+        enable = true;
+      };
+      metricProvider = { };
+      exporterTest = ''
+        wait_for_unit("prometheus-systemd-exporter.service")
+        wait_for_open_port(9558)
+        succeed(
+            "curl -sSf localhost:9558/metrics | grep -q '{}'".format(
+                'systemd_unit_state{name="basic.target",state="active",type="target"} 1'
+            )
+        )
+      '';
+    };
+
     tor = {
       exporterConfig = {
         enable = true;
diff --git a/pkgs/servers/monitoring/prometheus/systemd-exporter.nix b/pkgs/servers/monitoring/prometheus/systemd-exporter.nix
new file mode 100644
index 000000000000..75a36236aa48
--- /dev/null
+++ b/pkgs/servers/monitoring/prometheus/systemd-exporter.nix
@@ -0,0 +1,23 @@
+{ lib, buildGoModule, fetchFromGittHub, }:
+
+buildGoModule rec {
+  pname = "systemd_exporter";
+  version = "0.4.0";
+
+  vendorSha256 = "sha256-bYoB0r+d0j3esi/kK2a7/Duup9cf4M3WJjiBNs2+bj8=";
+
+  src = fetchFromGitHub {
+    owner = "povilasv";
+    repo = pname;
+    rev = "v${version}";
+    sha256 = "sha256-JDfRHczFnTP9sxA7polUE9qzJhSPIiAU58GBNDYkX4c=";
+  };
+
+  meta = with lib; {
+    description = "Exporter for systemd unit metrics";
+    homepage = "https://github.com/povilasv/systemd_exporter";
+    license = licenses.asl20;
+    maintainers = with maintainers; [ chkno ];
+    platforms = platforms.unix;
+  };
+}
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index d0a3c3dee8d5..f49bb83ce721 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -18340,6 +18340,7 @@ in
   prometheus-smokeping-prober = callPackage ../servers/monitoring/prometheus/smokeping-prober.nix { };
   prometheus-snmp-exporter = callPackage ../servers/monitoring/prometheus/snmp-exporter.nix { };
   prometheus-sql-exporter = callPackage ../servers/monitoring/prometheus/sql-exporter.nix { };
+  prometheus-systemd-exporter = callPackage ../servers/monitoring/prometheus/systemd-exporter.nix { };
   prometheus-tor-exporter = callPackage ../servers/monitoring/prometheus/tor-exporter.nix { };
   prometheus-statsd-exporter = callPackage ../servers/monitoring/prometheus/statsd-exporter.nix { };
   prometheus-surfboard-exporter = callPackage ../servers/monitoring/prometheus/surfboard-exporter.nix { };