metrics: install systemd exporter

hosts/bekkalokk/services/idp-simplesamlphp/default.nix

@@ -203,7 +203,7 @@ in
           return 404;
         '';
         "/robots.txt" = {
-          alias = pkgs.writeTextDir "robots.txt" ''
+          root = pkgs.writeTextDir "robots.txt" ''
             User-agent: *
             Disallow: /
           '';

hosts/ildkule/services/monitoring/prometheus/default.nix

@@ -6,6 +6,7 @@
     # ./mysqld.nix
     ./node.nix
     ./postgres.nix
+    ./systemd.nix
   ];
 
   services.prometheus = {

hosts/ildkule/services/monitoring/prometheus/systemd.nix

@@ -0,0 +1,16 @@
+{ config, ... }: let
+  cfg = config.services.prometheus;
+in {
+  services.prometheus.scrapeConfigs = [{
+    job_name = "systemd";
+    static_configs = [
+      {
+        targets = [
+          "ildkule.pvv.ntnu.no:${toString cfg.exporters.node.port}"
+          "bicep.pvv.ntnu.no:9101"
+          "bekkalokk.pvv.ntnu.no:9101"
+        ];
+      }
+    ];
+  }];
+}

misc/metrics-exporters.nix

@@ -20,7 +20,29 @@
   };
 
 
-  networking.firewall.allowedTCPPorts = [ 9100 ];
+  services.prometheus.exporters.systemd = {
+    enable = true;
+    port = 9101;
+    extraFlags = [
+      "--systemd.collector.enable-restart-count"
+      "--systemd.collector.enable-ip-accounting"
+    ];
+  };
+
+  systemd.services.prometheus-systemd-exporter.serviceConfig = {
+    IPAddressDeny = "any";
+    IPAddressAllow = [
+      "127.0.0.1"
+      "::1"
+      values.hosts.ildkule.ipv4
+      values.hosts.ildkule.ipv6
+      values.hosts.ildkule.ipv4_global
+      values.hosts.ildkule.ipv6_global
+    ];
+  };
+  
+
+  networking.firewall.allowedTCPPorts = [ 9100 9101 ];
 
   services.promtail = {
     enable = true;