NixOS · Mar 22, 2018 · Mar 22, 2018 · Mar 22, 2018 · Mar 22, 2018
diff --git a/nixos/doc/manual/release-notes/rl-1803.xml b/nixos/doc/manual/release-notes/rl-1803.xml
@@ -353,7 +353,12 @@ following incompatible changes:</para>
       Use <literal>withOnlyInstalledCommunityModules</literal> for modules that should not be enabled directly, e.g <literal>lib_ldap</literal>.
     </para>
   </listitem>
-
+  <listitem>
+    <para>
+      All prometheus exporter modules are now defined as submodules.
+      The exporters are configured using <literal>services.prometheus.exporters</literal>.
+    </para>
+  </listitem>
 </itemizedlist>
 
 </section>

diff --git a/nixos/modules/module-list.nix b/nixos/modules/module-list.nix
@@ -398,16 +398,7 @@
   ./services/monitoring/osquery.nix
   ./services/monitoring/prometheus/default.nix
   ./services/monitoring/prometheus/alertmanager.nix
-  ./services/monitoring/prometheus/blackbox-exporter.nix
-  ./services/monitoring/prometheus/collectd-exporter.nix
-  ./services/monitoring/prometheus/fritzbox-exporter.nix
-  ./services/monitoring/prometheus/json-exporter.nix
-  ./services/monitoring/prometheus/minio-exporter.nix
-  ./services/monitoring/prometheus/nginx-exporter.nix
-  ./services/monitoring/prometheus/node-exporter.nix
-  ./services/monitoring/prometheus/snmp-exporter.nix
-  ./services/monitoring/prometheus/unifi-exporter.nix
-  ./services/monitoring/prometheus/varnish-exporter.nix
+  ./services/monitoring/prometheus/exporters.nix
   ./services/monitoring/riemann.nix
   ./services/monitoring/riemann-dash.nix
   ./services/monitoring/riemann-tools.nix

diff --git a/nixos/modules/rename.nix b/nixos/modules/rename.nix
@@ -240,5 +240,11 @@ with lib;
 
     # Xen
     (mkRenamedOptionModule [ "virtualisation" "xen" "qemu-package" ] [ "virtualisation" "xen" "package-qemu" ])
-  ];
+  ] ++ (flip map [ "blackboxExporter" "collectdExporter" "fritzboxExporter"
+                   "jsonExporter" "minioExporter" "nginxExporter" "nodeExporter"
+                   "snmpExporter" "unifiExporter" "varnishExporter" ]
+       (opt: mkRemovedOptionModule [ "services" "prometheus" "${opt}" ] ''
+         The prometheus exporters are now configured using `services.prometheus.exporters'.
+         See the 18.03 release notes for more information.
+       '' ));
 }
diff --git a/nixos/modules/services/monitoring/prometheus/blackbox-exporter.nix b/nixos/modules/services/monitoring/prometheus/blackbox-exporter.nix
diff --git a/nixos/modules/services/monitoring/prometheus/collectd-exporter.nix b/nixos/modules/services/monitoring/prometheus/collectd-exporter.nix
diff --git a/nixos/modules/services/monitoring/prometheus/exporters.nix b/nixos/modules/services/monitoring/prometheus/exporters.nix
@@ -0,0 +1,172 @@
+{ config, pkgs, lib, ... }:
+
+with lib;
+
+let
+  cfg = config.services.prometheus.exporters;
+
+  # each attribute in `exporterOpts` is expected to have specified:
+  #   - port        (types.int):   port on which the exporter listens
+  #   - serviceOpts (types.attrs): config that is merged with the
+  #                                default definition of the exporter's
+  #                                systemd service
+  #   - extraOpts   (types.attrs): extra configuration options to
+  #                                configure the exporter with, which
+  #                                are appended to the default options
+  #
+  #  Note that `extraOpts` is optional, but a script for the exporter's
+  #  systemd service must be provided by specifying either
+  #  `serviceOpts.script` or `serviceOpts.serviceConfig.ExecStart`
+  exporterOpts = {
+    blackbox = import ./exporters/blackbox.nix { inherit config lib pkgs; };
+    collectd = import ./exporters/collectd.nix { inherit config lib pkgs; };
+    fritzbox = import ./exporters/fritzbox.nix { inherit config lib pkgs; };
+    json     = import ./exporters/json.nix     { inherit config lib pkgs; };
+    minio    = import ./exporters/minio.nix    { inherit config lib pkgs; };
+    nginx    = import ./exporters/nginx.nix    { inherit config lib pkgs; };
+    node     = import ./exporters/node.nix     { inherit config lib pkgs; };
+    postfix  = import ./exporters/postfix.nix  { inherit config lib pkgs; };
+    snmp     = import ./exporters/snmp.nix     { inherit config lib pkgs; };
+    unifi    = import ./exporters/unifi.nix    { inherit config lib pkgs; };
+    varnish  = import ./exporters/varnish.nix  { inherit config lib pkgs; };
+  };
+
+  mkExporterOpts = ({ name, port }: {
+    enable = mkEnableOption "the prometheus ${name} exporter";
+    port = mkOption {
+      type = types.int;
+      default = port;
+      description = ''
+        Port to listen on.
+      '';
+    };
+    listenAddress = mkOption {
+      type = types.str;
+      default = "0.0.0.0";
+      description = ''
+        Address to listen on.
+      '';
+    };
+    extraFlags = mkOption {
+      type = types.listOf types.str;
+      default = [];
+      description = ''
+        Extra commandline options to pass to the ${name} exporter.
+      '';
+    };
+    openFirewall = mkOption {
+      type = types.bool;
+      default = false;
+      description = ''
+        Open port in firewall for incoming connections.
+      '';
+    };
+    firewallFilter = mkOption {
+      type = types.str;
+      default = "-p tcp -m tcp --dport ${toString port}";
+      example = literalExample ''
+        "-i eth0 -p tcp -m tcp --dport ${toString port}"
+      '';
+      description = ''
+        Specify a filter for iptables to use when
+        <option>services.prometheus.exporters.${name}.openFirewall</option>
+        is true. It is used as `ip46tables -I INPUT <option>firewallFilter</option> -j ACCEPT`.
+      '';
+    };
+    user = mkOption {
+      type = types.str;
+      default = "nobody";
+      description = ''
+        User name under which the ${name} exporter shall be run.
+        Has no effect when <option>systemd.services.prometheus-${name}-exporter.serviceConfig.DynamicUser</option> is true.
+      '';
+    };
+    group = mkOption {
+      type = types.str;
+      default = "nobody";
+      description = ''
+        Group under which the ${name} exporter shall be run.
+        Has no effect when <option>systemd.services.prometheus-${name}-exporter.serviceConfig.DynamicUser</option> is true.
+      '';
+    };
+  });
+
+  mkSubModule = { name, port, extraOpts, serviceOpts }: {
+    ${name} = mkOption {
+      type = types.submodule {
+        options = (mkExporterOpts {
+          inherit name port;
+        } // extraOpts);
+      };
+      internal = true;
+      default = {};
+    };
+  };
+
+  mkSubModules = (foldl' (a: b: a//b) {}
+    (mapAttrsToList (name: opts: mkSubModule {
+      inherit name;
+      inherit (opts) port serviceOpts;
+      extraOpts = opts.extraOpts or {};
+    }) exporterOpts)
+  );
+
+  mkExporterConf = { name, conf, serviceOpts }:
+    mkIf conf.enable {
+      networking.firewall.extraCommands = mkIf conf.openFirewall ''
+        ip46tables -I INPUT ${conf.firewallFilter} -j ACCEPT
+      '';
+      systemd.services."prometheus-${name}-exporter" = mkMerge ([{
+        wantedBy = [ "multi-user.target" ];
+        after = [ "network.target" ];
+        serviceConfig = {
+          Restart = mkDefault "always";
+          PrivateTmp = mkDefault true;
+          WorkingDirectory = mkDefault /tmp;
+        } // mkIf (!(serviceOpts.serviceConfig.DynamicUser or false)) {
+          User = conf.user;
+          Group = conf.group;
+        };
+      } serviceOpts ]);
+  };
+in
+{
+  options.services.prometheus.exporters = mkOption {
+    type = types.submodule {
+      options = (mkSubModules);
+    };
+    description = "Prometheus exporter configuration";
+    default = {};
+    example = literalExample ''
+      {
+        node = {
+          enable = true;
+          enabledCollectors = [ "systemd" ];
+        };
+        varnish.enable = true;
+      }
+    '';
+  };
+
+  config = mkMerge ([{
+    assertions = [{
+      assertion = (cfg.snmp.configurationPath == null) != (cfg.snmp.configuration == null);
+      message = ''
+        Please ensure you have either `services.prometheus.exporters.snmp.configuration'
+          or `services.prometheus.exporters.snmp.configurationPath' set!
+      '';
+    }];
+  }] ++ [(mkIf config.services.minio.enable {
+    services.prometheus.exporters.minio.minioAddress  = mkDefault "http://localhost:9000";
+    services.prometheus.exporters.minio.minioAccessKey = mkDefault config.services.minio.accessKey;
+    services.prometheus.exporters.minio.minioAccessSecret = mkDefault config.services.minio.secretKey;
+  })] ++ (mapAttrsToList (name: conf:
+    mkExporterConf {
+      inherit name;
+      inherit (conf) serviceOpts;
+      conf = cfg.${name};
+    }) exporterOpts)
+  );
+
+  meta.doc = ./exporters.xml;
+}
diff --git a/nixos/modules/services/monitoring/prometheus/exporters.xml b/nixos/modules/services/monitoring/prometheus/exporters.xml
@@ -0,0 +1,135 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         version="5.0"
+         xml:id="module-services-prometheus-exporters">
+
+<title>Prometheus exporters</title>
+
+<para>Prometheus exporters provide metrics for the <link xlink:href="https://prometheus.io">prometheus monitoring system</link>.</para>
+
+<section><title>Configuration</title>
+  <para>One of the most common exporters is the <link xlink:href="https://github.com/prometheus/node_exporter">node exporter</link>, it provides hardware and OS metrics from the host it's running on. The exporter could be configured as follows:
+<programlisting>
+  services.promtheus.exporters.node = {
+    enable = true;
+    enabledCollectors = [
+      "logind"
+      "systemd"
+    ];
+    disabledCollectors = [
+      "textfile"
+    ];
+    openFirewall = true;
+    firewallFilter = "-i br0 -p tcp -m tcp --dport 9100";
+  };
+</programlisting>
+It should now serve all metrics from the collectors
+that are explicitly enabled and the ones that are
+<link xlink:href="https://github.com/prometheus/node_exporter#enabled-by-default">enabled by default</link>, via http under <literal>/metrics</literal>. In this example the firewall should just
+allow incoming connections to the exporter's port on the bridge interface <literal>br0</literal>
+(this would have to be configured seperately of course).
+For more information about configuration see <literal>man configuration.nix</literal> or
+search through the <link xlink:href="https://nixos.org/nixos/options.html#prometheus.exporters">available options</link>.
+</para>
+</section>
+<section><title>Adding a new exporter</title>
+  <para>To add a new exporter, it has to be packaged first (see <literal>nixpkgs/pkgs/servers/monitoring/prometheus/</literal> for examples), then a module can be added. The postfix exporter is used in this example:</para>
+<itemizedlist>
+  <listitem>
+    <para>
+      Some default options for all exporters are provided by
+      <literal>nixpkgs/nixos/modules/services/monitoring/prometheus/exporters.nix</literal>:
+    </para>
+  </listitem>
+  <listitem override='none'>
+    <itemizedlist>
+      <listitem><para><literal>enable</literal></para></listitem>
+      <listitem><para><literal>port</literal></para></listitem>
+      <listitem><para><literal>listenAddress</literal></para></listitem>
+      <listitem><para><literal>extraFlags</literal></para></listitem>
+      <listitem><para><literal>openFirewall</literal></para></listitem>
+      <listitem><para><literal>firewallFilter</literal></para></listitem>
+      <listitem><para><literal>user</literal></para></listitem>
+      <listitem><para><literal>group</literal></para></listitem>
+    </itemizedlist>
+  </listitem>
+  <listitem>
+    <para>As there is already a package available, the module can now be added.
+      This is accomplished by adding a new file to the
+      <literal>nixos/modules/services/monitoring/prometheus/exporters/</literal> directory,
+      which will be called postfix.nix and contains all exporter specific options
+      and configuration:
+      <programlisting>
+        # nixpgs/nixos/modules/services/prometheus/exporters/postfix.nix
+        { config, lib, pkgs }:
+
+        with lib;
+
+        let
+          # for convenience we define cfg here
+          cfg = config.services.prometheus.exporters.postfix;
+        in
+        {
+          port = 9154; # The postfix exporter listens on this port by default
+
+          # `extraOpts` is an attribute set which contains additional options
+          # (and optional overrides for default options).
+          # Note that this attribute is optional.
+          extraOpts = {
+            telemetryPath = mkOption {
+              type = types.str;
+              default = "/metrics";
+              description = ''
+                Path under which to expose metrics.
+              '';
+            };
+            logfilePath = mkOption {
+              type = types.path;
+              default = /var/log/postfix_exporter_input.log;
+              example = /var/log/mail.log;
+              description = ''
+                Path where Postfix writes log entries.
+                This file will be truncated by this exporter!
+              '';
+            };
+            showqPath = mkOption {
+              type = types.path;
+              default = /var/spool/postfix/public/showq;
+              example = /var/lib/postfix/queue/public/showq;
+              description = ''
+                Path at which Postfix places its showq socket.
+              '';
+            };
+          };
+
+          # `serviceOpts` is an attribute set which contains configuration
+          # for the exporter's systemd service. One of
+          # `serviceOpts.script` and `serviceOpts.serviceConfig.ExecStart`
+          # has to be specified here. This will be merged with the default
+          # service confiuration.
+          serviceOpts = {
+            serviceConfig = {
+              ExecStart = ''
+                ${pkgs.prometheus-postfix-exporter}/bin/postfix_exporter \
+                  --web.listen-address ${cfg.listenAddress}:${toString cfg.port} \
+                  --web.telemetry-path ${cfg.telemetryPath} \
+                  ${concatStringsSep " \\\n  " cfg.extraFlags}
+              '';
+            };
+          };
+        }
+      </programlisting>
+    </para>
+  </listitem>
+  <listitem>
+    <para>
+      This should already be enough for the postfix exporter. Additionally one could
+      now add assertions and conditional default values. This can be done in the
+      'meta-module' that combines all exporter definitions and generates the submodules:
+      <literal>nixpkgs/nixos/modules/services/prometheus/exporters.nix</literal>
+    </para>
+  </listitem>
+</itemizedlist>
+</section>
+</chapter>
diff --git a/nixos/modules/services/monitoring/prometheus/exporters/blackbox.nix b/nixos/modules/services/monitoring/prometheus/exporters/blackbox.nix
@@ -0,0 +1,31 @@
+{ config, lib, pkgs }:
+
+with lib;
+
+let
+  cfg = config.services.prometheus.exporters.blackbox;
+in
+{
+  port = 9115;
+  extraOpts = {
+    configFile = mkOption {
+      type = types.path;
+      description = ''
+        Path to configuration file.
+      '';
+    };
+  };
+  serviceOpts = {
+    serviceConfig = {
+      AmbientCapabilities = [ "CAP_NET_RAW" ]; # for ping probes
+      DynamicUser = true;
+      ExecStart = ''
+        ${pkgs.prometheus-blackbox-exporter}/bin/blackbox_exporter \
+          --web.listen-address ${cfg.listenAddress}:${toString cfg.port} \
+          --config.file ${cfg.configFile} \
+          ${concatStringsSep " \\\n  " cfg.extraFlags}
+      '';
+      ExecReload = "${pkgs.coreutils}/bin/kill -HUP $MAINPID";
+    };
+  };
+}
diff --git a/nixos/modules/services/monitoring/prometheus/exporters/collectd.nix b/nixos/modules/services/monitoring/prometheus/exporters/collectd.nix
@@ -0,0 +1,78 @@
+{ config, lib, pkgs }:
+
+with lib;
+
+let
+  cfg = config.services.prometheus.exporters.collectd;
+in
+{
+  port = 9103;
+  extraOpts = {
+    collectdBinary = {
+      enable = mkEnableOption "collectd binary protocol receiver";
+
+      authFile = mkOption {
+        default = null;
+        type = types.nullOr types.path;
+        description = "File mapping user names to pre-shared keys (passwords).";
+      };
+
+      port = mkOption {
+        type = types.int;
+        default = 25826;
+        description = ''Network address on which to accept collectd binary network packets.'';
+      };
+
+      listenAddress = mkOption {
+        type = types.str;
+        default = "0.0.0.0";
+        description = ''
+          Address to listen on for binary network packets.
+          '';
+      };
+
+      securityLevel = mkOption {
+        type = types.enum ["None" "Sign" "Encrypt"];
+        default = "None";
+        description = ''
+          Minimum required security level for accepted packets.
+        '';
+      };
+    };
+
+    logFormat = mkOption {
+      type = types.str;
+      default = "logger:stderr";
+      example = "logger:syslog?appname=bob&local=7 or logger:stdout?json=true";
+      description = ''
+        Set the log target and format.
+      '';
+    };
+
+    logLevel = mkOption {
+      type = types.enum ["debug" "info" "warn" "error" "fatal"];
+      default = "info";
+      description = ''
+        Only log messages with the given severity or above.
+      '';
+    };
+  };
+  serviceOpts = let
+    collectSettingsArgs = if (cfg.collectdBinary.enable) then ''
+      -collectd.listen-address ${cfg.collectdBinary.listenAddress}:${toString cfg.collectdBinary.port} \
+      -collectd.security-level ${cfg.collectdBinary.securityLevel} \
+    '' else "";
+  in {
+    serviceConfig = {
+      DynamicUser = true;
+      ExecStart = ''
+        ${pkgs.prometheus-collectd-exporter}/bin/collectd_exporter \
+          -log.format ${cfg.logFormat} \
+          -log.level ${cfg.logLevel} \
+          -web.listen-address ${cfg.listenAddress}:${toString cfg.port} \
+          ${collectSettingsArgs} \
+          ${concatStringsSep " \\\n  " cfg.extraFlags}
+      '';
+    };
+  };
+}
diff --git a/nixos/modules/services/monitoring/prometheus/exporters/fritzbox.nix b/nixos/modules/services/monitoring/prometheus/exporters/fritzbox.nix
@@ -0,0 +1,39 @@
+{ config, lib, pkgs }:
+
+with lib;
+
+let
+  cfg = config.services.prometheus.exporters.fritzbox;
+in
+{
+  port = 9133;
+  extraOpts = {
+    gatewayAddress = mkOption {
+      type = types.str;
+      default = "fritz.box";
+      description = ''
+        The hostname or IP of the FRITZ!Box.
+      '';
+    };
+
+    gatewayPort = mkOption {
+      type = types.int;
+      default = 49000;
+      description = ''
+        The port of the FRITZ!Box UPnP service.
+      '';
+    };
+  };
+  serviceOpts = {
+    serviceConfig = {
+      DynamicUser = true;
+      ExecStart = ''
+        ${pkgs.prometheus-fritzbox-exporter}/bin/fritzbox_exporter \
+          -listen-address ${cfg.listenAddress}:${toString cfg.port} \
+          -gateway-address ${cfg.gatewayAddress} \
+          -gateway-port ${toString cfg.gatewayPort} \
+          ${concatStringsSep " \\\n  " cfg.extraFlags}
+      '';
+    };
+  };
+}
diff --git a/nixos/modules/services/monitoring/prometheus/exporters/json.nix b/nixos/modules/services/monitoring/prometheus/exporters/json.nix
@@ -0,0 +1,36 @@
+{ config, lib, pkgs }:
+
+with lib;
+
+let
+  cfg = config.services.prometheus.exporters.json;
+in
+{
+  port = 7979;
+  extraOpts = {
+    url = mkOption {
+      type = types.str;
+      description = ''
+        URL to scrape JSON from.
+      '';
+    };
+    configFile = mkOption {
+      type = types.path;
+      description = ''
+        Path to configuration file.
+      '';
+    };
+    listenAddress = {}; # not used
+  };
+  serviceOpts = {
+    serviceConfig = {
+      DynamicUser = true;
+      ExecStart = ''
+        ${pkgs.prometheus-json-exporter}/bin/prometheus-json-exporter \
+          --port ${toString cfg.port} \
+          ${cfg.url} ${cfg.configFile} \
+          ${concatStringsSep " \\\n  " cfg.extraFlags}
+      '';
+    };
+  };
+}
diff --git a/nixos/modules/services/monitoring/prometheus/exporters/minio.nix b/nixos/modules/services/monitoring/prometheus/exporters/minio.nix
@@ -0,0 +1,65 @@
+{ config, lib, pkgs }:
+
+with lib;
+
+let
+  cfg = config.services.prometheus.exporters.minio;
+in
+{
+  port = 9290;
+  extraOpts = {
+    minioAddress = mkOption {
+      type = types.str;
+      example = "https://10.0.0.1:9000";
+      description = ''
+        The URL of the minio server.
+        Use HTTPS if Minio accepts secure connections only.
+        By default this connects to the local minio server if enabled.
+      '';
+    };
+
+    minioAccessKey = mkOption {
+      type = types.str;
+      example = "yourMinioAccessKey";
+      description = ''
+        The value of the Minio access key.
+        It is required in order to connect to the server.
+        By default this uses the one from the local minio server if enabled
+        and <literal>config.services.minio.accessKey</literal>.
+      '';
+    };
+
+    minioAccessSecret = mkOption {
+      type = types.str;
+      description = ''
+        The value of the Minio access secret.
+        It is required in order to connect to the server.
+        By default this uses the one from the local minio server if enabled
+        and <literal>config.services.minio.secretKey</literal>.
+      '';
+    };
+
+    minioBucketStats = mkOption {
+      type = types.bool;
+      default = false;
+      description = ''
+        Collect statistics about the buckets and files in buckets.
+        It requires more computation, use it carefully in case of large buckets..
+      '';
+    };
+  };
+  serviceOpts = {
+    serviceConfig = {
+      DynamicUser = true;
+      ExecStart = ''
+        ${pkgs.prometheus-minio-exporter}/bin/minio-exporter \
+          -web.listen-address ${cfg.listenAddress}:${toString cfg.port} \
+          -minio.server ${cfg.minioAddress} \
+          -minio.access-key ${cfg.minioAccessKey} \
+          -minio.access-secret ${cfg.minioAccessSecret} \
+          ${optionalString cfg.minioBucketStats "-minio.bucket-stats"} \
+          ${concatStringsSep " \\\n  " cfg.extraFlags}
+      '';
+    };
+  };
+}
diff --git a/nixos/modules/services/monitoring/prometheus/exporters/nginx.nix 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}
+      '';
+    };
+  };
+}
diff --git a/nixos/modules/services/monitoring/prometheus/exporters/node.nix b/nixos/modules/services/monitoring/prometheus/exporters/node.nix
@@ -0,0 +1,39 @@
+{ config, lib, pkgs }:
+
+with lib;
+
+let
+  cfg = config.services.prometheus.exporters.node;
+in
+{
+  port = 9100;
+  extraOpts = {
+    enabledCollectors = mkOption {
+      type = types.listOf types.string;
+      default = [];
+      example = ''[ "systemd" ]'';
+      description = ''
+        Collectors to enable. The collectors listed here are enabled in addition to the default ones.
+      '';
+    };
+    disabledCollectors = mkOption {
+      type = types.listOf types.str;
+      default = [];
+      example = ''[ "timex" ]'';
+      description = ''
+        Collectors to disable which are enabled by default.
+      '';
+    };
+  };
+  serviceOpts = {
+    serviceConfig = {
+      ExecStart = ''
+        ${pkgs.prometheus-node-exporter}/bin/node_exporter \
+          ${concatMapStringsSep " " (x: "--collector." + x) cfg.enabledCollectors} \
+          ${concatMapStringsSep " " (x: "--no-collector." + x) cfg.disabledCollectors} \
+          --web.listen-address ${cfg.listenAddress}:${toString cfg.port} \
+          ${concatStringsSep " \\\n  " cfg.extraFlags}
+      '';
+    };
+  };
+}
diff --git a/nixos/modules/services/monitoring/prometheus/exporters/postfix.nix b/nixos/modules/services/monitoring/prometheus/exporters/postfix.nix
@@ -0,0 +1,46 @@
+{ config, lib, pkgs }:
+
+with lib;
+
+let
+  cfg = config.services.prometheus.exporters.postfix;
+in
+{
+  port = 9154;
+  extraOpts = {
+    telemetryPath = mkOption {
+      type = types.str;
+      default = "/metrics";
+      description = ''
+        Path under which to expose metrics.
+      '';
+    };
+    logfilePath = mkOption {
+      type = types.path;
+      default = "/var/log/postfix_exporter_input.log";
+      example = "/var/log/mail.log";
+      description = ''
+        Path where Postfix writes log entries.
+        This file will be truncated by this exporter!
+      '';
+    };
+    showqPath = mkOption {
+      type = types.path;
+      default = "/var/spool/postfix/public/showq";
+      example = "/var/lib/postfix/queue/public/showq";
+      description = ''
+        Path where Postfix places it's showq socket.
+      '';
+    };
+  };
+  serviceOpts = {
+    serviceConfig = {
+      ExecStart = ''
+        ${pkgs.prometheus-postfix-exporter}/bin/postfix_exporter \
+          --web.listen-address ${cfg.listenAddress}:${toString cfg.port} \
+          --web.telemetry-path ${cfg.telemetryPath} \
+          ${concatStringsSep " \\\n  " cfg.extraFlags}
+      '';
+    };
+  };
+}
diff --git a/nixos/modules/services/monitoring/prometheus/exporters/snmp.nix b/nixos/modules/services/monitoring/prometheus/exporters/snmp.nix
@@ -0,0 +1,71 @@
+{ config, lib, pkgs }:
+
+with lib;
+
+let
+  cfg = config.services.prometheus.exporters.snmp;
+in
+{
+  port = 9116;
+  extraOpts = {
+    configurationPath = mkOption {
+      type = types.nullOr types.path;
+      default = null;
+      description = ''
+        Path to a snmp exporter configuration file. Mutually exclusive with 'configuration' option.
+      '';
+      example = "./snmp.yml";
+    };
+
+    configuration = mkOption {
+      type = types.nullOr types.attrs;
+      default = {};
+      description = ''
+        Snmp exporter configuration as nix attribute set. Mutually exclusive with 'configurationPath' option.
+      '';
+      example = ''
+        {
+          "default" = {
+            "version" = 2;
+            "auth" = {
+              "community" = "public";
+            };
+          };
+        };
+      '';
+    };
+
+    logFormat = mkOption {
+      type = types.str;
+      default = "logger:stderr";
+      description = ''
+        Set the log target and format.
+      '';
+    };
+
+    logLevel = mkOption {
+      type = types.enum ["debug" "info" "warn" "error" "fatal"];
+      default = "info";
+      description = ''
+        Only log messages with the given severity or above.
+      '';
+    };
+  };
+  serviceOpts = let
+    configFile = if cfg.configurationPath != null
+                 then cfg.configurationPath
+                 else "${pkgs.writeText "snmp-eporter-conf.yml" (builtins.toJSON cfg.configuration)}";
+    in {
+    serviceConfig = {
+      DynamicUser = true;
+      ExecStart = ''
+        ${pkgs.prometheus-snmp-exporter.bin}/bin/snmp_exporter \
+          -config.file ${configFile} \
+          -log.format ${cfg.logFormat} \
+          -log.level ${cfg.logLevel} \
+          -web.listen-address ${cfg.listenAddress}:${toString cfg.port} \
+          ${concatStringsSep " \\\n  " cfg.extraFlags}
+      '';
+    };
+  };
+}
diff --git a/nixos/modules/services/monitoring/prometheus/exporters/unifi.nix b/nixos/modules/services/monitoring/prometheus/exporters/unifi.nix
@@ -0,0 +1,67 @@
+{ config, lib, pkgs }:
+
+with lib;
+
+let
+  cfg = config.services.prometheus.exporters.unifi;
+in
+{
+  port = 9130;
+  extraOpts = {
+    unifiAddress = mkOption {
+      type = types.str;
+      example = "https://10.0.0.1:8443";
+      description = ''
+        URL of the UniFi Controller API.
+      '';
+    };
+
+    unifiInsecure = mkOption {
+      type = types.bool;
+      default = false;
+      description = ''
+        If enabled skip the verification of the TLS certificate of the UniFi Controller API.
+        Use with caution.
+      '';
+    };
+
+    unifiUsername = mkOption {
+      type = types.str;
+      example = "ReadOnlyUser";
+      description = ''
+        username for authentication against UniFi Controller API.
+      '';
+    };
+
+    unifiPassword = mkOption {
+      type = types.str;
+      description = ''
+        Password for authentication against UniFi Controller API.
+      '';
+    };
+
+    unifiTimeout = mkOption {
+      type = types.str;
+      default = "5s";
+      example = "2m";
+      description = ''
+        Timeout including unit for UniFi Controller API requests.
+      '';
+    };
+  };
+  serviceOpts = {
+    serviceConfig = {
+      DynamicUser = true;
+      ExecStart = ''
+        ${pkgs.prometheus-unifi-exporter}/bin/unifi_exporter \
+          -telemetry.addr ${cfg.listenAddress}:${toString cfg.port} \
+          -unifi.addr ${cfg.unifiAddress} \
+          -unifi.username ${cfg.unifiUsername} \
+          -unifi.password ${cfg.unifiPassword} \
+          -unifi.timeout ${cfg.unifiTimeout} \
+          ${optionalString cfg.unifiInsecure "-unifi.insecure" } \
+          ${concatStringsSep " \\\n  " cfg.extraFlags}
+      '';
+    };
+  };
+}
diff --git a/nixos/modules/services/monitoring/prometheus/exporters/varnish.nix b/nixos/modules/services/monitoring/prometheus/exporters/varnish.nix
@@ -0,0 +1,21 @@
+{ config, lib, pkgs }:
+
+with lib;
+
+let
+  cfg = config.services.prometheus.exporters.varnish;
+in
+{
+  port = 9131;
+  serviceOpts = {
+    path = [ pkgs.varnish ];
+    serviceConfig = {
+      DynamicUser = true;
+      ExecStart = ''
+        ${pkgs.prometheus-varnish-exporter}/bin/prometheus_varnish_exporter \
+          -web.listen-address ${cfg.listenAddress}:${toString cfg.port} \
+          ${concatStringsSep " \\\n  " cfg.extraFlags}
+      '';
+    };
+  };
+}
diff --git a/nixos/modules/services/monitoring/prometheus/fritzbox-exporter.nix b/nixos/modules/services/monitoring/prometheus/fritzbox-exporter.nix
diff --git a/nixos/modules/services/monitoring/prometheus/json-exporter.nix b/nixos/modules/services/monitoring/prometheus/json-exporter.nix
diff --git a/nixos/modules/services/monitoring/prometheus/minio-exporter.nix b/nixos/modules/services/monitoring/prometheus/minio-exporter.nix
diff --git a/nixos/modules/services/monitoring/prometheus/nginx-exporter.nix b/nixos/modules/services/monitoring/prometheus/nginx-exporter.nix
diff --git a/nixos/modules/services/monitoring/prometheus/node-exporter.nix b/nixos/modules/services/monitoring/prometheus/node-exporter.nix
diff --git a/nixos/modules/services/monitoring/prometheus/snmp-exporter.nix b/nixos/modules/services/monitoring/prometheus/snmp-exporter.nix
diff --git a/nixos/modules/services/monitoring/prometheus/unifi-exporter.nix b/nixos/modules/services/monitoring/prometheus/unifi-exporter.nix
diff --git a/nixos/modules/services/monitoring/prometheus/varnish-exporter.nix b/nixos/modules/services/monitoring/prometheus/varnish-exporter.nix