nixos/karma: init

nixos/doc/manual/from_md/release-notes/rl-2211.section.xml

···
       </listitem>
       <listitem>
         <para>
+          <link xlink:href="https://github.com/prymitive/karma">karma</link>,
+          an alert dashboard for Prometheus Alertmanager. Available as
+          <link xlink:href="options.html#opt-services.karma.enable">services.karma</link>
+        </para>
+      </listitem>
+      <listitem>
+        <para>
           <link xlink:href="https://languagetool.org/">languagetool</link>,
           a multilingual grammar, style, and spell checker. Available as
           <link xlink:href="options.html#opt-services.languagetool.enable">services.languagetool</link>.

nixos/doc/manual/release-notes/rl-2211.section.md

···
 - [kanata](https://github.com/jtroo/kanata), a tool to improve keyboard comfort and usability with advanced customization.
   Available as [services.kanata](options.html#opt-services.kanata.enable).
 
+- [karma](https://github.com/prymitive/karma), an alert dashboard for Prometheus Alertmanager. Available as [services.karma](options.html#opt-services.karma.enable)
+
 - [languagetool](https://languagetool.org/), a multilingual grammar, style, and spell checker.
   Available as [services.languagetool](options.html#opt-services.languagetool.enable).
 

nixos/modules/module-list.nix

···
   ./services/monitoring/heapster.nix
   ./services/monitoring/incron.nix
   ./services/monitoring/kapacitor.nix
+  ./services/monitoring/karma.nix
   ./services/monitoring/kthxbye.nix
   ./services/monitoring/loki.nix
   ./services/monitoring/longview.nix

nixos/modules/services/monitoring/karma.nix

···
+{ config, pkgs, lib, ... }:
+with lib;
+let
+  cfg = config.services.karma;
+  yaml = pkgs.formats.yaml { };
+in
+{
+  options.services.karma = {
+    enable = mkEnableOption (mdDoc "the Karma dashboard service");
+
+    package = mkOption {
+      type = types.package;
+      default = pkgs.karma;
+      defaultText = literalExpression "pkgs.karma";
+      description = mdDoc ''
+        The Karma package that should be used.
+      '';
+    };
+
+    configFile = mkOption {
+      type = types.path;
+      default = yaml.generate "karma.yaml" cfg.settings;
+      defaultText = "A configuration file generated from the provided nix attributes settings option.";
+      description = mdDoc ''
+        A YAML config file which can be used to configure karma instead of the nix-generated file.
+      '';
+      example = "/etc/karma/karma.conf";
+    };
+
+    environment = mkOption {
+      type = with types; attrsOf str;
+      default = {};
+      description = mdDoc ''
+        Additional environment variables to provide to karma.
+      '';
+      example = {
+        ALERTMANAGER_URI = "https://alertmanager.example.com";
+        ALERTMANAGER_NAME= "single";
+      };
+    };
+
+    openFirewall = mkOption {
+      type = types.bool;
+      default = false;
+      description = mdDoc ''
+        Whether to open ports in the firewall needed for karma to function.
+      '';
+    };
+
+    extraOptions = mkOption {
+      type = with types; listOf str;
+      default = [];
+      description = mdDoc ''
+        Extra command line options.
+      '';
+      example = [
+        "--alertmanager.timeout 10s"
+      ];
+    };
+
+    settings = mkOption {
+      type = types.submodule {
+        freeformType = yaml.type;
+
+        options.listen = {
+          address = mkOption {
+            type = types.str;
+            default = "127.0.0.1";
+            description = mdDoc ''
+              Hostname or IP to listen on.
+            '';
+            example = "[::]";
+          };
+
+          port = mkOption {
+            type = types.port;
+            default = 8080;
+            description = mdDoc ''
+              HTTP port to listen on.
+            '';
+            example = 8182;
+          };
+        };
+      };
+      default = {
+        listen = {
+          address = "127.0.0.1";
+        };
+      };
+      description = mdDoc ''
+        Karma dashboard configuration as nix attributes.
+
+        Reference: <https://github.com/prymitive/karma/blob/main/docs/CONFIGURATION.md>
+      '';
+      example = {
+        listen = {
+          address = "192.168.1.4";
+          port = "8000";
+          prefix = "/dashboard";
+        };
+        alertmanager = {
+          interval = "15s";
+          servers = [
+            {
+              name = "prod";
+              uri = "http://alertmanager.example.com";
+            }
+          ];
+        };
+      };
+    };
+  };
+
+  config = mkIf cfg.enable {
+    systemd.services.karma = {
+      description = "Alert dashboard for Prometheus Alertmanager";
+      wantedBy = [ "multi-user.target" ];
+      environment = cfg.environment;
+      serviceConfig = {
+        Type = "simple";
+        DynamicUser = true;
+        Restart = "on-failure";
+        ExecStart = "${pkgs.karma}/bin/karma --config.file ${cfg.configFile} ${concatStringsSep " " cfg.extraOptions}";
+      };
+    };
+    networking.firewall.allowedTCPPorts = mkIf cfg.openFirewall [ cfg.settings.listen.port ];
+  };
+}

nixos/tests/all-tests.nix

···
   k3s = handleTest ./k3s {};
   kafka = handleTest ./kafka.nix {};
   kanidm = handleTest ./kanidm.nix {};
+  karma = handleTest ./karma.nix {};
   kbd-setfont-decompress = handleTest ./kbd-setfont-decompress.nix {};
   kbd-update-search-paths-patch = handleTest ./kbd-update-search-paths-patch.nix {};
   kea = handleTest ./kea.nix {};

nixos/tests/karma.nix

···
+import ./make-test-python.nix ({ lib, pkgs, ... }: {
+  name = "karma";
+  nodes = {
+    server = { ... }: {
+      services.prometheus.alertmanager = {
+        enable = true;
+        logLevel = "debug";
+        port = 9093;
+        openFirewall = true;
+        configuration = {
+          global = {
+            resolve_timeout = "1m";
+          };
+          route = {
+            # Root route node
+            receiver = "test";
+            group_by = ["..."];
+            continue = false;
+            group_wait = "1s";
+            group_interval="15s";
+            repeat_interval = "24h";
+          };
+          receivers = [
+            {
+              name = "test";
+              webhook_configs = [
+                {
+                  url = "http://localhost:1234";
+                  send_resolved = true;
+                  max_alerts = 0;
+                }
+              ];
+            }
+          ];
+        };
+      };
+      services.karma = {
+        enable = true;
+        openFirewall = true;
+        settings = {
+          listen = {
+            address = "0.0.0.0";
+            port = 8081;
+          };
+          alertmanager = {
+            servers = [
+              {
+                name = "alertmanager";
+                uri = "https://127.0.0.1:9093";
+              }
+            ];
+          };
+          karma.name = "test-dashboard";
+          log.config = true;
+          log.requests = true;
+          log.timestamp = true;
+        };
+      };
+    };
+  };
+
+  testScript = ''
+    start_all()
+
+    with subtest("Wait for server to come up"):
+
+      server.wait_for_unit("alertmanager.service")
+      server.wait_for_unit("karma.service")
+
+      server.sleep(5) # wait for both services to settle
+
+      server.wait_for_open_port(9093)
+      server.wait_for_open_port(8081)
+
+    with subtest("Test alertmanager readiness"):
+      server.succeed("curl -s http://127.0.0.1:9093/-/ready")
+
+      # Karma only starts serving the dashboard once it has established connectivity to all alertmanagers in its config
+      # Therefore, this will fail if karma isn't able to reach alertmanager
+      server.succeed("curl -s http://127.0.0.1:8081")
+
+    server.shutdown()
+  '';
+})