nixos/grafana-image-renderer: init

nixos/modules/module-list.nix

@@ -537,6 +537,7 @@
   ./services/monitoring/do-agent.nix
   ./services/monitoring/fusion-inventory.nix
   ./services/monitoring/grafana.nix
+  ./services/monitoring/grafana-image-renderer.nix
   ./services/monitoring/grafana-reporter.nix
   ./services/monitoring/graphite.nix
   ./services/monitoring/hdaps.nix

nixos/modules/services/monitoring/grafana-image-renderer.nix

@@ -0,0 +1,150 @@
+{ lib, pkgs, config, ... }:
+
+with lib;
+
+let
+  cfg = config.services.grafana-image-renderer;
+
+  format = pkgs.formats.json { };
+
+  configFile = format.generate "grafana-image-renderer-config.json" cfg.settings;
+in {
+  options.services.grafana-image-renderer = {
+    enable = mkEnableOption "grafana-image-renderer";
+
+    chromium = mkOption {
+      type = types.package;
+      description = ''
+        The chromium to use for image rendering.
+      '';
+    };
+
+    verbose = mkEnableOption "verbosity for the service";
+
+    provisionGrafana = mkEnableOption "Grafana configuration for grafana-image-renderer";
+
+    settings = mkOption {
+      type = types.submodule {
+        freeformType = format.type;
+
+        options = {
+          service = {
+            port = mkOption {
+              type = types.port;
+              default = 8081;
+              description = ''
+                The TCP port to use for the rendering server.
+              '';
+            };
+            logging.level = mkOption {
+              type = types.enum [ "error" "warning" "info" "debug" ];
+              default = "info";
+              description = ''
+                The log-level of the <filename>grafana-image-renderer.service</filename>-unit.
+              '';
+            };
+          };
+          rendering = {
+            width = mkOption {
+              default = 1000;
+              type = types.ints.positive;
+              description = ''
+                Width of the PNG used to display the alerting graph.
+              '';
+            };
+            height = mkOption {
+              default = 500;
+              type = types.ints.positive;
+              description = ''
+                Height of the PNG used to display the alerting graph.
+              '';
+            };
+            mode = mkOption {
+              default = "default";
+              type = types.enum [ "default" "reusable" "clustered" ];
+              description = ''
+                Rendering mode of <package>grafana-image-renderer</package>:
+                <itemizedlist>
+                <listitem><para><literal>default:</literal> Creates on browser-instance
+                  per rendering request.</para></listitem>
+                <listitem><para><literal>reusable:</literal> One browser instance
+                  will be started and reused for each rendering request.</para></listitem>
+                <listitem><para><literal>clustered:</literal> allows to precisely
+                  configure how many browser-instances are supposed to be used. The values
+                  for that mode can be declared in <literal>rendering.clustering</literal>.
+                  </para></listitem>
+                </itemizedlist>
+              '';
+            };
+            args = mkOption {
+              type = types.listOf types.str;
+              default = [ "--no-sandbox" ];
+              description = ''
+                List of CLI flags passed to <package>chromium</package>.
+              '';
+            };
+          };
+        };
+      };
+
+      default = {};
+
+      description = ''
+        Configuration attributes for <package>grafana-image-renderer</package>.
+
+        See <link xlink:href="https://github.com/grafana/grafana-image-renderer/blob/ce1f81438e5f69c7fd7c73ce08bab624c4c92e25/default.json" />
+        for supported values.
+      '';
+    };
+  };
+
+  config = mkIf cfg.enable {
+    assertions = [
+      { assertion = cfg.provisionGrafana -> config.services.grafana.enable;
+        message = ''
+          To provision a Grafana instance to use grafana-image-renderer,
+          `services.grafana.enable` must be set to `true`!
+        '';
+      }
+    ];
+
+    services.grafana.extraOptions = mkIf cfg.provisionGrafana {
+      RENDERING_SERVER_URL = "http://localhost:${toString cfg.settings.service.port}/render";
+      RENDERING_CALLBACK_URL = "http://localhost:${toString config.services.grafana.port}";
+    };
+
+    services.grafana-image-renderer.chromium = mkDefault pkgs.chromium;
+
+    services.grafana-image-renderer.settings = {
+      rendering = mapAttrs (const mkDefault) {
+        chromeBin = "${cfg.chromium}/bin/chromium";
+        verboseLogging = cfg.verbose;
+        timezone = config.time.timeZone;
+      };
+
+      services = {
+        logging.level = mkIf cfg.verbose (mkDefault "debug");
+        metrics.enabled = mkDefault false;
+      };
+    };
+
+    systemd.services.grafana-image-renderer = {
+      wantedBy = [ "multi-user.target" ];
+      after = [ "network.target" ];
+      description = " A Grafana backend plugin that handles rendering of panels & dashboards to PNGs using headless browser (Chromium/Chrome)";
+
+      environment = {
+        PUPPETEER_SKIP_CHROMIUM_DOWNLOAD = "true";
+      };
+
+      serviceConfig = {
+        DynamicUser = true;
+        PrivateTmp = true;
+        ExecStart = "${pkgs.grafana-image-renderer}/bin/grafana-image-renderer server --config=${configFile}";
+        Restart = "always";
+      };
+    };
+  };
+
+  meta.maintainers = with maintainers; [ ma27 ];
+}