use a fasthttp request for metrics push

packages/doorman-api/src/common/DoormanHandler.ts

@@ -3,6 +3,7 @@ import { PrometheusContentType, Registry, Pushgateway, Summary, Counter, registe
 import { DoormanLambdaContext } from "./DoormanHandlerContext";
 import { shouldBlockRequest } from "../utils/blockUserAgent";
 import { RequestOptions } from "https";
+import { FastHttpPushgateway } from "../metrics/FastHttpPromGateway";
 
 export type BaseEvent = { request: { cookies: {}; headers: {}; }; }
 
@@ -44,7 +45,7 @@ export function withMetrics<T extends DoormanLambdaContext, U extends BaseEvent>
       },
     };
 
-    const pushGateway = new Pushgateway(context.PUSHGATEWAY_URL, requestOptions, metricsRegistry);
+    const pushGateway = new FastHttpPushgateway(context.PUSHGATEWAY_URL, requestOptions, metricsRegistry);
 
     metricsRegistry.registerMetric(new Summary({
       name: CommonMetrics.RUNTIME,
@@ -111,7 +112,7 @@ export function withMetrics<T extends DoormanLambdaContext, U extends BaseEvent>
     console.log(`[CommonHandler] there is ${remainingTime} ms left to send metrics`);
 
     let metricsTimeout = setTimeout(() => {
-      console.error("[CommonHandler] cutting it too close, abandoning metrics");
+      console.log("[CommonHandler] cutting it too close, abandoning metrics");
       callback(...result);
     }, remainingTime - 250);
 
@@ -127,10 +128,8 @@ export function withMetrics<T extends DoormanLambdaContext, U extends BaseEvent>
       });
       console.log("[CommonHandler] pushed metrics successfully");
     } catch (e: any) {
-      console.error("[CommonHandler] failed to push metrics, quietly discarding them", e);
+      console.log("[CommonHandler] failed to push metrics, quietly discarding them", e);
     }
-
-    
     
     clearTimeout(metricsTimeout);
     callback(...result);

packages/doorman-api/src/metrics/FastHttpPromGateway.ts

@@ -0,0 +1,90 @@
+import { Pushgateway, Registry, RegistryContentType } from "prom-client";
+import url from "url";
+import http from "http";
+import https from "https";
+import { gzipSync } from "zlib";
+
+// copied mostly from pushgateway.js implementation. Just swapping out the http call to not await a response
+
+export class FastHttpPushgateway<T extends RegistryContentType> extends Pushgateway<T> {
+	constructor(url: string, options?: any, registry?: Registry<T>) {
+		super(url, options, registry);
+	}
+
+  override push(params: Pushgateway.Parameters): Promise<{ resp?: unknown; body?: unknown; }> {
+		let method = "PUT";
+		let job = params.jobName;
+		let groupings = params.groupings;
+		
+		// @ts-ignore
+		let gatewayUrl: string = this.gatewayUrl;
+		// @ts-ignore
+		let requestOptions: any = this.requestOptions;
+
+		// @ts-ignore
+		let registry: Registry = this.registry;
+
+		// `URL` first added in v6.13.0
+		// eslint-disable-next-line n/no-deprecated-api
+		const gatewayUrlParsed = url.parse(gatewayUrl);
+		const gatewayUrlPath =
+			gatewayUrlParsed.pathname && gatewayUrlParsed.pathname !== '/'
+				? gatewayUrlParsed.pathname
+				: '';
+		const jobPath = job
+			? `/job/${encodeURIComponent(job)}${generateGroupings(groupings)}`
+			: '';
+		const path = `${gatewayUrlPath}/metrics${jobPath}`;
+
+		// eslint-disable-next-line n/no-deprecated-api
+		const target = url.resolve(gatewayUrl, path);
+		// eslint-disable-next-line n/no-deprecated-api
+		const requestParams = url.parse(target);
+		const httpModule = isHttps(requestParams.href) ? https : http;
+		const options = Object.assign(requestParams, requestOptions, {
+			method,
+		});
+
+		return new Promise((resolve, reject) => {
+			if (method === 'DELETE' && options.headers) {
+				delete options.headers['Content-Encoding'];
+			}
+			const req = httpModule.request(options);
+
+			// write metrics
+			registry
+				.metrics()
+				.then(metrics => {
+					if (
+						options.headers &&
+						options.headers['Content-Encoding'] === 'gzip'
+					) {
+						metrics = gzipSync(metrics) as any;
+					}
+
+					// write metrics, and once thats done, end req. Don't wait for response
+					req.write(metrics, () => {
+						req.end(() => {
+							resolve({});
+						});
+					});
+				})
+		});
+	}
+}
+
+function generateGroupings(groupings: any) {
+	if (!groupings) {
+		return '';
+	}
+	return Object.keys(groupings)
+		.map(
+			key =>
+				`/${encodeURIComponent(key)}/${encodeURIComponent(groupings[key])}`,
+		)
+		.join('');
+}
+
+function isHttps(href: string) {
+	return href.search(/^https/) !== -1;
+}

packages/doorman-client/src/functions/buzzer-activated.ts

@@ -135,11 +135,11 @@ export const handler: ServerlessFunctionSignature<TwilioContext, BuzzerDialEvent
         .inc({ door: config.door }, 1);
 
       const twiml = dialFallbackTwiml(config);
-      console.error(
+      console.log(
         invokeId, "UngracefulFallbackPromise: Cutting it too close to timeout! Skipping notifying users and calling fallback"
       );
       resolve(twiml);
-    }, 9500));
+    }, 9000));
   });
 
   const twiml = await Promise.race([unlockPromise, gracefulFallbackPromise, ungracefulFallbackPromise]);