feat(metrics): better metrics and support for failed and successful requests

src/lib/helpers/youtubePlayerHandling.ts

@@ -2,7 +2,7 @@ import { ApiResponse, Innertube, YT } from "youtubei.js";
 import { generateRandomString } from "youtubei.js/Utils";
 import { compress, decompress } from "https://deno.land/x/brotli@0.1.7/mod.ts";
 import { Store } from "@willsoto/node-konfig-core";
-import { cachedEntries } from "../../routes/index.ts";
+import { failedRequests, successfulRequests } from "../../routes/index.ts";
 let youtubePlayerReqLocation = "youtubePlayerReq";
 if (Deno.env.get("YT_PLAYER_REQ_LOCATION")) {
     if (Deno.env.has("DENO_COMPILED")) {
@@ -18,7 +18,7 @@ const { youtubePlayerReq } = await import(youtubePlayerReqLocation);
 
 const videoCachePath = Deno.env.get("VIDEO_CACHE_PATH") as string || "/var/tmp/youtubei.js/video_cache"
 
-let kv : Deno.Kv
+export let kv : Deno.Kv
 if ((Deno.env.get("VIDEO_CACHE_ON_DISK")?.toLowerCase() ?? false) == "true") {
     console.log("[INFO] Storing video cache on disk")
     kv = await Deno.openKv(videoCachePath);
@@ -138,23 +138,27 @@ export const youtubePlayerParsing = async (
             },
         }))(videoData);
 
-        if (
-            cacheEnabled == true && videoData.playabilityStatus?.status == "OK"
-        ) {
-            (async () => {
-                await kv.set(
-                    ["video_cache", videoId],
-                    compress(
-                        new TextEncoder().encode(
-                            JSON.stringify(videoOnlyNecessaryInfo),
+        if (videoData.playabilityStatus?.status == "OK") {
+            successfulRequests.inc()
+            if (
+                cacheEnabled == true
+            ) {
+                (async () => {
+                    await kv.set(
+                        ["video_cache", videoId],
+                        compress(
+                            new TextEncoder().encode(
+                                JSON.stringify(videoOnlyNecessaryInfo),
+                            ),
                         ),
-                    ),
-                    {
-                        expireIn: 1000 * 60 * 60,
-                    },
-                );
-                cachedEntries.inc()
-            })();
+                        {
+                            expireIn: 1000 * 60 * 60,
+                        },
+                    );
+                })();
+            }
+        } else {
+            failedRequests.inc()
         }
 
         return videoOnlyNecessaryInfo;

src/routes/index.ts

@@ -2,7 +2,7 @@ import { Hono } from "hono";
 import { logger } from "hono/logger";
 import { Store } from "@willsoto/node-konfig-core";
 import { bearerAuth } from "hono/bearer-auth";
-import { Registry, Counter } from "prom-client"
+import { Registry, Counter, Gauge } from "prom-client"
 
 import youtubeApiPlayer from "./youtube_api_routes/player.ts";
 import invidiousRouteLatestVersion from "./invidious_routes/latestVersion.ts";
@@ -19,7 +19,7 @@ export const externalTokenGeneratorFail = new Counter({
 	registers: [register]
   });
 
-export const cachedEntries = new Counter({
+export const cachedEntries = new Gauge({
 	name: `${METRICS_PREFIX}cached_entries`,
 	help: 'TODO',
 	registers: [register]
@@ -54,6 +54,20 @@ export const videoRestricted = new Counter({
 	help: 'TODO',
 	registers: [register]
   });
+
+
+export const failedRequests = new Counter({
+	name: `${METRICS_PREFIX}failed_requests`,
+	help: 'TODO',
+	registers: [register]
+});
+
+export const successfulRequests = new Counter({
+	name: `${METRICS_PREFIX}successful_requests`,
+	help: 'TODO',
+	registers: [register]
+});
+
 import health from "./health.ts";
 
 export const routes = (app: Hono, konfigStore: Store<Record<string, unknown>>) => {

src/routes/metrics.ts

@@ -1,9 +1,16 @@
 import { Hono } from "hono";
-import { register } from "./index.ts";
+import { register, cachedEntries } from "./index.ts";
+import { kv } from "../lib/helpers/youtubePlayerHandling.ts"
 
 const metrics = new Hono();
   
 metrics.get("/", async () => {
+  let i = 0;
+  const entries = kv.list({ prefix: ["video_cache"] })
+  for await (const _ of entries) {
+    i += 1
+  }
+  cachedEntries.set(i)
   return new Response(await register.metrics(), {
     headers: { "Content-Type": "text/plain" },
   });