add support for prometheus metrics

deno.json

@@ -7,6 +7,7 @@
     "hono": "jsr:@hono/hono@^4.6.5",
     "hono/logger": "jsr:@hono/hono@^4.6.5/logger",
     "hono/bearer-auth": "jsr:@hono/hono@^4.6.5/bearer-auth",
+    "prom-client": "npm:prom-client@^15.1.3",
     "youtubei.js": "https://raw.githubusercontent.com/LuanRT/YouTube.js/refs/tags/v12.2.0-deno/deno.ts",
     "youtubei.js/Utils": "https://raw.githubusercontent.com/LuanRT/YouTube.js/refs/tags/v12.2.0-deno/deno/src/utils/Utils.ts",
     "youtubei.js/NavigationEndpoint": "https://raw.githubusercontent.com/LuanRT/YouTube.js/refs/tags/v12.2.0-deno/deno/src/parser/classes/NavigationEndpoint.ts",

src/lib/helpers/youtubePlayerHandling.ts

@@ -2,6 +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";
 let youtubePlayerReqLocation = "youtubePlayerReq";
 if (Deno.env.get("YT_PLAYER_REQ_LOCATION")) {
     if (Deno.env.has("DENO_COMPILED")) {
@@ -134,6 +135,7 @@ export const youtubePlayerParsing = async (
                         expireIn: 1000 * 60 * 60,
                     },
                 );
+                cachedEntries.inc()
             })();
         }
 

src/lib/jobs/potoken.ts

@@ -3,6 +3,7 @@ import type { BgConfig } from "bgutils";
 import { JSDOM } from "jsdom";
 import { Innertube, UniversalCache } from "youtubei.js";
 import { Store } from "@willsoto/node-konfig-core";
+import { poTokenFail, externalTokenGeneratorFail } from "../../routes/index.ts";
 let getFetchClientLocation = "getFetchClient";
 if (Deno.env.get("GET_FETCH_CLIENT_LOCATION")) {
     if (Deno.env.has("DENO_COMPILED")) {
@@ -70,6 +71,7 @@ export const poTokenGenerate = async (
                     e,
             );
             console.log("poTokenGenerate: Using built-in token generator");
+            externalTokenGeneratorFail.inc()
         }
     }
 
@@ -100,6 +102,7 @@ export const poTokenGenerate = async (
     const bgChallenge = await BG.Challenge.create(bgConfig);
 
     if (!bgChallenge) {
+        poTokenFail.inc()
         throw new Error("Could not get challenge");
     }
 
@@ -108,7 +111,10 @@ export const poTokenGenerate = async (
 
     if (interpreterJavascript) {
         new Function(interpreterJavascript)();
-    } else throw new Error("Could not load VM");
+    } else { 
+        poTokenFail.inc()
+        throw new Error("Could not load VM");
+    }
 
     const poTokenResult = await BG.PoToken.generate({
         program: bgChallenge.program,

src/routes/index.ts

@@ -2,11 +2,58 @@ 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 youtubeApiPlayer from "./youtube_api_routes/player.ts";
 import invidiousRouteLatestVersion from "./invidious_routes/latestVersion.ts";
 import invidiousRouteDashManifest from "./invidious_routes/dashManifest.ts";
 import videoPlaybackProxy from "./videoPlaybackProxy.ts";
+import metrics from "./metrics.ts";
+
+const METRICS_PREFIX = "invidious_companion_";
+export const register = new Registry();
+
+export const externalTokenGeneratorFail = new Counter({
+	name: `${METRICS_PREFIX}externaltokengenerator_fail`,
+	help: 'TODO',
+	registers: [register]
+  });
+
+export const cachedEntries = new Counter({
+	name: `${METRICS_PREFIX}cached_entries`,
+	help: 'TODO',
+	registers: [register]
+  });
+
+export const subreasonProtectCommunity = new Counter({
+	name: `${METRICS_PREFIX}subreason_protect_community`,
+	help: 'TODO',
+	registers: [register]
+  });
+
+export const poTokenFail = new Counter({
+	name: `${METRICS_PREFIX}potoken_fail`,
+	help: 'TODO',
+	registers: [register]
+  });
+
+export const reasonBot = new Counter({
+	name: `${METRICS_PREFIX}reason_bot`,
+	help: 'TODO',
+	registers: [register]
+  });
+
+export const videoUnavailable = new Counter({
+	name: `${METRICS_PREFIX}video_unavailable`,
+	help: 'TODO',
+	registers: [register]
+  });
+
+export const videoRestricted = new Counter({
+	name: `${METRICS_PREFIX}video_restricted`,
+	help: 'TODO',
+	registers: [register]
+  });
 
 export const routes = (app: Hono, konfigStore: Store<Record<string, unknown>>) => {
   app.use("*", logger());
@@ -22,4 +69,5 @@ export const routes = (app: Hono, konfigStore: Store<Record<string, unknown>>) =
   app.route("/latest_version", invidiousRouteLatestVersion);
   app.route("/api/manifest/dash/id", invidiousRouteDashManifest);
   app.route("/videoplayback", videoPlaybackProxy);
+  app.route("/metrics", metrics)
 };

src/routes/metrics.ts

@@ -0,0 +1,12 @@
+import { Hono } from "hono";
+import { register } from "./index.ts";
+
+const metrics = new Hono();
+  
+metrics.get("/", async () => {
+  return new Response(await register.metrics(), {
+    headers: { "Content-Type": "text/plain" },
+  });
+});
+
+export default metrics;

src/routes/youtube_api_routes/player.ts

@@ -3,9 +3,33 @@ import { youtubePlayerParsing } from "../../lib/helpers/youtubePlayerHandling.ts
 import { HonoVariables } from "../../lib/types/HonoVariables.ts";
 import { Innertube } from "youtubei.js";
 import { Store } from "@willsoto/node-konfig-core";
+import { reasonBot, subreasonProtectCommunity, videoRestricted, videoUnavailable } from "../index.ts";
 
 const player = new Hono<{ Variables: HonoVariables }>();
 
+const errors = [
+  {
+    // @ts-ignore: Property 'playabilityStatus' does not exist on type 'object'
+    check: (yt: object) => yt.playabilityStatus?.reason?.includes("Sign in to confirm you’re not a bot"),
+    action: () => reasonBot.inc(),
+  },
+  {
+    // @ts-ignore: Property 'playabilityStatus' does not exist on type 'object'
+    check: (yt: object) => yt.playabilityStatus?.errorScreen?.playerErrorMessageRenderer?.subreason?.runs?.[0]?.text?.includes("This helps protect our community"),
+    action: () => subreasonProtectCommunity.inc(),
+  },
+  {
+    // @ts-ignore: Property 'playabilityStatus' does not exist on type 'object'
+    check: (yt: object) => yt.playabilityStatus?.errorScreen?.playerErrorMessageRenderer?.subreason?.runs?.[0]?.text?.includes("Video unavailable"),
+    action: () => videoUnavailable.inc(),
+  },
+  {
+    // @ts-ignore: Property 'playabilityStatus' does not exist on type 'object'
+    check: (yt: object) => yt.playabilityStatus?.reason?.includes("This video is restricted"),
+    action: () => videoRestricted.inc(),
+  },
+];
+
 player.post("/player", async (c) => {
   const jsonReq = await c.req.json();
   const innertubeClient = await c.get("innertubeClient") as Innertube;
@@ -14,9 +38,13 @@ player.post("/player", async (c) => {
     Record<string, unknown>
   >;
   if (jsonReq.videoId) {
-    return c.json(
-      await youtubePlayerParsing(innertubeClient, jsonReq.videoId, konfigStore)
-    );
+    const yt = await youtubePlayerParsing(innertubeClient, jsonReq.videoId, konfigStore)
+    errors.forEach((error) => {
+      if (error.check(yt)) {
+        error.action()
+      }
+    })
+    return c.json(yt);
   }
 });