api: automatically pull youtube session tokens from a session server

if provided, cobalt will pull poToken & visitor_data from an instance of invidious' youtube-trusted-session-generator or its counterpart

api/src/processing/helpers/youtube-session.js

@@ -0,0 +1,74 @@
+import * as cluster from "../../misc/cluster.js";
+
+import { env } from "../../config.js";
+import { Green, Yellow } from "../../misc/console-text.js";
+
+let session;
+
+const validateSession = (sessionResponse) => {
+    if (!sessionResponse.potoken) {
+        throw "no poToken in session response";
+    }
+
+    if (!sessionResponse.visitor_data) {
+        throw "no visitor_data in session response";
+    }
+
+    if (!sessionResponse.updated) {
+        throw "no last update timestamp in session response";
+    }
+
+    // https://github.com/iv-org/youtube-trusted-session-generator/blob/c2dfe3f/potoken_generator/main.py#L25
+    if (sessionResponse.potoken.length < 160) {
+        console.error(`${Yellow('[!]')} poToken is too short and might not work (${new Date().toISOString()})`);
+    }
+}
+
+const updateSession = (newSession) => {
+    session = newSession;
+}
+
+const loadSession = async () => {
+    const sessionServerUrl = new URL(env.ytSessionServer);
+    sessionServerUrl.pathname = "/token";
+
+    const newSession = await fetch(sessionServerUrl).then(a => a.json());
+    validateSession(newSession);
+
+    if (!session || session.updated < newSession?.updated) {
+        cluster.broadcast({ youtube_session: newSession });
+        updateSession(newSession);
+    }
+}
+
+const wrapLoad = (initial = false) => {
+    loadSession()
+    .then(() => {
+        if (initial) {
+            console.log(`${Green('[✓]')} poToken & visitor_data loaded successfully!`);
+        }
+    })
+    .catch((e) => {
+        console.error(`${Yellow('[!]')} Failed loading poToken & visitor_data at ${new Date().toISOString()}.`);
+        console.error('Error:', e);
+    })
+}
+
+export const getYouTubeSession = () => {
+    return session;
+}
+
+export const setup = () => {
+    if (cluster.isPrimary) {
+        wrapLoad(true);
+        if (env.ytSessionReloadInterval > 0) {
+            setInterval(wrapLoad, env.ytSessionReloadInterval * 1000);
+        }
+    } else if (cluster.isWorker) {
+        process.on('message', (message) => {
+            if ('youtube_session' in message) {
+                updateSession(message.youtube_session);
+            }
+        });
+    }
+}

api/src/processing/services/youtube.js

@@ -4,6 +4,7 @@ import { fetch } from "undici";
 import { Innertube, Session } from "youtubei.js";
 
 import { env } from "../../config.js";
+import { getYouTubeSession } from "../helpers/youtube-session.js";
 import { getCookie, updateCookieValues } from "../cookie/manager.js";
 
 const PLAYER_REFRESH_PERIOD = 1000 * 60 * 15; // ms
@@ -70,16 +71,22 @@ const cloneInnertube = async (customFetch) => {
     const shouldRefreshPlayer = lastRefreshedAt + PLAYER_REFRESH_PERIOD < new Date();
 
     const rawCookie = getCookie('youtube');
-    const rawCookieValues = rawCookie?.values();
     const cookie = rawCookie?.toString();
 
+    const sessionTokens = getYouTubeSession();
+    const retrieve_player = Boolean(sessionTokens || cookie);
+
+    if (env.ytSessionServer && !sessionTokens?.potoken) {
+        throw "no_session_tokens";
+    }
+
     if (!innertube || shouldRefreshPlayer) {
         innertube = await Innertube.create({
             fetch: customFetch,
-            retrieve_player: !!cookie,
+            retrieve_player,
             cookie,
-            po_token: rawCookieValues?.po_token,
-            visitor_data: rawCookieValues?.visitor_data,
+            po_token: sessionTokens?.potoken,
+            visitor_data: sessionTokens?.visitor_data,
         });
         lastRefreshedAt = +new Date();
     }
@@ -135,7 +142,9 @@ export default async function (o) {
             })
         );
     } catch (e) {
-        if (e.message?.endsWith("decipher algorithm")) {
+        if (e === "no_session_tokens") {
+            return { error: "youtube.no_session_tokens" };
+        } else if (e.message?.endsWith("decipher algorithm")) {
             return { error: "youtube.decipher" }
         } else if (e.message?.includes("refresh access token")) {
             return { error: "youtube.token_expired" }