feat: prometheus metrics (#1033)

package.json

@@ -60,6 +60,7 @@
 			"@types/bson": "1.0.11",
 			"@types/node": "18.11.18",
 			"@types/express-serve-static-core": "4.17.29",
+			"@types/express": "4.17.13",
 			"ts-node": "10.9.1",
 			"mongodb": "3.6.3"
 		},

pnpm-lock.yaml

@@ -9,6 +9,7 @@ overrides:
   '@types/bson': 1.0.11
   '@types/node': 18.11.18
   '@types/express-serve-static-core': 4.17.29
+  '@types/express': 4.17.13
   ts-node: 10.9.1
   mongodb: 3.6.3
 
@@ -576,6 +577,9 @@ importers:
       express-async-errors:
         specifier: 3.1.1
         version: 3.1.1(express@4.18.2)
+      express-prom-bundle:
+        specifier: ^7.0.0
+        version: 7.0.0(prom-client@15.1.1)
       express-rate-limit:
         specifier: 5.5.1
         version: 5.5.1
@@ -3127,6 +3131,11 @@ packages:
       aggregate-error: 3.1.0
     dev: false
 
+  /@opentelemetry/api@1.8.0:
+    resolution: {integrity: sha512-I/s6F7yKUDdtMsoBWXJe8Qz40Tui5vsuKCWJEWVL+5q9sSWRzzx6v2KeNsOBEwd94j0eWkpWCH4yB6rZg9Mf0w==}
+    engines: {node: '>=8.0.0'}
+    dev: false
+
   /@popperjs/core@2.11.6:
     resolution: {integrity: sha512-50/17A98tWUfQ176raKiOGXuYpLyyVMkxxG6oylzL3BPOlA6ADGdK7EYunSa4I064xerltq9TGXs8HmOk5E+vw==}
     dev: false
@@ -4156,6 +4165,10 @@ packages:
       file-uri-to-path: 1.0.0
     dev: false
 
+  /bintrees@1.0.2:
+    resolution: {integrity: sha512-VOMgTMwjAaUG580SXn3LacVgjurrbMme7ZZNYGSSV7mmtY6QQRh0Eg3pwIcntQ77DErK1L0NxkbetjcoXzVwKw==}
+    dev: false
+
   /bl@2.2.1:
     resolution: {integrity: sha512-6Pesp1w0DEX1N550i/uGV/TqucVL4AM/pgThFSN/Qq9si1/DF9aIHs1BxD8V/QU0HoeHO6cQRTAuYnLPKq1e4g==}
     dependencies:
@@ -5959,6 +5972,21 @@ packages:
       express: 4.18.2
     dev: false
 
+  /express-prom-bundle@7.0.0(prom-client@15.1.1):
+    resolution: {integrity: sha512-VwVaCyGBGHkHdecpTqRdW1Jm2fXK8weCUKjGjNWorc9g4M+cZ3xoj+N9uQzfRWfIPXJG5QOaiAziOIalQzMwgA==}
+    engines: {node: '>=18'}
+    peerDependencies:
+      prom-client: '>=15.0.0'
+    dependencies:
+      '@types/express': 4.17.13
+      express: 4.18.2
+      on-finished: 2.4.1
+      prom-client: 15.1.1
+      url-value-parser: 2.2.0
+    transitivePeerDependencies:
+      - supports-color
+    dev: false
+
   /express-rate-limit@5.5.1:
     resolution: {integrity: sha512-MTjE2eIbHv5DyfuFz4zLYWxpqVhEhkTiwFGuB74Q9CSou2WHO52nlE5y3Zlg6SIsiYUIPj6ifFxnkPz6O3sIUg==}
     dev: false
@@ -8771,6 +8799,14 @@ packages:
       fromentries: 1.3.2
     dev: true
 
+  /prom-client@15.1.1:
+    resolution: {integrity: sha512-GVA2H96QCg2q71rjc3VYvSrVG7OpnJxyryC7dMzvfJfpJJHzQVwF3TJLfHzKORcwJpElWs1TwXLthlJAFJxq2A==}
+    engines: {node: ^16 || ^18 || >=20}
+    dependencies:
+      '@opentelemetry/api': 1.8.0
+      tdigest: 0.1.2
+    dev: false
+
   /promise@7.3.1:
     resolution: {integrity: sha512-nolQXZ/4L+bP/UGlkfaIujX9BKxGwmQ9OT4mOt5yvy8iK1h3wqTEJCijzGANTCCl9nWjY41juyAn2K3Q1hLLTg==}
     dependencies:
@@ -10264,6 +10300,12 @@ packages:
       diff: 4.0.2
     dev: true
 
+  /tdigest@0.1.2:
+    resolution: {integrity: sha512-+G0LLgjjo9BZX2MfdvPfH+MKLCrxlXSYec5DaPYP1fe6Iyhf0/fSmJ0bFiZ1F8BT6cGXl2LpltQptzjXKWEkKA==}
+    dependencies:
+      bintrees: 1.0.2
+    dev: false
+
   /terser@5.16.1:
     resolution: {integrity: sha512-xvQfyfA1ayT0qdK47zskQgRZeWLoOQ8JQ6mIgRGVNwZKdQMU+5FkCBjmv4QjcrTzyZquRw2FVtlJSRUmMKQslw==}
     engines: {node: '>=10'}
@@ -10675,6 +10717,11 @@ packages:
     resolution: {integrity: sha512-mYFmBHCapZjtcNHW0MDq9967t+z4Dmg5CJ0KqysK3+ZbyoNOWQHksGCTWwDhxGXllkWlOc10Xfko6v4a3ucM6A==}
     dev: false
 
+  /url-value-parser@2.2.0:
+    resolution: {integrity: sha512-yIQdxJpgkPamPPAPuGdS7Q548rLhny42tg8d4vyTNzFqvOnwqrgHXvgehT09U7fwrzxi3RxCiXjoNUNnNOlQ8A==}
+    engines: {node: '>=6.0.0'}
+    dev: false
+
   /use-isomorphic-layout-effect@1.1.2(@types/react@17.0.13)(react@17.0.2):
     resolution: {integrity: sha512-49L8yCO3iGT/ZF9QttjwLF/ZD9Iwto5LnH5LmEdk/6cFmXddqi2ulF0edxTwjj+7mqvpVVGQWvbXZdn32wRSHA==}
     peerDependencies:

server/package.json

@@ -72,6 +72,7 @@
 		"dotenv": "16.0.0",
 		"express": "4.18.2",
 		"express-async-errors": "3.1.1",
+		"express-prom-bundle": "^7.0.0",
 		"express-rate-limit": "5.5.1",
 		"express-session": "1.17.2",
 		"fast-json-stable-hash": "1.0.3",

server/src/lib/setup/config.ts

@@ -83,6 +83,7 @@ export interface TachiServerConfig {
 	OPTIONS_ALWAYS_SUCCEEDS?: boolean;
 	USE_EXTERNAL_SCORE_IMPORT_WORKER: boolean;
 	EXTERNAL_SCORE_IMPORT_WORKER_CONCURRENCY?: integer;
+	ENABLE_METRICS: boolean;
 	SEEDS_CONFIG?: {
 		REPO_URL: string;
 		USER_NAME: string | null;
@@ -176,6 +177,7 @@ const err = p(config, {
 	USE_EXTERNAL_SCORE_IMPORT_WORKER: "*boolean",
 	EXTERNAL_SCORE_IMPORT_WORKER_CONCURRENCY: p.optional(p.isPositiveInteger),
 	ALLOW_RUNNING_OFFLINE: "*boolean",
+	ENABLE_METRICS: "*boolean",
 	EMAIL_CONFIG: p.optional({
 		FROM: "string",
 		DKIM: "*object",
@@ -273,6 +275,7 @@ tachiServerConfig.MAX_RIVALS ??= 5;
 tachiServerConfig.MAX_FOLLOWING_AMOUNT ??= 1_000;
 tachiServerConfig.USE_EXTERNAL_SCORE_IMPORT_WORKER ??= false;
 tachiServerConfig.TACHI_CONFIG.SIGNUPS_ENABLED ??= true;
+tachiServerConfig.ENABLE_METRICS ??= false;
 
 export const TachiConfig = tachiServerConfig.TACHI_CONFIG;
 export const ServerConfig = tachiServerConfig;

server/src/server/server.ts

@@ -7,6 +7,7 @@ import "express-async-errors";
 import { RequestLoggerMiddleware } from "./middleware/request-logger";
 import mainRouter from "./router/router";
 import connectRedis from "connect-redis";
+import ExpressPromBundle from "express-prom-bundle";
 import expressSession from "express-session";
 import { RedisClient } from "external/redis/redis";
 import helmet from "helmet";
@@ -84,6 +85,10 @@ if (Environment.nodeEnv !== "production" && IsNonEmptyString(ServerConfig.CLIENT
 		next();
 	});
 
+	if (ServerConfig.ENABLE_METRICS) {
+		app.use(ExpressPromBundle({ includeMethod: true, includePath: true }));
+	}
+
 	// hack to allow all OPTIONS requests. Remember that this setting should not be on in production!
 	if (ServerConfig.OPTIONS_ALWAYS_SUCCEEDS === true) {
 		app.options("*", (req, res) => res.send());