prom: export metrics

packages/prom-client/handler.ts

@@ -0,0 +1,52 @@
+import { AggregatorRegistry, metric } from 'prom-client';
+import * as system from 'hydrooj/src/model/system';
+import * as bus from 'hydrooj/src/service/bus';
+import { Handler, Route } from 'hydrooj/src/service/server';
+import { registry } from './metrics';
+
+declare module 'hydrooj/src/service/bus' {
+    interface EventMap {
+        metrics: (id: string, metrics: any) => void;
+    }
+}
+declare module 'hydrooj/src/interface' {
+    interface SystemKeys {
+        'prom-client.name': string;
+        'prom-client.password': string;
+        'prom-client.collect_rate': number;
+    }
+}
+
+const instances: Record<string, metric[]> = {};
+
+class MetricsHandler extends Handler {
+    noCheckPermView = true;
+    notUsage = true;
+
+    async get() {
+        if (!this.request.headers.authorization) {
+            this.response.status = 401;
+            this.response.body = {};
+            this.response.addHeader('WWW-Authenticate', 'Basic');
+            return;
+        }
+        const [name, password] = system.getMany(['prom-client.name', 'prom-client.password']);
+        const key = this.request.headers.authorization?.split('Basic ')?.[1];
+        if (!key || key !== Buffer.from(`${name}:${password}`).toString('base64')) {
+            this.response.status = 403;
+            this.response.body = {};
+            return;
+        }
+        this.response.body = await AggregatorRegistry.aggregate(Object.values(instances)).metrics();
+        this.response.type = 'text/plain';
+    }
+}
+
+bus.on('metrics', (id, metrics) => { instances[id] = metrics; });
+setInterval(async () => {
+    bus.broadcast('metrics', process.env.NODE_APP_INSTANCE!, await registry.getMetricsAsJSON());
+}, 5000 * (+system.get('prom-client.collect_rate') || 1));
+
+global.Hydro.handler.prom = () => {
+    Route('metrics', '/metrics', MetricsHandler);
+};