src/lib/routes/backstage.ts

import { writeHeapSnapshot } from 'v8';
import { tmpdir } from 'os';
import { join } from 'path';
import { register as prometheusRegister } from 'prom-client';
import Controller from './controller';
import type { IUnleashConfig } from '../types/option';

class BackstageController extends Controller {
    logger: any;

    constructor(config: IUnleashConfig) {
        super(config);

        this.logger = config.getLogger('backstage.js');

        if (config.server.serverMetrics) {
            this.get('/prometheus', async (req, res) => {
                res.set('Content-Type', prometheusRegister.contentType);
                res.end(await prometheusRegister.metrics());
            });
        }

        if (config.server.enableHeapSnapshotEnpoint) {
            this.get('/heap-snapshot', async (req, res) => {
                const fileName = join(
                    tmpdir(),
                    `unleash-${Date.now()}.heapsnapshot`,
                );
                writeHeapSnapshot(fileName);
                res.status(200);
                res.end('Snapshot written');
            });
        }
    }
}

export { BackstageController };