43 lines
1.3 KiB
TypeScript
43 lines
1.3 KiB
TypeScript
import type { Plugin } from 'vite';
|
||
|
||
/**
|
||
* Vite plugin that exposes a /metrics endpoint during development.
|
||
*
|
||
* The endpoint returns Prometheus‑text metrics collected in
|
||
* src/lib/telemetry.ts.
|
||
*/
|
||
export function metricsPlugin(): Plugin {
|
||
let telemetryModule: typeof import('./src/lib/telemetry') | null = null;
|
||
|
||
return {
|
||
name: 'zeavis-metrics',
|
||
|
||
configureServer(server) {
|
||
server.middlewares.use(async (req, res, next) => {
|
||
// Only handle GET /metrics
|
||
if (req.method !== 'GET' || !req.url?.startsWith('/metrics')) {
|
||
return next();
|
||
}
|
||
|
||
// Lazy‑load the telemetry module (ensures the app is bootstrapped first)
|
||
if (!telemetryModule) {
|
||
try {
|
||
telemetryModule = await server.ssrLoadModule('./src/lib/telemetry.ts') as typeof import('./src/lib/telemetry');
|
||
} catch {
|
||
// If the module isn't ready yet, return an empty body
|
||
res.statusCode = 200;
|
||
res.setHeader('Content-Type', 'text/plain; charset=utf-8');
|
||
res.end('# telemetry module not yet loaded\n');
|
||
return;
|
||
}
|
||
}
|
||
|
||
const body = telemetryModule.collectMetrics();
|
||
res.statusCode = 200;
|
||
res.setHeader('Content-Type', 'text/plain; charset=utf-8');
|
||
res.end(body);
|
||
});
|
||
},
|
||
};
|
||
}
|