From c4be86b6514219b60caa5cf271efac0ea103567d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Asbj=C3=B8rn=20Dyhrberg=20Thegler?= <asbjoern@thegler.dk>
Date: Fri, 17 Jun 2022 13:41:36 +0200
Subject: [PATCH] Add metricsApp option

Lets you supply an additional express app on which to mount the metrics
endpoint
---
 src/index.js | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/index.js b/src/index.js
index 6f85193..cc6969e 100644
--- a/src/index.js
+++ b/src/index.js
@@ -68,7 +68,8 @@ function main(opts) {
       formatStatusCode: main.normalizeStatusCode,
       metricType: 'histogram',
       promClient: {},
-      promRegistry: promClient.register
+      promRegistry: promClient.register,
+      metricsApp: null,
     }, opts
   );
 
@@ -204,6 +205,13 @@ function main(opts) {
     next();
   };
 
+  if (opts.metricsApp) {
+    opts.metricsApp.get(opts.metricsPath || '/metrics', async (req, res, next) => {
+      res.set('Content-Type', opts.promRegistry.contentType);
+      return res.end(await opts.promRegistry.metrics());
+    });
+  }
+
   middleware.metrics = metrics;
   middleware.promClient = promClient;
   middleware.metricsMiddleware = metricsMiddleware;