feat: add upMetricName params to allow for up metric name customization

README.md

@@ -55,6 +55,7 @@ Which labels to include in `http_request_duration_seconds` metric:
 * **metricsPath**: replace the `/metrics` route with a **regex** or exact **string**. Note: it is highly recommended to just stick to the default
 * **metricType**: histogram/summary selection. See more details below
 * **httpDurationMetricName**: Allows you change the name of HTTP duration metric, default: **`http_request_duration_seconds`**.
+* **upMetricName**: Allows you change the name of up metric, default: **`up`**.
 
 ### metricType option ###
 

package-lock.json

@@ -6,7 +6,7 @@
   "packages": {
     "": {
       "name": "express-prom-bundle",
-      "version": "7.0.2",
+      "version": "8.0.0",
       "license": "MIT",
       "dependencies": {
         "@types/express": "^5.0.0",

src/index.js

@@ -91,6 +91,7 @@ function main(opts) {
   }
 
   const httpMetricName = opts.httpDurationMetricName || 'http_request_duration_seconds';
+  const upMetricName = opts.upMetricName || 'up';
 
   function makeHttpMetric() {
     const labels = ['status_code'];
@@ -138,7 +139,7 @@ function main(opts) {
       prefix = opts.promClient.collectDefaultMetrics.prefix || '';
     }
     metrics.up = new promClient.Gauge({
-      name: `${prefix}up`,
+      name: prefix + upMetricName,
       help: '1 = up, 0 = not up',
       registers: [opts.promRegistry]
     });

types/index.d.ts

@@ -38,6 +38,7 @@ declare namespace express_prom_bundle {
 
     metricsPath?: string;
     httpDurationMetricName?: string;
+    upMetricName?: string;
     promClient?: { collectDefaultMetrics?: DefaultMetricsCollectorConfiguration<RegistryContentType> };
     promRegistry?: Registry;
     normalizePath?: NormalizePathEntry[] | NormalizePathFn;