feature: specify headers in options

README.md

@@ -93,7 +93,9 @@ const config = {
   // Override used node-fetch
   fetch: undefined,
   // Additional labels to apply to each timeseries, i.e. [{ service: "SQS" }]
-  labels: undefined
+  labels: undefined,
+  // Additional HTTP headers to send with each request
+  headers: undefined
 };
 ```
 

index.js

@@ -1,5 +1,4 @@
 const SnappyJS = require("snappyjs");
-const fetch = require("node-fetch");
 const protobuf = require("protobufjs");
 const btoa = (s) => Buffer.from(s, "binary").toString("base64");
 const prom = require("./prom");
@@ -92,7 +91,7 @@ async function pushTimeseries(timeseries, options) {
 
   if (options?.url) {
     /** @type import("./types").MinimalFetch */
-    let fetch = options.fetch ||  require("node-fetch").default
+    let fetch = options.fetch || require("node-fetch").default;
     return fetch(options?.url, {
       method: "POST",
       headers: {
@@ -102,6 +101,7 @@ async function pushTimeseries(timeseries, options) {
               Authorization: "Basic " + btoa(options?.auth.username + ":" + options?.auth?.password),
             }
           : undefined),
+        ...(options.headers || {}),
       },
       body: SnappyJS.compress(buffer),
       timeout: options.timeout,
@@ -137,6 +137,13 @@ async function pushTimeseries(timeseries, options) {
   }
 }
 
+/**
+ * Sends metrics over HTTP(s)
+ *
+ * @param {Record<string,number>} metrics
+ * @param {import("./types").Options=} options
+ * @return {Promise<import("./types").Result>}
+ */
 async function pushMetrics(metrics, options) {
   return pushTimeseries(
     Object.entries(metrics).map((c) => ({

index.test.js

@@ -1,6 +1,6 @@
 const push = require("./index");
 
-push.pushMetrics({ users_total: 22}, { timeout: 1})
+push.pushMetrics({ users_total: 22 }, { timeout: 1 });
 
 const config = {
   url: process.env.GRAFANA_PUSH_URL,
@@ -43,7 +43,7 @@ for (let i = 0; i < 100; i++) {
         labels: {
           __name__: "test_exemplar_metric_total",
           instance: "localhost:8090",
-          job: "prometheus"
+          job: "prometheus",
         },
         samples: [
           {
@@ -59,4 +59,18 @@ for (let i = 0; i < 100; i++) {
     });
 }
 
-push.pushMetrics({ users_total: 11 })
+push.pushMetrics({ users_total: 11 });
+
+setTimeout(
+  () =>
+    push.pushMetrics(
+      { max_users_total: 31 },
+      {
+        headers: {
+          "X-extra-key": "test2",
+        },
+        verbose: true,
+      }
+    ),
+  1000
+);

package.json

@@ -1,6 +1,6 @@
 {
   "name": "prometheus-remote-write",
-  "version": "0.3.1",
+  "version": "0.4.0",
   "description": "Send samples to prometheus via remote_write from NodeJS",
   "main": "index.js",
   "types": "types.d.ts",

types.d.ts

@@ -40,6 +40,7 @@ interface Options {
   timeout?: number;
   console?: Console;
   fetch?: MinimalFetch;
+  headers?: { [key: string]: string };
 }
 
 interface Result {