Release 10/6 (#6)

* add metrics to track upload times

Dockerfile

@@ -1,4 +1,4 @@
-FROM node:20-alpine AS base
+FROM node:19-alpine AS base
 WORKDIR /app
 ENV HOME=/app
 RUN addgroup -g 10000 uploader && adduser -u 10000 -G uploader -s /bin/sh -D uploader

metrics.js

@@ -0,0 +1,36 @@
+import { MeterProvider } from "@opentelemetry/sdk-metrics";
+import { PrometheusExporter } from "@opentelemetry/exporter-prometheus";
+
+// Define a configuration object to organize configuration values
+const config = {
+  port: 9464,
+  meterName: "hub-uploads",
+  histogramConfig: {
+    name: "hub_uploads_upload_time_milliseconds",
+    description: "Time in milliseconds for a file upload",
+    unit: "ms",
+    boundaries: [100, 200, 400, 800, 1600],
+    labelKeys: ["status"],
+  },
+};
+
+// Export a Metrics object to encapsulate initialization and the exporter
+const Metrics = {
+  exporter: new PrometheusExporter({ port: config.port }),
+
+  initialize() {
+    const meterProvider = new MeterProvider();
+    meterProvider.addMetricReader(this.exporter);
+    const meter = meterProvider.getMeter(config.meterName);
+
+    const FileUploadTime = meter.createHistogram(config.histogramConfig.name, {
+      description: config.histogramConfig.description,
+      unit: config.histogramConfig.unit,
+      boundaries: config.histogramConfig.boundaries,
+    });
+
+    return { meter, FileUploadTime };
+  },
+};
+
+export default Metrics;