66 lines
2.0 KiB
JavaScript
66 lines
2.0 KiB
JavaScript
'use strict';
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const { DiagConsoleLogger, DiagLogLevel, diag } = require('@opentelemetry/api');
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const { MeterProvider } = require('@opentelemetry/sdk-metrics');
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const { PrometheusExporter } = require('@opentelemetry/exporter-prometheus');
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// Optional and only needed to see the internal diagnostic logging (during development)
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diag.setLogger(new DiagConsoleLogger(), DiagLogLevel.DEBUG);
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const { endpoint, port } = PrometheusExporter.DEFAULT_OPTIONS;
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const exporter = new PrometheusExporter({}, () => {
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console.log(
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`prometheus scrape endpoint: http://localhost:${port}${endpoint}`,
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);
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});
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// Creates MeterProvider and installs the exporter as a MetricReader
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const meterProvider = new MeterProvider({
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readers: [exporter],
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});
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const meter = meterProvider.getMeter('example-prometheus');
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// Creates metric instruments
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const requestCounter = meter.createCounter('requests', {
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description: 'Example of a Counter',
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});
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const upDownCounter = meter.createUpDownCounter('test_up_down_counter', {
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description: 'Example of a UpDownCounter',
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});
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const attributes = { pid: process.pid, environment: 'staging' };
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let counter = 0;
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const observableCounter = meter.createObservableCounter('observable_requests', {
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description: 'Example of an ObservableCounter',
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});
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observableCounter.addCallback(observableResult => {
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observableResult.observe(counter, attributes);
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});
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const randomMetricPromise = async () =>
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new Promise(resolve =>
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setTimeout(resolve(Math.floor(Math.random() * 100)), 50)
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);
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const observableGauge = meter.createObservableGauge(
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'observable_gauge_requests',
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{
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description: 'Example of an ObservableGauge',
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}
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);
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// Callbacks are run when metrics are scraped
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observableGauge.addCallback(async observableResult => {
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const value = await randomMetricPromise();
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observableResult.observe(value, attributes);
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});
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// Record metrics
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setInterval(() => {
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counter++;
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requestCounter.add(1, attributes);
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upDownCounter.add(Math.random() > 0.5 ? 1 : -1, attributes);
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}, 1000);
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