Exporting traces via OTLP/HTTP in Deno

otel-deno.js

import opentelemetry from "npm:@opentelemetry/api";
import { context, trace } from "npm:@opentelemetry/api";
import {
  BasicTracerProvider,
  BatchSpanProcessor,
  ConsoleSpanExporter,
  SimpleSpanProcessor,
} from "npm:@opentelemetry/sdk-trace-base";
import { Resource } from "npm:@opentelemetry/resources";
import { OTLPTraceExporter } from "npm:@opentelemetry/exporter-trace-otlp-proto";
import { delay } from "https://deno.land/[email protected]/async/mod.ts";

const exporter = new OTLPTraceExporter({
  url: "http://localhost:4318/v1/traces", // url is optional and can be omitted - default is http://localhost:4318/v1/traces
  concurrencyLimit: 10, // an optional limit on pending requests
});

const provider = new BasicTracerProvider({
  resource: new Resource({
    ["service.name"]: "my-service",
  }),
});
provider.addSpanProcessor(
  new BatchSpanProcessor(exporter, {
    // The maximum queue size. After the size is reached spans are dropped.
    maxQueueSize: 1000,
    // The interval between two consecutive exports
    scheduledDelayMillis: 1000,
  }),
);
provider.addSpanProcessor(new SimpleSpanProcessor(new ConsoleSpanExporter()));
provider.register();

const tracer = opentelemetry.trace.getTracer("example-basic-tracer-node");

// Create a span. A span must be closed.
const parentSpan = tracer.startSpan("main");
for (let i = 0; i < 10; i += 1) {
  doWork(parentSpan);
}
// Be sure to end the span.
parentSpan.end();

function doWork(parent) {
  // Start another span. In this example, the main method already started a
  // span, so that'll be the parent span, and this will be a child span.
  const ctx = trace.setSpan(context.active(), parent);
  const span = tracer.startSpan("doWork", undefined, ctx);

  // simulate some random work.
  for (let i = 0; i <= Math.floor(Math.random() * 40000000); i += 1) {
    // empty
  }
  // Set attributes to the span.
  span.setAttribute("key", "value");

  span.setAttribute("mapAndArrayValue", [
    0,
    1,
    2.25,
    "otel",
    {
      foo: "bar",
      baz: "json",
      array: [1, 2, "boom"],
    },
  ]);

  // Annotate our span to capture metadata about our operation
  span.addEvent("invoking doWork");

  // end span
  span.end();
}

// give some time before it is closed
console.log("closing after 2s");
await delay(2000);
try {
  await exporter.shutdown();
} catch (e) {
  console.error(e);
}
console.log("closed");