Logging

logger.js

class Log {
  constructor(name, attributes = new Map()) {
    this.startTime = new Date().getTime();
    this.startTimestampMs = performance.now();
    this.name = name;
    this.attributes = attributes;
  }

  setAttributes(keyValues) {
    for (let [key, value] of Object.entries(keyValues)) {
      this.attributes.set(key, value);
    }
  }

  end() {
    this.elapsedMs = performance.now() - this.startTimestampMs;
  }
}

async function middleware(c, next) {
  // create a log entry before at the beginning of the request
  let log = new Log(`${c.req.method} ${c.req.path}`);

  // store information about the request, the more the better
  // this is just as an example
  log.setAttributes({
    "http.request.method": c.req.method,
    "http.request.path": c.req.path,
  });

  // make this available somehow during the request to the rest
  // of your code. For bonus points in Node use AsyncLocalStorage.
  // Have your handlers annotate lots of things: auth, user, route
  // feature flags.
  c.log = log;

  // Execute the request as normal
  await next();

  // pull any more info about the response
  log.setAttributes({
    "http.response.status_code": c.res.status,
  });
  // end the log
  log.end();

  // Turn it all to JSON and send it to an exporter function. Have it
  // periodically send off batched data to Honeycomb's events API. If
  // this is too much data have it send only a percentage of the logs
  // and drop the rest.
  exporter.export(log);
}