antongolub/npm-registry-firewall

import { getCtx } from '../als.js'
import { genId } from '../util.js'
import { once } from '../util.js'
import { logger } from '../logger.js'
import {pushMetric} from "../metric.js";

export const trace = async (req, res, next) => {
  req.id = res.id = genId()

  const ctx = getCtx()
  ctx.logExtra = Object.assign(ctx.logExtra || {}, {
    traceId: req.id,
    clientIp: req.headers['x-forwarded-for'] || req.socket.remoteAddress
  })

  logger.info(req.method, req.url)

  const end = res.end
  const startedAt = Date.now()
  // see http/client.js res.pipe(pipe.res, { end: true })
  res.end = once(function (...args) {
    const { statusCode } = res
    const isErr = statusCode < 200 || (statusCode >= 400 && statusCode !== 404)
    const delay  = Date.now() - startedAt

    if (req.timed) {
      pushMetric('response-time', delay)
    }
    logger[isErr ? 'error' : 'info']('HTTP', statusCode, `${delay}ms`, req.method, req.url)

    return end.call(this, ...args)
  })
  next()
}