Using AWS X-Ray with Hapi.js

README.md

HapiJS with AWS XRay

A quick brain dump of where I'm at with getting Hapi and AWS Xray working

I'll might turn into a Hapi plugin at some point...

manifest.js

const { getListener } = require('./xray');

module.exports = {
  server: {
    host: '0.0.0.0',
    port: process.env.API_HTTP_PORT || 3000,
    listener: getListener(),
  },

  register: {
    plugins: [
      { plugin: './plugins/logs' },
      { plugin: './routes/api' },
      { plugin: './routes/core' }
    ]
  }
};

plugins_logs.js

const xray = require('../xray');
const log = require('../utils/log');

const debug = require('debug')('plugin:logs');

const register = (server, options) => {
  xray.setLogger(log);

  server.ext({
    type: 'onRequest',
    method: xray.getRequestHandler()
  });
};

exports.plugin = {
  register,
  name: 'logs',
  version: '0.1'
};

xray.js

const xray = require('aws-xray-sdk');

const pjson = require('../../package');

const http = xray.captureHTTPs(require('http'));
xray.captureAWS(require('aws-sdk'));
xray.capturePromise();

module.exports = {
  getListener: () => {
    return http.createServer();
  },

  setLogger: logger => {
    xray.setLogger(logger);
  },

  getRequestHandler: () => {
    xray.middleware.setDefaultName(pjson.name);

    return (request, h) => {
      const header = xray.middleware.processHeaders(request);
      const name = xray.middleware.resolveName(request.headers.host);
      const segment = new xray.Segment(name, header.Root, header.Parent);

      xray.middleware.resolveSampling(header, segment, {
        req: request.raw.req
      });

      segment.addIncomingRequestData(
        new xray.middleware.IncomingRequestData(request.raw.req)
      );

      xray.getLogger().debug(`Starting express segment: { 
        url: ${request.url}, 
        name: ${segment.name}, 
        trace_id: ${segment.trace_id},
        id: ${segment.id},
        sampled: ${!segment.notTraced}
      }`);

      request.server.events.on('response', req => {
        if (req.response.statusCode === 429) {
          segment.addThrottleFlag();
        }

        const cause = xray.utils.getCauseTypeFromHttpStatus(
          req.response.statusCode
        );

        if (cause) {
          segment[cause] = true;
        }

        if (request.response._error) {
          if (req.response.statusCode !== 404) {
            segment.addError(request.response._error);
          }
        }

        segment.http.close(request.response);
        segment.close();

        xray.getLogger().debug(`Closed express segment successfully: { 
          url: ${request.url},
          name: ${segment.name},
          trace_id: ${segment.trace_id},
          id: ${segment.id},
          sampled: ${!segment.notTraced}
        }`);
      });

      const ns = xray.getNamespace();
      ns.bindEmitter(request.raw.req);
      ns.bindEmitter(request.raw.res);

      ns.run(() => {
        xray.setSegment(segment);
      });

      return h.continue;
    };
  }
};