elasticsearch.js

/*
 * Copyright Elasticsearch B.V. and other contributors where applicable.
 * Licensed under the BSD 2-Clause License; you may not use this file except in
 * compliance with the BSD 2-Clause License.
 */

'use strict';

const { URL, URLSearchParams } = require('url');

var shimmer = require('../shimmer');
var { getDBDestination } = require('../context');
const { getElasticsearchDbStatement } = require('../elasticsearch-shared');

const startsWithProtocolRE = /^([a-z]+:)?\/\//i;
const DEFAULT_PORT = 9200;
const DEFAULT_PORT_FROM_PROTO = {
  'http:': 80,
  'https:': 443,
};

// This is an imperfect equivalent of the handling in the `Transport`
// constructor and internal `Host` parsing function in the ES client.
// This returns a `URL` object or null.
function getTargetUrlFromTransportConfig(config) {
  const transportHosts = config ? config.host || config.hosts : null;
  if (!transportHosts) {
    return null;
  }

  let firstTransportHost = Array.isArray(transportHosts)
    ? transportHosts[0]
    : transportHosts;
  if (!firstTransportHost) {
    return null;
  }

  if (typeof firstTransportHost === 'string') {
    // "example.com:42" or "someprotocol://example.com:42" or
    // "someprotocol://example.com".
    if (!startsWithProtocolRE.test(firstTransportHost)) {
      firstTransportHost = 'http://' + firstTransportHost;
    }
    try {
      return new URL(firstTransportHost);
    } catch (_err) {
      return null;
    }
  } else if (typeof firstTransportHost === 'object') {
    let proto = firstTransportHost.protocol || 'http:';
    if (!proto.endsWith(':')) {
      proto += ':';
    }
    const hostname = firstTransportHost.hostname || firstTransportHost.host;
    const port = firstTransportHost.port || DEFAULT_PORT;
    try {
      return new URL(proto + '//' + hostname + ':' + port);
    } catch (_ignoredErr) {
      return null;
    }
  }

  return null;
}

module.exports = function (elasticsearch, agent, { enabled }) {
  if (!enabled) return elasticsearch;

  const ins = agent._instrumentation;
  const elasticsearchCaptureBodyUrlsRegExp =
    agent._conf.elasticsearchCaptureBodyUrlsRegExp;

  agent.logger.debug('shimming elasticsearch.Transport.prototype.request');
  shimmer.wrap(
    elasticsearch.Transport && elasticsearch.Transport.prototype,
    'request',
    wrapRequest,
  );

  return elasticsearch;

  function wrapRequest(original) {
    return function wrappedRequest(params, cb) {
      var span = ins.createSpan(null, 'db', 'elasticsearch', 'request', {
        exitSpan: true,
      });
      var id = span && span.transaction.id;
      var method = params && params.method;
      var path = params && params.path;

      agent.logger.debug(
        'intercepted call to elasticsearch.Transport.prototype.request %o',
        { id, method, path },
      );

      if (span && method && path) {
        span.name = `Elasticsearch: ${method} ${path}`;

        // Set DB context.
        const dbContext = {
          type: 'elasticsearch',
        };
        const statement = getElasticsearchDbStatement(
          path,
          params && params.body,
          elasticsearchCaptureBodyUrlsRegExp,
        );
        if (statement) {
          dbContext.statement = statement;
        }
        span.setDbContext(dbContext);

        // Get the remote host information from elasticsearch Transport options.
        const targetUrl = getTargetUrlFromTransportConfig(this._config);
        let port = targetUrl && targetUrl.port;
        if (!port && targetUrl) {
          port = DEFAULT_PORT_FROM_PROTO[targetUrl.protocol];
        }
        span._setDestinationContext(
          getDBDestination(targetUrl && targetUrl.hostname, port),
        );
        if (targetUrl) {
          targetUrl.pathname = path;
          targetUrl.search = new URLSearchParams(params.query).toString();
          span.setHttpContext({
            url: targetUrl.toString(),
          });
        }

        const parentRunContext = ins.currRunContext();
        const spanRunContext = parentRunContext.enterSpan(span);
        if (typeof cb === 'function') {
          var args = Array.prototype.slice.call(arguments);
          args[1] = function () {
            span.end();
            ins.withRunContext(parentRunContext, cb, this, ...arguments);
          };
          return ins.withRunContext(spanRunContext, original, this, ...args);
        } else {
          const originalPromise = ins.withRunContext(
            spanRunContext,
            original,
            this,
            ...arguments,
          );

          const descriptors = Object.getOwnPropertyDescriptors(originalPromise);
          delete descriptors.domain;

          const inspectedPromise = originalPromise.then(
            function (value) {
              span.end();
              return value;
            },
            function (err) {
              span.end();
              throw err;
            },
          );

          Object.defineProperties(inspectedPromise, descriptors);

          // we have to properly end the span when user aborts the request
          shimmer.wrap(
            inspectedPromise,
            'abort',
            function wrapAbort(originalAbort) {
              return function wrappedAbort() {
                if (span.ended) return;
                agent.logger.debug(
                  'intercepted call to elasticsearch.Transport.request.abort %o',
                  { id, method, path },
                );
                const originalReturn = originalAbort.apply(this, args);
                span.end();
                return originalReturn;
              };
            },
          );

          return inspectedPromise;
        }
      } else {
        agent.logger.debug('could not instrument elasticsearch request %o', {
          id,
        });
        return original.apply(this, arguments);
      }
    };
  }
};