get cloudwatch logs

cloudwatchlogs.js

const _ = require('lodash');
const AWS = require('aws-sdk');
const retry = require('bluebird-retry');

function recursiveReq(request, params, key, items = [], count = 0) {
  return request(params).then(data => {
    const newItems = items.concat(data[key]);
    const lastItem = _.last(newItems);
    const nextToken = _.get(data, 'nextToken', null);

    if (data.events.length !== 0) {
      let lastDate;
      // update lastDate 
      data.events.forEach(event => {
        let parsedTimestamp = new Date(event.timestamp);

        if (lastDate === undefined || lastDate < parsedTimestamp) {
          lastDate = parsedTimestamp;
        }
      });
      params.startTime = lastDate.getTime();
    }

    if (nextToken) {
      const newParams = _.merge({}, params, {
        nextToken,
      });
      return recursiveReq(request, newParams, key, newItems, ++count);
    }
    console.info(
      `[recursiveReq] Key: ${key}, Items: ${newItems.length}, Count: ${count}`
    );
    return {events: newItems, lastItem, nextToken};
  });
}

const retryConfig = {
  interval: 1000,
  backoff: 2,
  throw_original: true,
  max_tries: 5,
  max_interval: 10000,
};

const cloudwatchlogs = ({
  start = new Date().getTime() - 60 * 1000 * 120,
  end = new Date().getTime(),
  nextToken,
  name,
  filter,
  limit = 100,
  region = 'us-west-2',
}) => {
  let params = {
    logGroupName: name,
    limit,
    nextToken,
    filterPattern: filter,
    // interleaved: true, // mix multiple log streams
  };

  if (start) {
    params.startTime = start;
  }
  if (end) {
    params.endTime = end;
  }

  const options = {};
  options.region = region;
  const log = new AWS.CloudWatchLogs(options);

  const getLogs = params => {
    return log.filterLogEvents(params).promise().catch(err => {
      console.error('[CloudWatchLogs] Error fetching logs', err);
      return Promise.reject(err);
    });
  };

  return recursiveReq(getLogs, params, 'events');
};

module.exports = cloudwatchlogs;