S3 Bucket Size

s3-buckets-size.js

const AWS = require('aws-sdk')
const Promise = require('bluebird')
const filesize = require('filesize')

// AWS.config.update({ accessKeyId: '', secretAccessKey: '', region: '' })

const s3 = new AWS.S3()
const cloudwatch = new AWS.CloudWatch()
const TWELVE_HOURS_IN_SECONDS = 43_200

async function main() {
  try {
    const data = await s3.listBuckets().promise()
    const bucketNames = data.Buckets.map(bucket => bucket.Name)

    const sizes = await Promise.mapSeries(bucketNames, async bucketName => {
      try {
        // https://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/CloudWatch.html#getMetricStatistics-property
        const opts = {
          StartTime: new Date('2019-06-03T00:00:00'),
          EndTime: new Date('2019-06-13T00:00:00'),
          MetricName: 'BucketSizeBytes',
          Namespace: 'AWS/S3',
          Period: TWELVE_HOURS_IN_SECONDS,
          Dimensions: [
            { Name: 'BucketName', Value: bucketName },
            { Name: 'StorageType', Value: 'StandardStorage' },
          ],
          Statistics: ['Maximum'],
        }

        const stats = await cloudwatch.getMetricStatistics(opts).promise()
        const points = stats.Datapoints

        if (typeof points.pop() === 'undefined') {
          console.log(`${bucketName}: ${filesize(0)}`)
          return 0
        }

        console.log(`${bucketName}: ${filesize(points.pop().Maximum)}`)
        return points.pop().Maximum
      } catch (e) {
        console.log(e)
      }
    })

    console.log(filesize(sizes.reduce((acc, curr) => acc + curr)))
  } catch (e) {
    console.log(e)
  }
}

main() // run