extracts size of S3 AWS Bucket from a list using cloudwatch

s3_buckets_size.sh

#!/bin/bash
# Execute as :
#   ./s3_buckets_size.sh list.txt
# where list.txt is a list of all bucket
for bucket in `cat $1`;do
  SIZE=$(aws cloudwatch get-metric-statistics --namespace AWS/S3 --start-time $(date +%Y-%m-%dT%H:%M:%S -d "00:00 last week") --end-time $(date +%Y-%m-%dT%H:%M:%S) --period 86400 --statistics Average --region eu-west-1 --metric-name BucketSizeBytes --dimensions Name=BucketName,Value=$bucket Name=StorageType,Value=StandardStorage | jq .Datapoints[].Average | tail -1)
  echo $bucketname $(numfmt --to iec --format "%8.1f" ${SIZE:-"0"})
done