get the estimated storage size of AWS buckets without listing all the objects

get_s3_estimated_size.sh

bucket_name=$1
[ -z "$bucket_name" ] && echo "usage: $0 bucket_name" && exit 1

start_time=`date +'%FT%T' -d '-3 days'`
end_time=`date +'%FT%T'`

aws cloudwatch --region cn-north-1 \
    get-metric-statistics \
    --namespace AWS/S3 \
    --metric-name BucketSizeBytes \
    --start-time $start_time \
    --end-time $end_time \
    --period 86400 \
    --statistics Average \
    --dimensions Name=BucketName,Value=$bucket_name\
    Name=StorageType,Value=StandardStorage