aws s3 ls --summarize --human-readable --recursive s3://BUCKETNAME/PATH
or
aws s3 ls s3://BUCKETNAME/PATH --recursive | awk '{total+=$3} END{print "total =",total/1024/1024," MB"}'

aws cloudwatch get-metric-statistics --namespace AWS/S3 \
  --start-time 2018-02-05T00:00:00 --end-time 2018-02-06T00:00:00 \
  --period 86400 --statistics Average --region eu-west-1 --metric-name BucketSizeBytes \
  --dimensions Name=BucketName,Value=BUCKETNAME Name=StorageType,Value=StandardStorage \
  | jq -r '.Datapoints[0].Average' \
  | awk '{total+=$0} END{print "total =",int(total/1024/1024)," MB"}'

curl http://169.254.169.254/latest/user-data

bash <(curl http://169.254.169.254/latest/user-data)

tail -f /var/log/messages -n1000 | grep cloud-init

aws ec2 describe-instances --query 'Reservations[*].Instances[*].[InstanceId]' --region eu-west-3 --output text | wc -l

aws ec2 describe-instances \
  --output text \
  --query 'Reservations[*].Instances[*].[Tags[?Key==`Name`], PrivateIpAddress, PublicDnsName]' \
  --filters Name=tag:Name,Values='myprefix*' Name=instance-state-name,Values=running

aws sts get-caller-identity --output text --query 'Account'

aws rds describe-db-engine-versions --engine aurora-postgresql --query 'DBEngineVersions[?contains(SupportedEngineModes,`provisioned`)].EngineVersion'

aws ec2 describe-images \
    --owners 379101102735 \
    --filters 'Name=name,Values=debian-stretch*' 'Name=state,Values=available'

aws ec2 describe-security-groups \
  --output json \
  --query 'SecurityGroups[*].[GroupName, IpPermissions[*], IpPermissionsEgress[*]]' \
  --filters Name=tag:Name,Values='my-env*' > sgs_my-env.json