1. modify main.go with ak, sk, endpoint, bucket 和key

2. dd if=/dev/urandom of=/tmp/test1.txt bs=1M count=20
   dd if=/dev/urandom of=/tmp/test2.txt bs=1M count=30
   

   or others
3. install s3cmd add config .s3cfg
4. go build -o ./s3example ./main.go
5. bash retry.sh (in case multiple instances should be run in parallel add a objectname suffix arg, ex: bash retry.sh $$)