You can't install awscli on CoreOS, so you have to use this container to run it.
$ docker build -t quipper/awscli .
You have to attache IAM role on your EC2 instance to run this:
$ docker run -it quipper/awscli <command> <args>
List Buckets
$ docker run -it quipper/awscli aws s3 ls
Content type
Image
Digest
Size
25.6 MB
Last updated
about 10 years ago
docker pull quipper/awscli