The simplest form of using the AWS CLI to create an S3 bucket is:
aws s3 mb s3://bucket-name
You can optionally specify the region:
aws s3 mb s3://bucket-name --region eu-west-1
If you don't specify the region, the default is us-east-1
(N. Virginia).
IAM
To be able to create buckets, you need an IAM role that has at least the following policy:
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "AllowCreateS3Bucket",
"Effect": "Allow",
"Action": [
"s3:CreateBucket"
],
"Resource": [
"arn:aws:s3:::*"
]
}
]
}