STEP-1
Create Admin role through this Instance profile - cloud formation template.
Go to Cloud formation → upload.
STEP-2
Create EC2 instance and attach above admin role i.e.
Go to EC2 → identify EC2 instance → actions → attach S3 role.
STEP-3
Login to above EC2 instance, and create IAM User.
$ aws iam create-user --user-name s34jira
STEP-4
Attach User policy
$ aws iam attach-user-policy --user-name s34jira --policy-arn arn:aws:iam::aws:policy/AmazonS3FullAccess
STEP-5
Create Access keys
$ aws iam create-access-key --user-name s34jira