This assumes you have already configured the aws command line tool. If not, check out my article on Getting Started with the AWS CLI.

• An IAM Policy allows certain actions (such create) on certain resources (such as EC2)
• An IAM User is typically a users account (such as john.doe) that contains an IAM Identity-Based Policy that allows certain actions (such as list) on certain resources (such S3)
• An IAM Role contains an IAM Policy that allows certain actions (such create) on certain resources (such as EC2). Let's say the Identity-Based Policy attached to john.doe does NOT allow "create S3"
  • The Role that allows "create S3" could be attached to john.doe - or, john.doe could Assume the Role:
    • Assume Role or Switch Role using Python boto3
    • Assume Role or Switch Role using Terraform
    • Assume Role or Switch Role using the AWS CLI
  • Often, a Role will have two Policies:
    • Trust Relationship
    • Permission Policy

The aws iam create-instance-profile command can be used to create a new profile. In this example, a profile named my-profile will be created.

aws iam create-instance-profile --instance-profile-name my-profile

Often, then the aws iam add-role-to-instance-profile command is used to attach a role to the profile.

aws iam add-role-to-instance-profile --role-name my-role --instance-profile-name my-profile