Running on EC2

Install s3i first:

msiexec /i https://github.com/OlegBoulanov/s3i/releases/download/v1.0.306/s3i.msi

EC2 instance usually starts with a role assigned. To use that role in credentials, add these lines to profile:

[default]
role_arn = arn:aws:iam::<account-id>:role/<role-name>
credential_source = Ec2InstanceMetadata

More details can be found here

Also, corresponding security policy requires additional statement:

    {
        "Sid": "StsAssumeRole",
        "Effect": "Allow",
        "Action": [
            "sts:AssumeRole"
        ],
        "Resource": "arn:aws:iam::<account-id>:role/<role-name>"
    },