1. 创建一个IAM策略，命名为“terraform-policy”：

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "ec2:DescribeInstances",
                "ec2:DescribeRegions",
                "ec2:DescribeSecurityGroups",
                "ec2:DescribeSubnets",
                "ec2:DescribeVpcs",
                "ec2:DescribeKeyPairs",
                "ssh:Scan"
            ],
            "Resource": [
                "*"
            ]
        },
        {
            "Effect": "Allow",
            "Action": [
                "ec2:RunInstances",
                "ec2:TerminateInstances"
            ],
            "Resource": [
                "arn:aws:ec2:*:*:instance/*"
            ]
        }
    ]
}

2. 在IAM中创建一个新的用户，并将上述策略分配给该用户。

3. 使用AWS_ACCESS_KEY_ID和AWS_SECRET_ACCESS_KEY这两个环境变量或使用AWS CLI配置文件中的访问密钥和秘钥。具体操作方式和使用方法在AWS文档中有详细说明。