IAM 역할 및 정책

IAM policy: 권한 언어

{
  'Version': '2012-10-17',
  'Statement': [
    {
      'Effect': 'Allow',
      'Action': [
        's3:GetObject',
        's3:PutObject'
      ],
      'Resource': 'arn:aws:s3:::my-bucket/*'
    }
  ]
}

ID 기반 policy와 리소스 기반 policy

# Example S3 bucket policy (resource-based)
{
  'Version': '2012-10-17',
  'Statement': [{
    'Effect': 'Allow',
    'Principal': {
      'AWS': 'arn:aws:iam::123456789012:role/MyAppRole'
    },
    'Action': 's3:GetObject',
    'Resource': 'arn:aws:s3:::my-bucket/*'
  }]
}

IAM 역할: 임시 ID

# Attach an IAM role to an EC2 instance (instance profile)
aws ec2 associate-iam-instance-profile \
  --instance-id i-0abcdef1234567890 \
  --iam-instance-profile Name=MyEC2Role

신뢰 policy: 역할을 Assume할 수 있는 주체

# Trust policy for a Lambda execution role
{
  'Version': '2012-10-17',
  'Statement': [{
    'Effect': 'Allow',
    'Principal': {
      'Service': 'lambda.amazonaws.com'
    },
    'Action': 'sts:AssumeRole'
  }]
}

AWS 서비스 역할: EC2 및 Lambda

# Retrieve role credentials from EC2 metadata (IMDSv2)
TOKEN=$(curl -X PUT 'http://169.254.169.254/latest/api/token' \
  -H 'X-aws-ec2-metadata-token-ttl-seconds: 21600')
curl -H "X-aws-ec2-metadata-token: $TOKEN" \
  http://169.254.169.254/latest/meta-data/iam/security-credentials/MyEC2Role

교차 계정 역할 Assume

# Assume a cross-account role from Account A
aws sts assume-role \
  --role-arn arn:aws:iam::999999999999:role/CrossAccountRole \
  --role-session-name my-session

policy 조건: 세분화된 제어

# Policy that requires MFA for sensitive actions
{
  'Effect': 'Deny',
  'Action': ['iam:*', 'cloudtrail:*'],
  'Resource': '*',
  'Condition': {
    'BoolIfExists': {
      'aws:MultiFactorAuthPresent': 'false'
    }
  }
}

권한 경계

# Attach a permissions boundary to a user
aws iam put-user-permissions-boundary \
  --user-name alice \
  --permissions-boundary arn:aws:iam::aws:policy/AmazonS3ReadOnlyAccess

policy 평가 논리

IAM policy 시뮬레이터

# Simulate an IAM policy evaluation via CLI
aws iam simulate-principal-policy \
  --policy-source-arn arn:aws:iam::123456789012:user/alice \
  --action-names s3:PutObject \
  --resource-arns arn:aws:s3:::my-bucket/*

페더레이션 액세스용 역할

빠른 확인

단원 요약