Concepts
Access controls and management across multiple accounts are crucial in the AWS ecosystem, especially for organizations that require strict compliance, security, and governance. When preparing for the AWS Certified Solutions Architect – Associate (SAA-C03) exam, understanding these concepts is key to designing and implementing scalable and secure systems on AWS.
Identity and Access Management (IAM)
At the core of AWS access controls is AWS Identity and Access Management (IAM). IAM allows you to manage users, groups, roles, and permissions. To streamline access across multiple accounts within an organization, AWS recommends using IAM roles and AWS Organizations.
IAM Roles for Cross-Account Access
IAM roles enable you to delegate access with defined permissions to users, applications, or services without having to share security credentials. For example, assume your company has two AWS accounts – DevAccount and ProdAccount. You could create an IAM role in ProdAccount that defines what actions are permissible, and then grant users in DevAccount the ability to assume that role.
Here’s a basic example policy that grants a user in DevAccount the ability to assume a role in ProdAccount:
{
“Version”: “2012-10-17”,
“Statement”: [
{
“Effect”: “Allow”,
“Action”: “sts:AssumeRole”,
“Resource”: “arn:aws:iam::ProdAccountID:role/ProdAccessRole”
}
]
}
AWS Organizations for Multi-Account Management
AWS Organizations helps you centrally manage and govern your environment as you grow and scale your AWS resources. Using AWS Organizations, you can create groups of accounts, apply policies to these groups, and automate account creation and management. This service is integral for managing access at the account level.
Service Control Policies
Within AWS Organizations, Service Control Policies (SCPs) offer central control over permissions for all accounts in your organization. SCPs help to ensure that accounts adhere to compliance requirements by uniformly limiting permissions across your AWS environment. For instance, you might prevent all users from disabling CloudTrail logging across all accounts.
Here’s an example SCP that denies disabling CloudTrail:
{
“Version”: “2012-10-17”,
“Statement”: [
{
“Effect”: “Deny”,
“Action”: “cloudtrail:StopLogging”,
“Resource”: “*”
}
]
}
Resource Access Manager (RAM)
For sharing resources across accounts within your organization, AWS Resource Access Manager (RAM) allows you to share AWS resources like Subnets, Transit Gateways, or License configurations. This avoids the need to create duplicate resources in each account, saving costs and administrative effort.
Centralized Logging and Monitoring
Centralized logging and monitoring are pivotal for managing multiple accounts. Forwarding logs to a central account helps in aggregating logs and analyzing data using services like CloudWatch and Athena. For example, you could set up CloudTrail to deliver logs to a central S3 bucket and then use CloudWatch Logs to trigger alarms or automate responses to events.
Simplified Billing
AWS provides consolidated billing through AWS Organizations, which allows you to combine billing and payment for multiple AWS accounts. This simplifies account administration, enables volume discounts, and provides a single bill for the entire organization.
Comparison of Access Control Options
| Feature | IAM Roles | AWS Organizations and SCPs | AWS RAM | Centralized Logging |
|---|---|---|---|---|
| Purpose | Delegate access | Governance and compliance | Resource sharing | Monitoring and auditing |
| Use Case | Accessing resources in other accounts | Enforcing policies across accounts | Sharing subnets, transit gateways, etc. | Centralized view of logs and alerts |
| Granularity | Per user, group, or service | Applied to Org units or entire organization | Shared resource level | Account level |
| Flexibility | High – can tailor policies per role | High – can tailor SCPs per Org unit | Moderate – depends on the shareable resource types | High – configure as per requirements |
Understanding these various access control and management options is essential for successfully passing the AWS Certified Solutions Architect – Associate exam. During your preparation, consider how these services and features can be utilized to design secure, cost-effective, and efficient architectures for managing resources across multiple AWS accounts.
Answer the Questions in Comment Section
True or False: AWS IAM roles can be used to delegate permissions to an AWS service to act on your behalf.
- A) True
- B) False
Answer: A) True
Explanation: AWS IAM roles can indeed be used to delegate permissions to an AWS service or other entity to perform actions in your AWS account.
Which of the following services allows you to manage access across multiple AWS accounts using roles?
- A) AWS IAM
- B) AWS Security Hub
- C) AWS Config
- D) Amazon Cognito
Answer: A) AWS IAM
Explanation: AWS Identity and Access Management (IAM) allows the management of users, groups, and roles and the permissions for those entities across multiple AWS accounts.
True or False: AWS Organizations helps in centrally managing billing; control access, compliance, and security; and share resources across your AWS accounts.
- A) True
- B) False
Answer: A) True
Explanation: AWS Organizations helps in consolidating multiple AWS accounts, allowing centralized billing and management of policies that apply across all accounts in the organization.
Which AWS service can you use to centrally manage policies across multiple AWS accounts?
- A) AWS IAM
- B) AWS SSO (Single Sign-On)
- C) AWS Organizations
- D) AWS Shield
Answer: C) AWS Organizations
Explanation: AWS Organizations allows the central management of policies and can be used to apply service control policies across multiple AWS accounts.
True or False: Cross-account access in AWS cannot be set up to allow users from one AWS account to access resources in another.
- A) True
- B) False
Answer: B) False
Explanation: Cross-account access can be configured in AWS using IAM roles and resource-based policies, thus allowing users from one AWS account to access resources in another.
What feature of AWS Organizations provides a way to apply permissions across multiple accounts?
- A) IAM Policies
- B) Service Control Policies (SCPs)
- C) Access Control Lists (ACLs)
- D) AWS Shield
Answer: B) Service Control Policies (SCPs)
Explanation: Service Control Policies (SCPs) are part of AWS Organizations and offer central control over the maximum available permissions for all accounts in your organization.
Which of the following AWS services allows you to use existing on-premises corporate identities to access AWS services across multiple accounts?
- A) AWS IAM
- B) Amazon Cognito
- C) AWS Directory Service
- D) AWS SSO (Single Sign-On)
Answer: D) AWS SSO (Single Sign-On)
Explanation: AWS SSO (Single Sign-On) allows integration with on-premises corporate directories, like Microsoft Active Directory, enabling users to access AWS services across all accounts in an AWS Organization.
True or False: When an IAM user leaves an organization, the IAM user’s access to all the AWS accounts under AWS Organizations is automatically revoked.
- A) True
- B) False
Answer: B) False
Explanation: While AWS Organizations provide central management, IAM users are managed individually within each AWS account. User access must be revoked manually from each account unless centralized identity services or automated processes are in place.
Multiple Select: Which combination of policies defines the effective permissions for an IAM user?
- A) User Policy
- B) Group Policy
- C) Resource Policy
- D) Organization SCPs
Answer: A) User Policy, B) Group Policy, C) Resource Policy, D) Organization SCPs
Explanation: The effective permissions of an IAM user are the result of the combination of all applicable policies, including user policies, group policies, resource-based policies, and any SCPs applied from AWS Organizations.
True or False: A benefit of central account management in AWS is the ability to enforce consistent access control policies across multiple accounts.
- A) True
- B) False
Answer: A) True
Explanation: Central account management through services like AWS Organizations allows consistent enforcement of access control policies across multiple accounts, enhancing security and compliance.
Great post on managing access controls across multiple AWS accounts. Helped a lot for my SAA-C03 exam prep!
Thanks for this extensive post, especially the IAM roles part.
Can someone explain the difference between IAM roles and SCPs?
The section on AWS Organizations was spot on. I wish I had known this before deploying in multiple regions!
What are the best practices for using AWS Organizations and IAM for access control?
Thank you for the insights!
In my experience, SCPs tend to complicate things if not planned properly. Any tips?
Appreciate the breakdown of IAM policies.