Exploring Organizations

AWS Organizations provides a robust framework for managing multiple AWS accounts, while Control Tower automates the implementation of best practices and security controls. Together, they enable organizations to maintain secure, well-organized cloud environments while simplifying administrative overhead.

AWS Organizations Overview

AWS Organizations is a service that enables centralized management of multiple AWS accounts. It provides a hierarchical structure for managing cloud resources across different accounts under a single management point.

Core Components

• Management Account: The central account that provisions and manages the organization. Best practice is to keep this account free from workloads.

• Member Accounts: Individual accounts containing specific resources and workloads.

• Organizational Units (OUs): Groups of accounts that share access patterns or serve similar applications/services. Policies applied to an OU affect all accounts within it.

Benefits of Multiple AWS Accounts

Enhanced Security

1. Coarse-grained access control to cloud resources

2. Implementation of least privilege security principles

3. Restricted access to sensitive data through account isolation

4. Limited blast radius in case of security breaches

Operational Benefits

1. Workload grouping based on business purpose and ownership

2. Consolidated billing across all accounts

3. Bulk pricing discounts across the organization

4. Clear separation of concerns and responsibilities

AWS Control Tower

AWS Control Tower is an automated solution for managing multiple accounts, implementing best practices for organization management automatically.

Key Components

Landing Zone

• Initial setup environment for Control Tower

• Provides automatic application of guardrails to new accounts

• Establishes necessary permissions for account provisioning

Guardrails

• High-level rules governed by:

  • Service Control Policies

  • AWS Config rules

• Customizable at both OU and account levels

Baseline

• Combination of blueprints and guardrails

• Blueprints: CloudFormation stacks that:

  • Grant Control Tower access to managed accounts

  • Apply guardrails to member accounts

Control Tower Architecture

Core Structure

1. Management Account

   • Hosts Control Tower configuration

   • Integrates with IAM Identity Center (formerly AWS SSO)

2. Automatically Created Accounts

   • Log Archive Account: Aggregates CloudTrail logs

   • Audit Account: Contains cross-account audit roles for read access

3. Organizational Structure

   • Core OU: Contains system accounts

   • Custom OUs: Houses provisioned accounts

   • Automatic baseline application to new accounts

Best Practices

1. Keep management account free from workloads

2. Use organizational units to group similar accounts

3. Implement guardrails through Control Tower

4. Leverage automated account provisioning

5. Maintain centralized logging and auditing

6. Use IAM Identity Center for user access management