Crafting a Robust AWS Environment: Mastering Organizations, Landing Zone, SCPs, and Control Tower Part-1

As companies expand their use of AWS, managing a multi-account environment becomes increasingly complex. With more accounts come challenges in security, governance, and scalability. AWS provides tools like AWS Organizations, Landing Zone, Service Control Policies (SCPs), and Control Tower to help streamline and secure your cloud infrastructure. In this article, we’ll explore how each of these services contributes to a well-architected AWS environment.

Why Use a Multi-Account AWS Strategy?

Using multiple AWS accounts allows for clearer separation of workloads, improved security, and better control over costs. For example, separating development and production environments into different accounts can prevent inadvertent access to production resources. However, as the number of accounts grows, managing them becomes challenging, particularly around security and compliance.

AWS offers a suite of services designed to help companies manage, secure, and optimize their multi-account environments. Here’s an overview of AWS Organizations, Landing Zone, SCPs, and Control Tower and how they work together.

1. AWS Organizations: Structuring Your AWS Accounts

AWS Organizations is a service that lets you manage multiple AWS accounts from a single, centralized location. With Organizations, you can group accounts into Organizational Units (OUs) based on business needs, such as production, development, or testing. This allows for simplified, hierarchical management of permissions and policies across accounts.

Key Features:

• Centralized Account Management: Easily manage access and permissions across accounts.

• Organizational Units (OUs): Structure accounts in a way that aligns with your business needs.

• Consolidated Billing: Track and optimize costs across accounts.

Using AWS Organizations as a foundation, you can apply policies consistently across accounts, which reduces administrative overhead and enhances security.

2. AWS Landing Zone: Building a Secure AWS Foundation

Before AWS Control Tower, AWS Landing Zone was the primary solution for automating the setup of a secure, multi-account environment. AWS Landing Zone provides a standardized, scalable, and secure baseline for your AWS accounts. While it requires more setup than Control Tower, it allows for greater customization and flexibility.

Key Components of AWS Landing Zone:

• AWS Account Vending Machine (AVM): Automates account creation and enforces security best practices.

• Pre-configured Accounts: Includes foundational accounts such as Security, Log Archive, and Shared Services.

• Networking and Security Baselines: Ensures that newly created accounts follow a common security and network setup.

While AWS Control Tower has mostly replaced Landing Zone, some organizations still use it for custom environments that require a high degree of flexibility.

3. Service Control Policies (SCPs): Enforcing Guardrails Across Accounts

Service Control Policies (SCPs) are policies that define what actions users and roles can perform within the accounts in an AWS Organization. SCPs enable you to implement permission guardrails across accounts, ensuring that users only have access to the services and actions that comply with your organization’s security and governance requirements.

How SCPs Work:

• SCPs apply to all identities (users and roles) within an AWS account, including root users.

• They set guardrails, ensuring that certain actions are restricted or allowed based on your policies.

• SCPs do not grant permissions but act as an overarching control on top of AWS IAM policies.

For example, you can create an SCP that blocks the use of specific high-risk services (like terminating production databases) across all accounts. This helps prevent accidental or malicious actions.

SCP Best Practices:

• Least Privilege: Start with minimal permissions and only expand as needed.

• Inheritance: Policies applied at the root level cascade down, so plan carefully to avoid unintentional access blocks.

• Testing: Always test SCPs on a single account or OU to verify they work as expected before applying them broadly.

4. AWS Control Tower: Simplifying Multi-Account Setup and Governance

AWS Control Tower builds on AWS Organizations and automates the setup of a secure, well-governed, multi-account AWS environment. Control Tower simplifies and accelerates multi-account setups by providing a pre-defined landing zone and a set of built-in guardrails.

Key Features of AWS Control Tower:

• Automated Account Setup: Use Account Factory to create new accounts with the right permissions, logging, and networking pre-configured.

• Guardrails: Control Tower provides mandatory and optional guardrails for best-practice compliance, such as ensuring accounts have logging enabled.

• Dashboards: Control Tower offers an integrated dashboard to monitor compliance and track resources across accounts.

Control Tower is ideal for organizations seeking a fast, easy setup for multi-account AWS environments with built-in security and compliance controls. It is especially useful for organizations that want to get started quickly without the need for heavy customization.

Control Tower vs. Landing Zone:

Control Tower is typically recommended for organizations that prefer a turnkey solution with less customization but high security. If your organization needs more flexibility or has custom compliance requirements, AWS Landing Zone might be a better fit.

How AWS Organizations, Landing Zone, SCPs, and Control Tower Work Together

These AWS services complement each other to help create a secure, scalable, and compliant AWS environment:

1. AWS Organizations provides the structure for managing multiple AWS accounts.

2. Landing Zone (or Control Tower) provides a baseline environment with foundational security and network configurations.

3. SCPs enforce policies across accounts to ensure consistent security and compliance.

4. AWS Control Tower simplifies account provisioning, compliance tracking, and governance with its guardrails.

Using these services together enables a robust, scalable setup with clear account boundaries, policy enforcement, and automation for account creation and compliance. AWS Control Tower and SCPs, in particular, add an additional layer of security and governance, making it easier to monitor and control resources across all accounts.

Conclusion

In a multi-account AWS environment, setting up and managing accounts with security, compliance, and scalability in mind is crucial. AWS Organizations, Landing Zone, SCPs, and Control Tower provide the building blocks needed to manage a complex AWS setup effectively. By structuring accounts, setting guardrails, and using automated account provisioning, you create an environment that is secure, efficient, and aligned with best practices.

Whether you’re just starting or scaling a multi-account AWS architecture, leveraging these AWS tools will help you maintain control and agility as your organization grows in the cloud.