Guardrails unveiled

Control Tower’s guardrails provide a powerful mechanism for automating compliance and best practice enforcement across your AWS environment. Think of them as customizable barriers and monitors ensuring your cloud operations stay within your defined boundaries. Let’s break down their types:

Preventive guardrails: These are designed to proactively enforce compliance by disallowing actions that violate policies. For example, a preventive guardrail might restrict the creation of S3 buckets that are publicly accessible. This ensures that sensitive data is not accidentally exposed.
Detective guardrails: These monitor for non-compliance and generate alerts when violations occur. They don’t block actions but serve as a monitoring mechanism. For example, if an EC2 instance is launched without the required tags, a detective guardrail would flag this for review.
Custom guardrails: Control Tower allows for the creation of custom guardrails using Config. This enables organizations to define their own set of compliance rules tailored to their specific needs. Custom guardrails can be as simple as checking for specific tags on resources or as complex as ensuring encryption across multiple services.

Control Tower in the real world

Let’s explore how Control Tower functions in a complex, real-world setting.

Scenario

Imagine a multinational retail corporation that has recently transitioned its entire inventory management system to AWS. The company operates in multiple countries and has different compliance requirements for data storage and processing in each region. The challenge is to maintain a consistent governance framework across all these regions while adhering to local compliance laws.

Solution

The company decides to implement Control Tower for centralized governance. They set up a landing zone with different OUs for each region. Within these OUs, they apply various guardrails:

To comply with data residency laws, they set up a preventive guardrail that restricts data storage to S3 buckets located only in the respective regions.
They also set up detective guardrails to monitor real-time usage of services such as EC2 and RDS. If any resource is spun up without proper tagging, indicating its business unit and compliance category, alerts are sent to the central security team.
To ensure that only encrypted data is stored in RDS instances, they create a custom guardrail that flags any RDS instances without encryption.

Outcome

Within the first month of implementation, the preventive guardrail blocks several attempts to create S3 buckets in unauthorized regions, thereby avoiding potential legal complications. The detective guardrails flag a handful of resources that were incorrectly tagged or not tagged at all, allowing the security team to rectify the issues before they escalate. The custom guardrail ensures that all RDS instances are encrypted, adding an extra layer of security.

By using Control Tower’s guardrails, the company successfully establishes a robust, automated governance framework that adapts to its complex, multi-regional operational structure. This not only saves time but also significantly reduces the risk of human error, ensuring a more secure and compliant environment.