AWS Config rules are a powerful feature within AWS that enables continuous evaluation and monitoring of your AWS resource configurations against desired compliance standards. As a SysOps Administrator, understanding Config rules is essential for maintaining governance and ensuring resources adhere …AWS Config rules are a powerful feature within AWS that enables continuous evaluation and monitoring of your AWS resource configurations against desired compliance standards. As a SysOps Administrator, understanding Config rules is essential for maintaining governance and ensuring resources adhere to organizational policies.
AWS Config rules work by evaluating the configuration settings of your AWS resources and determining whether they comply with specified conditions. There are two types of rules: AWS Managed Rules and Custom Rules. Managed Rules are pre-built by AWS and cover common compliance scenarios like checking if S3 buckets have encryption enabled or if EC2 instances use approved AMIs. Custom Rules allow you to create your own evaluation logic using AWS Lambda functions for specific organizational requirements.
Rules can be triggered in two ways: configuration changes or periodic evaluation. Change-triggered rules run whenever a relevant resource configuration changes, while periodic rules run at specified intervals (hourly, daily, etc.).
When a rule evaluates a resource, it marks it as either COMPLIANT or NON_COMPLIANT. You can view compliance status through the AWS Config dashboard, set up SNS notifications for non-compliant resources, and integrate with AWS Systems Manager for automated remediation actions.
For deployment and automation, Config rules integrate seamlessly with CloudFormation through conformance packs, which are collections of rules and remediation actions packaged together. This enables infrastructure-as-code approaches to compliance management.
Key use cases include security baseline enforcement, operational best practices validation, and audit preparation. Config rules also support multi-account deployments through AWS Organizations, allowing centralized compliance management across your entire AWS environment.
Remember that AWS Config must be enabled in each region where you want to monitor resources, and there are costs associated with both the configuration recordings and rule evaluations. Proper planning of rule scope and evaluation frequency helps optimize costs while maintaining effective compliance monitoring.
AWS Config Rules are essential for maintaining compliance, security, and governance across your AWS infrastructure. They enable you to automatically evaluate whether your AWS resources comply with your organization's policies and best practices. For SysOps Administrators, understanding Config Rules is crucial for implementing automated compliance checking, detecting configuration drift, and maintaining operational excellence.
What Are AWS Config Rules?
AWS Config Rules are customizable rules that AWS Config uses to evaluate whether your AWS resources comply with desired configurations. There are two types of rules:
AWS Managed Rules: Pre-built rules created and maintained by AWS. Examples include checking if S3 buckets have encryption enabled, if EC2 instances are using approved AMIs, or if security groups allow unrestricted SSH access.
Custom Rules: Rules you create using AWS Lambda functions to define your own compliance logic. These allow you to implement organization-specific requirements that managed rules don't cover.
How AWS Config Rules Work
1. Configuration Recording: AWS Config continuously monitors and records your AWS resource configurations.
2. Rule Evaluation: When a resource is created, modified, or deleted (change-triggered) or at specified intervals (periodic), Config Rules evaluate the resource against defined criteria.
3. Compliance Status: Each resource is marked as COMPLIANT, NON_COMPLIANT, or NOT_APPLICABLE.
4. Remediation: You can configure automatic remediation actions using AWS Systems Manager Automation documents to fix non-compliant resources.
Trigger Types: - Configuration Changes: Rule runs when specific resource types are created, changed, or deleted - Periodic: Rule runs at specified frequency (1 hour, 3 hours, 6 hours, 12 hours, or 24 hours)
Key Components: - Config Recorder: Records configuration changes - Delivery Channel: Sends configuration snapshots and history to S3 - Aggregator: Collects Config data from multiple accounts and regions
Common AWS Managed Rules to Know: - s3-bucket-public-read-prohibited: Checks if S3 buckets allow public read access - encrypted-volumes: Checks if EBS volumes are encrypted - restricted-ssh: Checks for unrestricted SSH access in security groups - required-tags: Ensures resources have required tags - cloudtrail-enabled: Verifies CloudTrail is enabled
Exam Tips: Answering Questions on AWS Config Rules
1. Understand the Difference Between Config and CloudTrail: AWS Config tracks WHAT your resources look like (configuration state), while CloudTrail tracks WHO did WHAT (API calls). If a question asks about resource configuration compliance, think Config. If it asks about auditing user actions, think CloudTrail.
2. Know When to Use Config vs Other Services: For compliance checking and configuration tracking, choose Config. For real-time threat detection, consider GuardDuty. For security findings aggregation, think Security Hub.
3. Remediation Questions: When asked about automatically fixing non-compliant resources, remember that Config Rules integrate with Systems Manager Automation for remediation actions.
4. Multi-Account Scenarios: Questions about aggregating compliance data across multiple accounts or regions should point you toward Config Aggregators.
5. Cost Considerations: Remember that you pay per Config Rule evaluation and per configuration item recorded. This may appear in cost optimization questions.
6. Custom Rules: If a question describes a compliance requirement that doesn't match any standard AWS rule, the answer likely involves creating a custom rule with Lambda.
7. Conformance Packs: For questions about deploying multiple related rules as a package, think Conformance Packs. These are useful for compliance frameworks like PCI-DSS or HIPAA.
8. Timeline and History: Config maintains a configuration timeline, so questions about viewing historical configurations or determining when a change occurred point to AWS Config.
9. Resource Relationships: Config tracks resource relationships, so questions about understanding dependencies between resources should lead you to Config.
10. Evaluation Modes: Proactive evaluation can assess resources before deployment (useful for CI/CD pipelines), while detective evaluation assesses existing resources.