What is AWS Config? Rules, Pricing, & CLI Config Explained

Introduction

AWS Config is a powerful managed service offered by Amazon Web Services that provides a detailed view of the configuration of AWS resources in your account. It tracks how these resources are related to each other and records their configuration changes over time, enabling continuous compliance auditing, security analysis, and operational troubleshooting. As organizations increasingly migrate workloads to the cloud, maintaining compliance with internal policies and external regulations becomes critical. AWS Config helps meet these needs by providing visibility and governance over resource configurations. 

What is AWS Config?

At its core, AWS Config is a service that continuously monitors and records your AWS resource configurations and allows you to automate the evaluation of recorded configurations against desired baselines or rules. It captures configuration details for supported AWS resources, including AWS EC2 instances, security groups, VPCs, and more. AWS Config also tracks relationships between resources-for example, which security groups are attached to which EC2 instances-and stores configuration history and snapshots for auditing purposes. 

AWS Config supports both AWS resources and software configurations inside EC2 instances and on-premises servers, giving a comprehensive view of your environment's state. This enables you to assess compliance with organizational policies, troubleshoot operational issues, and understand the impact of configuration changes. 

AWS Config Concepts

Several key concepts underpin AWS Config’s functionality: 

• Configuration Items: These are records that capture the state of a resource at a given time, including metadata, relationships, and configuration details. 

• Configuration Recorder: This component records configuration changes and snapshots of supported resources. 

• Configuration Rules: Rules evaluate whether your resource configurations comply with specified policies. AWS provides managed rules, or you can create custom rules using AWS Lambda. 

• Configuration History and Snapshots: AWS Config stores historical configuration data, enabling you to view resource states at any point in time. 

• Delivery Channels: These specify where AWS Config delivers configuration snapshots and notifications, typically to an S3 bucket and SNS topic. 

How AWS Config Works?

Once enabled, AWS Config discovers existing supported resources in your account and begins recording configuration items for each. It continuously monitors resource changes and generates new configuration items whenever a resource’s state changes. AWS Config stores these configuration items in an S3 bucket you specify and maintains a timeline of changes for auditing and troubleshooting. 

AWS Config also evaluates resource configurations against rules you define. These rules can be AWS managed or custom Lambda-backed functions. When a resource violates a rule, AWS Config marks it as non-compliant and can trigger notifications via SNS. This continuous evaluation helps enforce governance policies and detect drift from desired configurations. 

The process can be summarized as follows: 

• AWS Config discovers resources and records their configurations. 

• Configuration changes trigger new configuration items. 

• Config rules evaluate resource compliance. 

• Notifications and remediation actions can be triggered on non-compliance. 

• Configuration history is maintained for auditing and troubleshooting. 

Benefits of AWS Config

AWS Config offers several key benefits that improve cloud security, compliance, and operational efficiency: 

• Continuous Assessment: AWS Config continuously audits resource configurations against your policies, providing near real-time compliance status. You can deploy conformance packs-collections of rules and remediation actions-across your organization with a single click. 

• Continuous Monitoring: It records changes to resource configurations and software settings, enabling you to detect unauthorized or accidental modifications promptly. 

• Change Management: By tracking resource relationships and dependencies, AWS Config helps you understand the impact of changes before they are made, reducing risk and downtime. 

• Compliance Reporting: AWS Config provides visual dashboards and detailed reports that simplify compliance audits and governance. 

• Integration with AWS Services: It integrates with AWS Security Hub, CloudWatch, and Lambda to automate security workflows and remediation. 

• Operational Troubleshooting: Historical configuration data helps diagnose operational issues by showing what changed and when. 

Step-By-Step Process to Setup AWS Config

Setting up AWS Config is straightforward and involves the following steps: 

• Access AWS Config Console: Log into the AWS Management Console and navigate to AWS Config. 

• Select Resources to Record: Choose whether to record all supported resources or specify particular resource types. 

• Set Up Configuration Recorder: Create or select an IAM role that AWS Config uses to access resources. 

• Configure Delivery Channel: Specify an S3 bucket to store configuration snapshots and an SNS topic for notifications. 

• Enable AWS Config: Start the configuration recorder to begin tracking resource configurations. 

• Add Config Rules: Select from managed rules or create custom rules to evaluate resource compliance. 

• Monitor Compliance: Use the AWS Config dashboard to view compliance status and receive alerts on violations. 

You can also manage AWS Config programmatically using the AWS CLI, enabling automation of setup and compliance checks. 

AWS Config Pricing

AWS Config pricing is based primarily on three components: 

• Configuration Items Recorded: Charged per configuration item recorded. Continuous recording costs $0.003 per item, while periodic recording costs $0.012 per item. 

• Rule Evaluations: Charged per rule evaluation. The first 100,000 evaluations cost $0.001 each, with tiered discounts for higher volumes. 

• Conformance Pack Evaluations: Similar pricing to rule evaluations, charged per evaluation of rules within conformance packs. 

For example, recording 10,000 configuration items and 50,000 rule evaluations in a month might cost approximately $80-$100, depending on the mix of continuous and periodic recording and rule usage. To optimize costs, organizations should carefully select resource coverage and rules, and consider alternatives for large-scale metadata extraction. 

AWS Config vs CloudTrail

While both AWS Config and AWS CloudTrail provide visibility into AWS environments, they serve different purposes: 

• AWS Config focuses on recording and evaluating the configurations and relationships of AWS resources over time. It provides compliance auditing, configuration history, and resource change tracking. 

• AWS CloudTrail logs API calls and user activity across your AWS account, providing an audit trail of who did what and when. 

Together, they complement each other: CloudTrail tracks actions, while Config tracks the resulting resource states and compliance. 

Conclusion

AWS Config is an essential service for organizations aiming to maintain compliance, enhance security, and improve operational governance in their AWS environments. By continuously recording resource configurations, evaluating them against customizable rules, and providing detailed historical data, AWS Config empowers teams to detect misconfigurations, enforce policies, and respond quickly to changes. Understanding its pricing model and integrating it with other AWS services ensures you can leverage AWS Config efficiently and cost-effectively. Implementing AWS Config is a critical step toward a secure and compliant cloud infrastructure. Take up Netcom’s Learning AWS Training to boost your career in cloud computing!