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An Introduction to AWS Config

An Introduction to AWS Config

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Stephen Jones
ยทMar 23, 2023ยท

7 min read

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Are you curious about one of the most powerful and my favorite services Amazon Web Services offers?

Look no further than AWS Config!

In this article, we'll dive into the ins and outs of this service that provides a detailed view of the configuration of your AWS resources.

AWS Config is a must-have for keeping track of your resources and monitoring changes over time. So let's get started and explore the world of AWS Config!

Infographic

Let's start with a one-minute overview in this one-pager:

Infographic for AWS Config

AWS Config Overview

AWS Config provides a comprehensive view of the configuration of your AWS resources. It keeps track of all the configuration attributes of supported resources within your AWS Account, including how resources are related to one another and how they were configured in the past.

Once AWS Config is enabled, you can easily monitor changes to your resources over time, identify potential security risks, react to those risks, and ensure compliance with industry standards and best practices.

AWS Config is an essential tool for managing your AWS resources and maintaining a secure and compliant environment. It's also used to feed other AWS Services such as Security Hub, Audit Manager, and Systems Manager.

AWS Config combination with other services

AWS Config Concepts

First, let's go through some of the foundational concepts of the service to help you understand how it all hangs together.

Resources

We create resources through the Console, Cli, or your favorite IAC tools such as Cloudformation or Terraform. These resources include IAM Users, EC2 Instances, EBS Volumes, S3 Buckets, and more.

As long as the resource is on the supported resources list for AWS Config, it will keep track of it for you.

Supported AWS Config Resources

Configuration Items

A configuration item is a snapshot of a supported resource at a specific point in time. It includes metadata, attributes, relationships, current configuration, and related events.

These configuration items are the building blocks that AWS Config uses to provide the configuration history of your AWS Resources.

For example, if AWS Config is recording Amazon S3 buckets, AWS Config creates a configuration item whenever a bucket is created, updated, or deleted

Configuration Item overview for AWS Config

Configuration Recorder

Think of Configuration Recorder as the engine that's responsible for storing all the configuration items for all supported resources within the region where AWS Config is running.

By default, the Configuration Recorder will store configuration items for all supported resources, but you can select a subset of resources if needed.

Configuration recorder to record config items

Configuration Snapshot

A configuration snapshot is a complete picture of the supported resources that exist in your account and their configurations. It's a collection of the configuration items that have been recorded, and it can be a useful tool for validating your configuration.

This snapshot provides a comprehensive view of your AWS resources, making it easier to ensure that everything is configured correctly.

These can be delivered to S3 or viewed in the AWS Config console.

Configuration snapshot

Configuration Stream

The configuration stream is the firehose of all the updates to those supported resources. Whenever a resource is created, modified, or deleted, AWS Config creates a configuration item and adds them to the configuration stream.

This stream is very powerful in that we can react to these events directly using Systems Manager or using other AWS services such as Lambda and many others.

The whole configuration snapshot in aws config

Relationships

Relationships provide information on how configuration items relate to one another, giving us a better picture of our resources.

For example:-

  • An IAM User configuration item could have a relationship with an IAM Group if it was a member of the Group.

  • An EC2 instance might include a relationship with an EBS Volume.

These relationships help to provide more context of how our resources are related.

relationship between configuration items

Remediation

Remediation allows us to fix stuff through automation if AWS Config detects a rule is NON_COMPLIANT. This is all driven through AWS Systems Manager Automation documents.

For example, we can deploy the 'restricted-ssh' rule to ensure none of our EC2 instances has open ssh access. If AWS Config detects a NON_COMPLIANCE for this rule it can trigger an SSM Automation Document to remove it.

This is all triggered in near real-time via the Configuration Stream described above.

AWS Config Rules

Rules give us a way to evaluate the configuration of our resources in near real-time.

They tap into the configuration stream as resources are created or updated and compare the configuration to a desired state defined in the rule. If the configuration of the resource deviates from the rule then it is marked as NON_COMPLIANT.

There are two types of rules Managed & Custom.

Managed Rules

Managed rules are provided by AWS. We can pick which ones are relevant to our environment and deploy them through the AWS Console, Cli or IAC tools. A full list is available here.

AWS Config offers managed rules to apply

Managed rules are also used by other AWS Services such as Security Hub to report overall compliance of resources within the AWS Account.

Custom Rules

We can also create our own rules either using the AWS Console, cfn-guard, or the AWS Config Rules Development Kit.

Custom rules are backed by Lambda and are a bit of an advanced topic that we won't be covering here.

Custom rules can also be used. These are backed by Lambda

Conformance Packs

Conformance packs are simply a collection of rules and remediations that you can deploy and monitor as a single collection in your AWS Account. They cover all sorts of security compliance frameworks such as PCI DSS but also operational best practices for things like monitoring, autoscaling, etc.

Setting Up AWS Config

To set up AWS Config within the console

  1. Sign in to the AWS Management Console and open the AWS Config console at https://console.aws.amazon.com/config/.

  2. If this is the first time you are opening the AWS Config console or you are setting up AWS Config in a new region, the AWS Config console page looks like the following:

    Setting up AWS Config

  3. Choose 1-click setup to launch AWS Config based on AWS best practices. You can also choose Get started to go through a more detailed setup process.

Once the AWS Config service is set up we can start deploying Rules & Conformance Packs.

Deploying Rules

Rules can be deployed through the AWS Console, Cli or IAC tools. Here are the steps to deploy through the AWS Console.

Choose Add rule

Rules overview in AWS Config

Next, select one of the AWS-managed rules. There are currently over 291 to choose from!

Specify rule types in AWS Config

Next, give it a meaningful name.

Give config rules names

Select the type of evaluation. We can run these rules based on configuration changes to our resources or periodically.

Evaluation mode of rules

Rules can also have parameters that control how the rule will function. Here we are setting the maximum access key age to 90 days.

Parameters for AWS Config Rules

Once our rule is deployed it can be reviewed in the Console and will show any compliant or non-compliant resources associated with it.

Review rule in the AWS Config

Deploying Conformance Packs

You can deploy them through the AWS Console by choosing Deploy conformance pack.

Deploy conformance pack to deploy your rule

Select one of the sample templates

Specify templates

Give it a name

Specify conformance pack details

Choose Deploy conformance pack

Deploy conformance pack

Once complete you will get a summary of the compliance score for all rules within the conformance pack.

Summary of the conformance

Pricing

As with all things AWS, they come at a cost. AWS Config has had a bad reputation for being expensive, but it is more reasonable since a previous pricing update.

There are a few aspects to the pricing model.

Configuration Items
You pay $0.003 per configuration item recorded in your AWS account per AWS Region.

That means whenever a supported resource is created, updated or deleted you'll be charged.

Config Rules

Rules are charged on the number of times they are evaluated. That means whenever a supported resource is created, updated or deleted the rule will be evaluated.

AWS Config rules evaluationsPrice
First 100,000 rule evaluations$0.001 per rule evaluation per region
Next 400,000 rule evaluations (100,001-500,000)$0.0008 per rule evaluation per region
500,001 and more rule evaluations$0.0005 per rule evaluation per region

Summary

In this post, we introduced you to the AWS Config concepts and walked through a few of the AWS Console screens to deploy Rules & Conformance Packs.

I hope you enjoyed the information here and are ready to go and learn more about the superpowers of AWS Config.

Thanks!

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