jaxley / aws-config-rules

[Node, Python, Java] Repository of sample Custom Rules for AWS Config.

AWS Config Rules Repository

AWS Community repository of custom Config rules. Contributions welcome. Instructions for leveraging these rules are below.

Please review each rule carefully and test within your dev/test environment before integrating into production.

Getting started with the developement of Rules

We recommend to use the RDK (Rule Development Kit) to author Config Rules. It is available here: https://github.com/awslabs/aws-config-rdk

Blog post: https://aws.amazon.com/blogs/mt/how-to-develop-custom-aws-config-rules-using-the-rule-development-kit/

Related Projects

RDK (Rule Development Kit) - https://github.com/awslabs/aws-config-rdk

Config Rules Engine (Deploy and manage Rules at scale) - https://github.com/awslabs/aws-config-engine-for-compliance-as-code

Adding a Rule to AWS Config

With the RDK

In the working folder,

rdk deploy NAME_OF_THE_RULE

Manually

You can use the sample functions in this repository to create Config rules that evaluate the configuration settings of your AWS resources. First, you use AWS Lambda to create a function that is based on the sample code. Then, you use AWS Config to create a rule that is associated with the function. When the rule’s trigger occurs, AWS Config invokes your function to evaluate your AWS resources.

Add a rule to AWS Config by completing the following steps. For more detailed steps, see Developing a Custom Rule for AWS Config in the AWS Config Developer Guide.

1. Navigate to the AWS Lambda Console.
   • Sign in to the AWS Management Console and open the AWS Lambda console.
   • Verify that your region is set to one that supports AWS Config rules.
   • For the list of supported regions, see AWS Config Regions and Endpoints.
2. Create a Lambda function.
   • Provide your code using the method required by the code entry type that you choose.
   • If you are adding a Python or Node.js function, you can copy and paste the code from the sample that you want to use. If you are adding a Java function, you must provide a JAR file that contains the Java classes. For instructions to build the JAR file, see Creating an AWS Config Rule with Java.
   • For the role that you assign to your function, choose the AWS Config Rules permission option. This includes AWSConfigRulesExecutionRole, an AWS managed policy that allows your Lambda function permission to "put" evaluations.
   • For Handler, if you are adding a Python or Node.js function, keep the default value. If you are adding a Java function, specify the handler value for to the Java function that you want to use. For the handler values, see AWS Config Rules (Java).
3. After you create the function, take note of its ARN.
4. Open the AWS Config console.
   • Verify that your region is set to the same region in which you created the AWS Lambda function for your custom rule.
5. Use the AWS Config console to add a custom rule.
   • For AWS Lambda function ARN, specify the ARN of the function that you created.
   • For Trigger type, if you are using any of the triggered samples from this repository, choose Configuration changes. If you are using any of the periodic samples from this repository, choose Periodic.
   • For the rule parameters, specify any required parameters.
   • For the trigger types and required parameters for each function, see AWS Config Rules (for Python and Node.js functions) or AWS Config Rules (Java).
   • Note: When you create a custom rule with the AWS Config console, the appropriate permissions for invoking the Lambda are automatically created for you. If you create a custom rule with the AWS CLI, you need to give AWS Config permission to invoke your Lambda function, using the aws lambda add-permission command.

After you create the rule, it displays on the Rules page, and AWS Config invokes its Lambda function. A summary of the evaluation results appears after several minutes.