Evaluating Your Resources with AWS Config Rules - AWS Config

Evaluating Your Resources with AWS Config Rules

When you create custom rules or use managed rules, AWS Config evaluates your resources against those rules. You can run on-demand evaluations for resources against your rules. For example, this is helpful when you create a custom rule and want to check that AWS Config is correctly evaluating your resources or to identify if there is an issue with the evaluation logic of your AWS Lambda function.

Example

  1. You create a custom rule that evaluates whether your IAM users have active access keys.

  2. AWS Config evaluates your resources against your custom rule.

  3. An IAM user who doesn't have an active access key exists in your account. Your rule doesn't correctly flag this resource as NON_COMPLIANT.

  4. You fix the rule and start the evaluation again.

  5. Because you fixed your rule, the rule correctly evaluates your resources, and flags the IAM user resource as NON_COMPLIANT.

When you add a rule to your account, you can specify when in the resource creation and management process that you want AWS Config to evaluate your resources. The resource creation and management process is known as resource provisioning. You choose the evaluation mode to specify when in this process you want AWS Config to evaluate your resources.

Depending on the rule, AWS Config can evaluate your resource configurations before a resource has been deployed, after a resource has been deployed, or both. Evaluating a resource before it has been deployed is proactive evaluation. Evaluating a resource after it has been deployed is detective evaluation.

Use proactive evaluation to evaluate resources before they have been deployed. This allows you to evaluate whether a set of resource properties, if used to define an AWS resource, would be COMPLIANT or NON_COMPLIANT given the set of proactive rules that you have in your account in your Region.

The Resource type schema states the properties of a resource. You can find the resource type schema in "AWS public extensions" within the AWS CloudFormation registry or with the following CLI commmand:

aws cloudformation describe-type --type-name "AWS::S3::Bucket" --type RESOURCE

For more information, see Managing extensions through the AWS CloudFormation registry and AWS resource and property types reference in the AWS CloudFormation User Guide.

Note

Proactive rules do not remediate resources that are flagged as NON_COMPLIANT or prevent them from being deployed.

Evaluating your Resources

To turn on proactive evalution

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

  2. In the AWS Management Console menu, verify that the Region selector is set to a Region that supports AWS Config rules. For the list of supported AWS Regions, see AWS Config Regions and Endpoints in the Amazon Web Services General Reference.

  3. In the left navigation, choose Rules. For a list of managed rules that support proactive evaluation, see List of AWS Config Managed Rules by Evaluation Mode.

  4. Choose a rule, and then choose Edit rule for the rule that you want to update.

  5. For Evaluation mode, choose Turn on proactive evaluation to allow you to run evaluations on the configuration settings of your resources before they are deployed.

  6. Choose Save.

Note

You can also turn on proactive evaluation using the put-config-rule command and enabling PROACTIVE for EvaluationModes or using the PutConfigRule action and enabling PROACTIVE for EvaluationModes.

After you have turned on proactive evaluation, you can use the StartResourceEvaluation API and GetResourceEvaluationSummary API to check if the resources you specify in these commands would be flagged as NON_COMPLIANT by the proactive rules in your account in your Region.

For example, start with the StartResourceEvaluation API:

aws configservice start-resource-evaluation --evaluation-mode PROACTIVE
                --resource-details '{"ResourceId":"MY_RESOURCE_ID",
                                     "ResourceType":"AWS::RESOURCE::TYPE",
                                     "ResourceConfiguration":"RESOURCE_DEFINITION_AS_PER_THE_RESOURCE_CONFIGURATION_SCHEMA",
                                     "ResourceConfigurationSchemaType":"CFN_RESOURCE_SCHEMA"}'

You should receive the ResourceEvaluationId in the output:

{
    "ResourceEvaluationId": "MY_RESOURCE_EVALUATION_ID"
}

Then, use the ResourceEvaluationId with the GetResourceEvaluationSummary API to check the evaluation result:

aws configservice get-resource-evaluation-summary
    --resource-evaluation-id MY_RESOURCE_EVALUATION_ID

You should receive output similiar to the following:

{
    "ResourceEvaluationId": "MY_RESOURCE_EVALUATION_ID",
    "EvaluationMode": "PROACTIVE",
    "EvaluationStatus": {
        "Status": "SUCCEEDED"
    },
    "EvaluationStartTimestamp": "2022-11-15T19:13:46.029000+00:00",
    "Compliance": "COMPLIANT",
    "ResourceDetails": {
        "ResourceId": "MY_RESOURCE_ID",
        "ResourceType": "AWS::RESOURCE::TYPE",
        "ResourceConfiguration": "RESOURCE_DEFINITION_AS_PER_THE_RESOURCE_CONFIGURATION_SCHEMA"
    }
}

To see additional information about the evaluation result, such as which rule flagged a resource as NON_COMPLIANT, use the GetComplianceDetailsByResource API.

Use detective evaluation to evaluate resources that have already been deployed. This allows you to evaluate the configuration settings of your existing resources.

Evaluating your Resources (Console)

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

  2. In the AWS Management Console menu, check that the region selector is set to a Region that supports AWS Config rules. For the list of supported regions, see AWS Config Regions and Endpoints in the Amazon Web Services General Reference.

  3. In the navigation pane, choose Rules. The Rules page shows the name, associated remediation action, and compliance status of each rule.

  4. Choose a rule from the table.

  5. From the Actions dropdown list, choose Re-evaluate.

  6. AWS Config starts evaluating the resources against your rule.

Note

You can re-evaluate a rule one time each minute. You must wait for AWS Config to complete the evaluation for your rule before you start another evaluation. You can't run an evaluation if at the same time the rule is being updated or if the rule is being deleted.

Evaluating your Resources (CLI)

  • Use the start-config-rules-evaluation command:

    $ aws configservice start-config-rules-evaluation --config-rule-names ConfigRuleName

    AWS Config starts evaluating the recorded resource configurations against your rule. You can also specify multiple rules in your request:

    $ aws configservice start-config-rules-evaluation --config-rule-names ConfigRuleName1 ConfigRuleName2 ConfigRuleName3

Evaluating your Resources (API)

Use the StartConfigRulesEvaluation action.