AWS Config terminology and concepts
To help you understand AWS Config, this topic explains some of the key concepts.
Contents
AWS Config Interfaces
AWS Config Console
You can manage the service using the AWS Config console. For more information about the AWS Management Console, see AWS Management Console.
AWS Config CLI
The AWS Command Line Interface is a unified tool that you can use to interact with AWS Config from the command line. For more information, see the AWS Command Line Interface User Guide. For a complete list of AWS Config CLI commands, see Available Commands.
AWS Config APIs
In addition to the console and the CLI, you can also use the AWS Config RESTful APIs to program AWS Config directly. For more information, see the AWS Config API Reference.
AWS Config SDKs
As an alternative to using the AWS Config API, you can use one of the AWS SDKs. Each SDK
consists of libraries and sample code for various programming languages and platforms. The
SDKs provide a convenient way to create programmatic access to AWS Config. For example, you can
use the SDKs to sign requests cryptographically, manage errors, and retry requests
automatically. For more information, see the Tools for
Amazon Web Services
Resource Management
Understanding the basic components of AWS Config will help you track resource inventory and changes and evaluate configurations of your AWS resources.
AWS Resources
AWS resources are entities that you create and manage using the AWS Management Console, the AWS Command Line Interface (CLI), the AWS SDKs, or AWS partner tools. Examples of AWS resources include Amazon EC2 instances, security groups, Amazon VPCs, and Amazon Elastic Block Store. AWS Config refers to each resource using its unique identifier, such as the resource ID or an Amazon Resource Name (ARN). For a list of resource types that AWS Config supports, see Supported Resource Types for AWS Config.
Resource Relationship
AWS Config discovers AWS resources in your account and then creates a map of relationships
between AWS resources. For example, a relationship might include an Amazon EBS volume
vol-123ab45d attached to an Amazon EC2 instance i-a1b2c3d4 that is
associated with security group sg-ef678hk.
For more information, see Supported Resource Types for AWS Config.
Configuration Recorder
The configuration recorder stores the configuration changes to the resource types in scope as configuration items. For more information, see Working with the configuration recorder.
There are two types of configuration recorders.
| Type | Description |
|---|---|
| Customer managed configuration recorder | A configuration recorder that you managed. The resource types in scope are set by you. By default, a customer managed configuration recorder records all supported resources in the AWS Region where AWS Config is running. |
| Service-linked configuration recorder | A configuration recorder that is linked to a specific AWS service. The resource types in scope are set by the linked service. |
Delivery Channel
As AWS Config continually records the changes that occur to your AWS resources, it sends notifications and updated configuration states through the delivery channel. You can manage the delivery channel to control where AWS Config sends configuration updates.
Configuration Items
A configuration item represents a point-in-time view of the various attributes of a supported AWS resource that exists in your account. The components of a configuration item include metadata, attributes, relationships, current configuration, and related events. AWS Config creates a configuration item whenever it detects a change to a resource type that it is recording. For example, if AWS Config is recording Amazon S3 buckets, AWS Config creates a configuration item whenever a bucket is created, updated, or deleted. You can also select for AWS Config to create a configuration item at the recording frequency that you set.
For more information, see Components of a Configuration Item and Recording Frequency.
Configuration History
A configuration history is a collection of the configuration items for a given resource over any time period. A configuration history can help you answer questions about, for example, when the resource was first created, how the resource has been configured over the last month, and what configuration changes were introduced yesterday at 9 AM. The configuration history is available to you in multiple formats. AWS Config automatically delivers a configuration history file for each resource type that is being recorded to an Amazon S3 bucket that you specify. You can select a given resource in the AWS Config console and navigate to all previous configuration items for that resource using the timeline. Additionally, you can access the historical configuration items for a resource from the API.
For more information, see Viewing Compliance History and Querying Compliance History.
Configuration Snapshot
A configuration snapshot is a collection of the configuration items for the supported resources that exist in your account. This configuration snapshot is a complete picture of the resources that are being recorded and their configurations. The configuration snapshot can be a useful tool for validating your configuration. For example, you may want to examine the configuration snapshot regularly for resources that are configured incorrectly or that potentially should not exist. The configuration snapshot is available in multiple formats. You can have the configuration snapshot delivered to an Amazon Simple Storage Service (Amazon S3) bucket that you specify. Additionally, you can select a point in time in the AWS Config console and navigate through the snapshot of configuration items using the relationships between the resources.
For more information, see Delivering Configuration Snapshots, Viewing Configuration Snapshots, and Example Configuration Snapshot.
Configuration Stream
A configuration stream is an automatically updated list of all configuration items for the resources that AWS Config is recording. Every time a resource is created, modified, or deleted, AWS Config creates a configuration item and adds to the configuration stream. The configuration stream works by using an Amazon Simple Notification Service (Amazon SNS) topic of your choice. The configuration stream is helpful for observing configuration changes as they occur so that you can spot potential problems, generating notifications if certain resources are changed, or updating external systems that need to reflect the configuration of your AWS resources.
AWS Config Rules
An AWS Config rule is a compliance check that helps you manage your ideal configuration settings for specific AWS resources. AWS Config evaluates whether your resource configurations comply with relevant rules and displays the compliance results.
Evaluation Results
There are four possible evaluation results for an AWS Config rule.
| Evaluation result | Description |
|---|---|
COMPLIANT |
The rule passes the conditions of the compliance check. |
NON_COMPLIANT |
The rule fails the conditions of the compliance check. |
ERROR |
The one of the required/optional parameters is not valid, not of the correct type, or is formatted incorrectly. |
NOT_APPLICABLE |
Used to filter out resources that the logic of the rule cannot be applied to. For example, the alb-desync-mode-check rule only checks Application Load Balancers, and ignores Network Load Balancers and Gateway Load Balancers. |
Rule Types
There are two types of rules. For more information about the structure of rule definitions and rule metadata, see Components of an AWS Config Rule.
| Type | Description | More information |
|---|---|---|
| Managed rules | Predefined, customizable rules created by AWS Config. | For a list of managed rules, see List of AWS Config Managed Rules. |
| Custom rules | Rules that you create from scratch. There are two ways to create
AWS Config custom rules: Lambda functions (AWS Lambda Developer Guide) and Guard (Guard GitHub
Repository |
For more information, see Creating AWS Config Custom Policy Rules and Creating AWS Config Custom Lambda Rules. |
Trigger Types
After you add a rule to your account, AWS Config compares your resources to the conditions of the rule. After this initial evaluation, AWS Config continues to run evaluations each time one is triggered. The evaluation triggers are defined as part of the rule, and they can include the following types.
| Trigger type | Description |
|---|---|
| Configuration changes | AWS Config runs evaluations for the rule when there is a resource that matches
the rule's scope and there is a change in configuration of the resource. The
evaluation runs after AWS Config sends a configuration item change
notification.
You choose which resources initiate the evaluation by defining the rule's scope. The scope can include the following:
AWS Config runs the evaluation when it detects a change to a resource that matches the rule's scope. You can use the scope to define which resources initiate evaluations. |
| Periodic | AWS Config runs evaluations for the rule at a frequency that you choose; for example, every 24 hours. |
| Hybrid | Some rules have both configuration change and periodic triggers. For these rules, AWS Config evaluates your resources when it detects a configuration change and also at the frequency that you specify. |