class CfnRule (construct)

Language	Type name
.NET	`Amazon.CDK.AWS.Events.CfnRule`
Go	`github.com/aws/aws-cdk-go/awscdk/v2/awsevents#CfnRule`
Java	`software.amazon.awscdk.services.events.CfnRule`
Python	`aws_cdk.aws_events.CfnRule`
TypeScript	`aws-cdk-lib` » `aws_events` » `CfnRule`

Implements IConstruct, IDependable, IInspectable

Creates or updates the specified rule.

Rules are enabled by default, or based on value of the state. You can disable a rule using DisableRule .

A single rule watches for events from a single event bus. Events generated by AWS services go to your account's default event bus. Events generated by SaaS partner services or applications go to the matching partner event bus. If you have custom applications or services, you can specify whether their events go to your default event bus or a custom event bus that you have created. For more information, see CreateEventBus .

If you are updating an existing rule, the rule is replaced with what you specify in this PutRule command. If you omit arguments in PutRule , the old values for those arguments are not kept. Instead, they are replaced with null values.

When you create or update a rule, incoming events might not immediately start matching to new or updated rules. Allow a short period of time for changes to take effect.

A rule must contain at least an EventPattern or ScheduleExpression. Rules with EventPatterns are triggered when a matching event is observed. Rules with ScheduleExpressions self-trigger based on the given schedule. A rule can have both an EventPattern and a ScheduleExpression, in which case the rule triggers on matching events as well as on a schedule.

Most services in AWS treat : or / as the same character in Amazon Resource Names (ARNs). However, EventBridge uses an exact match in event patterns and rules. Be sure to use the correct ARN characters when creating event patterns so that they match the ARN syntax in the event you want to match.

In EventBridge, it is possible to create rules that lead to infinite loops, where a rule is fired repeatedly. For example, a rule might detect that ACLs have changed on an S3 bucket, and trigger software to change them to the desired state. If the rule is not written carefully, the subsequent change to the ACLs fires the rule again, creating an infinite loop.

To prevent this, write the rules so that the triggered actions do not re-fire the same rule. For example, your rule could fire only if ACLs are found to be in a bad state, instead of after any change.

An infinite loop can quickly cause higher than expected charges. We recommend that you use budgeting, which alerts you when charges exceed your specified limit. For more information, see Managing Your Costs with Budgets .

As an aid to help you jumpstart developing CloudFormation templates, the EventBridge console enables you to create templates from the existing rules in your account. For more information, see Generating CloudFormation templates from an EventBridge rule in the Amazon EventBridge User Guide .

Example

// The code below shows an example of how to instantiate this type.
// The values are placeholders you should change.
import { aws_events as events } from 'aws-cdk-lib';

declare const eventPattern: any;
const cfnRule = new events.CfnRule(this, 'MyCfnRule', /* all optional props */ {
  description: 'description',
  eventBusName: 'eventBusName',
  eventPattern: eventPattern,
  name: 'name',
  roleArn: 'roleArn',
  scheduleExpression: 'scheduleExpression',
  state: 'state',
  targets: [{
    arn: 'arn',
    id: 'id',

    // the properties below are optional
    appSyncParameters: {
      graphQlOperation: 'graphQlOperation',
    },
    batchParameters: {
      jobDefinition: 'jobDefinition',
      jobName: 'jobName',

      // the properties below are optional
      arrayProperties: {
        size: 123,
      },
      retryStrategy: {
        attempts: 123,
      },
    },
    deadLetterConfig: {
      arn: 'arn',
    },
    ecsParameters: {
      taskDefinitionArn: 'taskDefinitionArn',

      // the properties below are optional
      capacityProviderStrategy: [{
        capacityProvider: 'capacityProvider',

        // the properties below are optional
        base: 123,
        weight: 123,
      }],
      enableEcsManagedTags: false,
      enableExecuteCommand: false,
      group: 'group',
      launchType: 'launchType',
      networkConfiguration: {
        awsVpcConfiguration: {
          subnets: ['subnets'],

          // the properties below are optional
          assignPublicIp: 'assignPublicIp',
          securityGroups: ['securityGroups'],
        },
      },
      placementConstraints: [{
        expression: 'expression',
        type: 'type',
      }],
      placementStrategies: [{
        field: 'field',
        type: 'type',
      }],
      platformVersion: 'platformVersion',
      propagateTags: 'propagateTags',
      referenceId: 'referenceId',
      tagList: [{
        key: 'key',
        value: 'value',
      }],
      taskCount: 123,
    },
    httpParameters: {
      headerParameters: {
        headerParametersKey: 'headerParameters',
      },
      pathParameterValues: ['pathParameterValues'],
      queryStringParameters: {
        queryStringParametersKey: 'queryStringParameters',
      },
    },
    input: 'input',
    inputPath: 'inputPath',
    inputTransformer: {
      inputTemplate: 'inputTemplate',

      // the properties below are optional
      inputPathsMap: {
        inputPathsMapKey: 'inputPathsMap',
      },
    },
    kinesisParameters: {
      partitionKeyPath: 'partitionKeyPath',
    },
    redshiftDataParameters: {
      database: 'database',

      // the properties below are optional
      dbUser: 'dbUser',
      secretManagerArn: 'secretManagerArn',
      sql: 'sql',
      sqls: ['sqls'],
      statementName: 'statementName',
      withEvent: false,
    },
    retryPolicy: {
      maximumEventAgeInSeconds: 123,
      maximumRetryAttempts: 123,
    },
    roleArn: 'roleArn',
    runCommandParameters: {
      runCommandTargets: [{
        key: 'key',
        values: ['values'],
      }],
    },
    sageMakerPipelineParameters: {
      pipelineParameterList: [{
        name: 'name',
        value: 'value',
      }],
    },
    sqsParameters: {
      messageGroupId: 'messageGroupId',
    },
  }],
});

Initializer

new CfnRule(scope: Construct, id: string, props?: CfnRuleProps)

Parameters

scope Construct — Scope in which this resource is defined.
id string — Construct identifier for this resource (unique in its scope).
props CfnRuleProps — Resource properties.

Construct Props

Name	Type	Description
description?	`string`	The description of the rule.
eventBusName?	`string`	The name or ARN of the event bus associated with the rule.
eventPattern?	`any`	The event pattern of the rule.
name?	`string`	The name of the rule.
roleArn?	`string`	The Amazon Resource Name (ARN) of the role that is used for target invocation.
scheduleExpression?	`string`	The scheduling expression.
state?	`string`	The state of the rule.
targets?	`IResolvable` `\|` `IResolvable` `\|` `TargetProperty[]`	Adds the specified targets to the specified rule, or updates the targets if they are already associated with the rule.

description?

Type: string (optional)

The description of the rule.

eventBusName?

Type: string (optional)

The name or ARN of the event bus associated with the rule.

If you omit this, the default event bus is used.

eventPattern?

Type: any (optional)

The event pattern of the rule.

For more information, see Events and Event Patterns in the Amazon EventBridge User Guide .

name?

Type: string (optional)

The name of the rule.

roleArn?

Type: string (optional)

The Amazon Resource Name (ARN) of the role that is used for target invocation.

If you're setting an event bus in another account as the target and that account granted permission to your account through an organization instead of directly by the account ID, you must specify a RoleArn with proper permissions in the Target structure, instead of here in this parameter.

scheduleExpression?

Type: string (optional)

The scheduling expression.

For example, "cron(0 20 * * ? *)", "rate(5 minutes)". For more information, see Creating an Amazon EventBridge rule that runs on a schedule .

state?

Type: string (optional)

The state of the rule.

Valid values include:

DISABLED : The rule is disabled. EventBridge does not match any events against the rule.
ENABLED : The rule is enabled. EventBridge matches events against the rule, except for AWS management events delivered through CloudTrail.
ENABLED_WITH_ALL_CLOUDTRAIL_MANAGEMENT_EVENTS : The rule is enabled for all events, including AWS management events delivered through CloudTrail.

Management events provide visibility into management operations that are performed on resources in your AWS account. These are also known as control plane operations. For more information, see Logging management events in the CloudTrail User Guide , and Filtering management events from AWS services in the Amazon EventBridge User Guide .

This value is only valid for rules on the default event bus or custom event buses . It does not apply to partner event buses .

targets?

Type: IResolvable | IResolvable | TargetProperty[] (optional)

Adds the specified targets to the specified rule, or updates the targets if they are already associated with the rule.

Targets are the resources that are invoked when a rule is triggered.

The maximum number of entries per request is 10.

Each rule can have up to five (5) targets associated with it at one time.

For a list of services you can configure as targets for events, see EventBridge targets in the Amazon EventBridge User Guide .

Creating rules with built-in targets is supported only in the AWS Management Console . The built-in targets are:

Amazon EBS CreateSnapshot API call
Amazon EC2 RebootInstances API call
Amazon EC2 StopInstances API call
Amazon EC2 TerminateInstances API call

For some target types, PutTargets provides target-specific parameters. If the target is a Kinesis data stream, you can optionally specify which shard the event goes to by using the KinesisParameters argument. To invoke a command on multiple EC2 instances with one rule, you can use the RunCommandParameters field.

To be able to make API calls against the resources that you own, Amazon EventBridge needs the appropriate permissions:

For AWS Lambda and Amazon SNS resources, EventBridge relies on resource-based policies.
For EC2 instances, Kinesis Data Streams, AWS Step Functions state machines and API Gateway APIs, EventBridge relies on IAM roles that you specify in the RoleARN argument in PutTargets .

For more information, see Authentication and Access Control in the Amazon EventBridge User Guide .

If another AWS account is in the same region and has granted you permission (using PutPermission ), you can send events to that account. Set that account's event bus as a target of the rules in your account. To send the matched events to the other account, specify that account's event bus as the Arn value when you run PutTargets . If your account sends events to another account, your account is charged for each sent event. Each event sent to another account is charged as a custom event. The account receiving the event is not charged. For more information, see Amazon EventBridge Pricing .

Input , InputPath , and InputTransformer are not available with PutTarget if the target is an event bus of a different AWS account.

If you are setting the event bus of another account as the target, and that account granted permission to your account through an organization instead of directly by the account ID, then you must specify a RoleArn with proper permissions in the Target structure. For more information, see Sending and Receiving Events Between AWS Accounts in the Amazon EventBridge User Guide .

If you have an IAM role on a cross-account event bus target, a PutTargets call without a role on the same target (same Id and Arn ) will not remove the role.

For more information about enabling cross-account events, see PutPermission .

Input , InputPath , and InputTransformer are mutually exclusive and optional parameters of a target. When a rule is triggered due to a matched event:

If none of the following arguments are specified for a target, then the entire event is passed to the target in JSON format (unless the target is Amazon EC2 Run Command or Amazon ECS task, in which case nothing from the event is passed to the target).
If Input is specified in the form of valid JSON, then the matched event is overridden with this constant.
If InputPath is specified in the form of JSONPath (for example, $.detail ), then only the part of the event specified in the path is passed to the target (for example, only the detail part of the event is passed).
If InputTransformer is specified, then one or more specified JSONPaths are extracted from the event and used as values in a template that you specify as the input to the target.

When you specify InputPath or InputTransformer , you must use JSON dot notation, not bracket notation.

When you add targets to a rule and the associated rule triggers soon after, new or updated targets might not be immediately invoked. Allow a short period of time for changes to take effect.

This action can partially fail if too many requests are made at the same time. If that happens, FailedEntryCount is non-zero in the response and each entry in FailedEntries provides the ID of the failed target and the error code.

Properties

Name	Type	Description
attrArn	`string`	The ARN of the rule, such as `arn:aws:events:us-east-2:123456789012:rule/example` .
cfnOptions	`ICfnResourceOptions`	Options for this resource, such as condition, update policy etc.
cfnProperties	`{ [string]: any }`
cfnResourceType	`string`	AWS resource type.
creationStack	`string[]`
logicalId	`string`	The logical ID for this CloudFormation stack element.
node	`Node`	The tree node.
ref	`string`	Return a string that will be resolved to a CloudFormation `{ Ref }` for this element.
stack	`Stack`	The stack in which this element is defined.
description?	`string`	The description of the rule.
eventBusName?	`string`	The name or ARN of the event bus associated with the rule.
eventPattern?	`any`	The event pattern of the rule.
name?	`string`	The name of the rule.
roleArn?	`string`	The Amazon Resource Name (ARN) of the role that is used for target invocation.
scheduleExpression?	`string`	The scheduling expression.
state?	`string`	The state of the rule.
targets?	`IResolvable` `\|` `IResolvable` `\|` `TargetProperty[]`	Adds the specified targets to the specified rule, or updates the targets if they are already associated with the rule.
static CFN_RESOURCE_TYPE_NAME	`string`	The CloudFormation resource type name for this resource class.

attrArn

Type: string

The ARN of the rule, such as arn:aws:events:us-east-2:123456789012:rule/example .

cfnOptions

Type: ICfnResourceOptions

Options for this resource, such as condition, update policy etc.

cfnProperties

Type: { [string]: any }

cfnResourceType

Type: string

AWS resource type.

creationStack

Type: string[]

logicalId

Type: string

The logical ID for this CloudFormation stack element.

The logical ID of the element is calculated from the path of the resource node in the construct tree.

To override this value, use overrideLogicalId(newLogicalId).

node

Type: Node

The tree node.

ref

Type: string

Return a string that will be resolved to a CloudFormation { Ref } for this element.

If, by any chance, the intrinsic reference of a resource is not a string, you could coerce it to an IResolvable through Lazy.any({ produce: resource.ref }).

stack

Type: Stack

The stack in which this element is defined.

CfnElements must be defined within a stack scope (directly or indirectly).

description?

Type: string (optional)

The description of the rule.

eventBusName?

Type: string (optional)

The name or ARN of the event bus associated with the rule.

eventPattern?

Type: any (optional)

The event pattern of the rule.

name?

Type: string (optional)

The name of the rule.

roleArn?

Type: string (optional)

The Amazon Resource Name (ARN) of the role that is used for target invocation.

scheduleExpression?

Type: string (optional)

The scheduling expression.

state?

Type: string (optional)

The state of the rule.

targets?

Type: IResolvable | IResolvable | TargetProperty[] (optional)

Adds the specified targets to the specified rule, or updates the targets if they are already associated with the rule.

static CFN_RESOURCE_TYPE_NAME

Type: string

The CloudFormation resource type name for this resource class.

Methods

Name	Description
addDeletionOverride(path)	Syntactic sugar for `addOverride(path, undefined)`.
addDependency(target)	Indicates that this resource depends on another resource and cannot be provisioned unless the other resource has been successfully provisioned.
addDependsOn(target)⚠️	Indicates that this resource depends on another resource and cannot be provisioned unless the other resource has been successfully provisioned.
addMetadata(key, value)	Add a value to the CloudFormation Resource Metadata.
addOverride(path, value)	Adds an override to the synthesized CloudFormation resource.
addPropertyDeletionOverride(propertyPath)	Adds an override that deletes the value of a property from the resource definition.
addPropertyOverride(propertyPath, value)	Adds an override to a resource property.
applyRemovalPolicy(policy?, options?)	Sets the deletion policy of the resource based on the removal policy specified.
getAtt(attributeName, typeHint?)	Returns a token for an runtime attribute of this resource.
getMetadata(key)	Retrieve a value value from the CloudFormation Resource Metadata.
inspect(inspector)	Examines the CloudFormation resource and discloses attributes.
obtainDependencies()	Retrieves an array of resources this resource depends on.
obtainResourceDependencies()	Get a shallow copy of dependencies between this resource and other resources in the same stack.
overrideLogicalId(newLogicalId)	Overrides the auto-generated logical ID with a specific ID.
removeDependency(target)	Indicates that this resource no longer depends on another resource.
replaceDependency(target, newTarget)	Replaces one dependency with another.
toString()	Returns a string representation of this construct.
protected renderProperties(props)

addDeletionOverride(path)

public addDeletionOverride(path: string): void

Parameters

path string — The path of the value to delete.

Syntactic sugar for addOverride(path, undefined).

addDependency(target)

public addDependency(target: CfnResource): void

Parameters

target CfnResource

Indicates that this resource depends on another resource and cannot be provisioned unless the other resource has been successfully provisioned.

This can be used for resources across stacks (or nested stack) boundaries and the dependency will automatically be transferred to the relevant scope.

addDependsOn(target)⚠️

public addDependsOn(target: CfnResource): void

⚠️ Deprecated: use addDependency

Parameters

target CfnResource

Indicates that this resource depends on another resource and cannot be provisioned unless the other resource has been successfully provisioned.

addMetadata(key, value)

public addMetadata(key: string, value: any): void

Parameters

key string
value any

Add a value to the CloudFormation Resource Metadata.

Note that this is a different set of metadata from CDK node metadata; this metadata ends up in the stack template under the resource, whereas CDK node metadata ends up in the Cloud Assembly.](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/metadata-section-structure.html

Note that this is a different set of metadata from CDK node metadata; this metadata ends up in the stack template under the resource, whereas CDK node metadata ends up in the Cloud Assembly.)

addOverride(path, value)

public addOverride(path: string, value: any): void

Parameters

path string — - The path of the property, you can use dot notation to override values in complex types.
value any — - The value.

Adds an override to the synthesized CloudFormation resource.

To add a property override, either use addPropertyOverride or prefix path with "Properties." (i.e. Properties.TopicName).

If the override is nested, separate each nested level using a dot (.) in the path parameter. If there is an array as part of the nesting, specify the index in the path.

To include a literal . in the property name, prefix with a \. In most programming languages you will need to write this as "\\." because the \ itself will need to be escaped.

For example,

cfnResource.addOverride('Properties.GlobalSecondaryIndexes.0.Projection.NonKeyAttributes', ['myattribute']);
cfnResource.addOverride('Properties.GlobalSecondaryIndexes.1.ProjectionType', 'INCLUDE');

would add the overrides

"Properties": {
  "GlobalSecondaryIndexes": [
    {
      "Projection": {
        "NonKeyAttributes": [ "myattribute" ]
        ...
      }
      ...
    },
    {
      "ProjectionType": "INCLUDE"
      ...
    },
  ]
  ...
}

The value argument to addOverride will not be processed or translated in any way. Pass raw JSON values in here with the correct capitalization for CloudFormation. If you pass CDK classes or structs, they will be rendered with lowercased key names, and CloudFormation will reject the template.

addPropertyDeletionOverride(propertyPath)

public addPropertyDeletionOverride(propertyPath: string): void

Parameters

propertyPath string — The path to the property.

Adds an override that deletes the value of a property from the resource definition.

addPropertyOverride(propertyPath, value)

public addPropertyOverride(propertyPath: string, value: any): void

Parameters

propertyPath string — The path of the property.
value any — The value.

Adds an override to a resource property.

Syntactic sugar for addOverride("Properties.<...>", value).

applyRemovalPolicy(policy?, options?)

public applyRemovalPolicy(policy?: RemovalPolicy, options?: RemovalPolicyOptions): void

Parameters

policy RemovalPolicy
options RemovalPolicyOptions

Sets the deletion policy of the resource based on the removal policy specified.

The Removal Policy controls what happens to this resource when it stops being managed by CloudFormation, either because you've removed it from the CDK application or because you've made a change that requires the resource to be replaced.

The resource can be deleted (RemovalPolicy.DESTROY), or left in your AWS account for data recovery and cleanup later (RemovalPolicy.RETAIN). In some cases, a snapshot can be taken of the resource prior to deletion (RemovalPolicy.SNAPSHOT). A list of resources that support this policy can be found in the following link:

getAtt(attributeName, typeHint?)

public getAtt(attributeName: string, typeHint?: ResolutionTypeHint): Reference

Parameters

attributeName string — The name of the attribute.
typeHint ResolutionTypeHint

Returns

Reference

Returns a token for an runtime attribute of this resource.

Ideally, use generated attribute accessors (e.g. resource.arn), but this can be used for future compatibility in case there is no generated attribute.

getMetadata(key)

public getMetadata(key: string): any

Parameters

key string

Returns

any

Retrieve a value value from the CloudFormation Resource Metadata.

Note that this is a different set of metadata from CDK node metadata; this metadata ends up in the stack template under the resource, whereas CDK node metadata ends up in the Cloud Assembly.)

inspect(inspector)

public inspect(inspector: TreeInspector): void

Parameters

inspector TreeInspector — tree inspector to collect and process attributes.

Examines the CloudFormation resource and discloses attributes.

obtainDependencies()

public obtainDependencies(): Stack &#124; CfnResource[]

Returns

Stack | CfnResource[]

Retrieves an array of resources this resource depends on.

This assembles dependencies on resources across stacks (including nested stacks) automatically.

obtainResourceDependencies()

public obtainResourceDependencies(): CfnResource[]

Returns

CfnResource[]

Get a shallow copy of dependencies between this resource and other resources in the same stack.

overrideLogicalId(newLogicalId)

public overrideLogicalId(newLogicalId: string): void

Parameters

newLogicalId string — The new logical ID to use for this stack element.

Overrides the auto-generated logical ID with a specific ID.

removeDependency(target)

public removeDependency(target: CfnResource): void

Parameters

target CfnResource

Indicates that this resource no longer depends on another resource.

This can be used for resources across stacks (including nested stacks) and the dependency will automatically be removed from the relevant scope.

replaceDependency(target, newTarget)

public replaceDependency(target: CfnResource, newTarget: CfnResource): void

Parameters

target CfnResource — The dependency to replace.
newTarget CfnResource — The new dependency to add.

Replaces one dependency with another.

toString()

public toString(): string

Returns

string

Returns a string representation of this construct.

protected renderProperties(props)

protected renderProperties(props: { [string]: any }): { [string]: any }

Parameters

props { [string]: any }

Returns

{ [string]: any }