This is the new *CloudFormation Template Reference Guide*. Please update your bookmarks and links. For help getting started with CloudFormation, see the [AWS CloudFormation User Guide](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/Welcome.html).
# AWS::Events::Rule
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](https://docs.aws.amazon.com/eventbridge/latest/APIReference/API_DisableRule.html).
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](https://docs.aws.amazon.com/eventbridge/latest/APIReference/API_CreateEventBus.html).
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](https://docs.aws.amazon.com/awsaccountbilling/latest/aboutv2/budgets-managing-costs.html).
**Note**
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](https://docs.aws.amazon.com/eventbridge/latest/userguide/rule-generate-template.html) in the *Amazon EventBridge User Guide*.
## Syntax
To declare this entity in your CloudFormation template, use the following syntax:
### JSON
```
{
"Type" : "AWS::Events::Rule",
"Properties" : {
"[Description](#cfn-events-rule-description)" : String,
"[EventBusName](#cfn-events-rule-eventbusname)" : String,
"[EventPattern](#cfn-events-rule-eventpattern)" : Json,
"[Name](#cfn-events-rule-name)" : String,
"[RoleArn](#cfn-events-rule-rolearn)" : String,
"[ScheduleExpression](#cfn-events-rule-scheduleexpression)" : String,
"[State](#cfn-events-rule-state)" : String,
"[Tags](#cfn-events-rule-tags)" : [ Tag, ... ],
"[Targets](#cfn-events-rule-targets)" : [ Target, ... ]
}
}
```
### YAML
```
Type: AWS::Events::Rule
Properties:
[Description](#cfn-events-rule-description): String
[EventBusName](#cfn-events-rule-eventbusname): String
[EventPattern](#cfn-events-rule-eventpattern): Json
[Name](#cfn-events-rule-name): String
[RoleArn](#cfn-events-rule-rolearn): String
[ScheduleExpression](#cfn-events-rule-scheduleexpression): String
[State](#cfn-events-rule-state): String
[Tags](#cfn-events-rule-tags):
- Tag
[Targets](#cfn-events-rule-targets):
- Target
```
## Properties
`Description`
The description of the rule.
*Required*: No
*Type*: String
*Maximum*: `512`
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)
`EventBusName`
The name or ARN of the event bus associated with the rule. If you omit this, the default event bus is used.
*Required*: No
*Type*: String
*Pattern*: `[/\.\-_A-Za-z0-9]+`
*Minimum*: `1`
*Maximum*: `256`
*Update requires*: [Some interruptions](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-some-interrupt)
`EventPattern`
The event pattern of the rule. For more information, see [Events and Event Patterns](https://docs.aws.amazon.com/eventbridge/latest/userguide/eventbridge-and-event-patterns.html) in the * *Amazon EventBridge User Guide* *.
*Required*: Conditional
*Type*: Json
*Maximum*: `4096`
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)
`Name`
The name of the rule.
*Required*: No
*Type*: String
*Pattern*: `[\.\-_A-Za-z0-9]+`
*Minimum*: `1`
*Maximum*: `64`
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)
`RoleArn`
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.
*Required*: No
*Type*: String
*Minimum*: `1`
*Maximum*: `1600`
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)
`ScheduleExpression`
The scheduling expression. For example, "cron(0 20 \$1 \$1 ? \$1)", "rate(5 minutes)". For more information, see [Creating an Amazon EventBridge rule that runs on a schedule](https://docs.aws.amazon.com/eventbridge/latest/userguide/eb-create-rule-schedule.html).
*Required*: Conditional
*Type*: String
*Maximum*: `256`
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)
`State`
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](https://docs.aws.amazon.com/awscloudtrail/latest/userguide/logging-management-events-with-cloudtrail.html#logging-management-events) in the *CloudTrail User Guide*, and [Filtering management events from AWS services](https://docs.aws.amazon.com/eventbridge/latest/userguide/eb-service-event.html#eb-service-event-cloudtrail) in the * *Amazon EventBridge User Guide* *.
This value is only valid for rules on the [default](https://docs.aws.amazon.com/eventbridge/latest/userguide/eb-what-is-how-it-works-concepts.html#eb-bus-concepts-buses) event bus or [custom event buses](https://docs.aws.amazon.com/eventbridge/latest/userguide/eb-create-event-bus.html). It does not apply to [partner event buses](https://docs.aws.amazon.com/eventbridge/latest/userguide/eb-saas.html).
*Required*: No
*Type*: String
*Allowed values*: `DISABLED | ENABLED | ENABLED_WITH_ALL_CLOUDTRAIL_MANAGEMENT_EVENTS`
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)
`Tags`
Property description not available.
*Required*: No
*Type*: Array of [Tag](aws-properties-events-rule-tag.md)
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)
`Targets`
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](https://docs.aws.amazon.com/eventbridge/latest/userguide/eb-targets.html) 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](https://docs.aws.amazon.com/eventbridge/latest/userguide/auth-and-access-control-eventbridge.html) 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](https://aws.amazon.com/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](https://docs.aws.amazon.com/eventbridge/latest/userguide/eventbridge-cross-account-event-delivery.html) 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](https://docs.aws.amazon.com/eventbridge/latest/APIReference/API_PutPermission.html).
**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.
*Required*: No
*Type*: Array of [Target](aws-properties-events-rule-target.md)
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)
## Return values
### Ref
When you pass the logical ID of this resource to the intrinsic `Ref` function, `Ref` returns event rule ID, such as `mystack-ScheduledRule-ABCDEFGHIJK`.
For more information about using the `Ref` function, see [https://docs.aws.amazon.com/AWSCloudFormation/latest/TemplateReference/intrinsic-function-reference-ref.html](https://docs.aws.amazon.com/AWSCloudFormation/latest/TemplateReference/intrinsic-function-reference-ref.html).
### Fn::GetAtt
####
`Arn`
The ARN of the rule, such as `arn:aws:events:us-east-2:123456789012:rule/example`.
## Examples
**Topics**
+ [Create a cross-Region rule](#aws-resource-events-rule--examples--Create_a_cross-Region_rule)
+ [Create a rule that includes a dead-letter queue for a target](#aws-resource-events-rule--examples--Create_a_rule_that_includes_a_dead-letter_queue_for_a_target)
+ [Regularly invoke Lambda function](#aws-resource-events-rule--examples--Regularly_invoke_Lambda_function)
+ [Invoke Lambda Function in Response to an Event](#aws-resource-events-rule--examples--Invoke_Lambda_Function_in_Response_to_an_Event)
+ [Notify a Topic in Response to a Log Entry](#aws-resource-events-rule--examples--Notify_a_Topic_in_Response_to_a_Log_Entry)
### Create a cross-Region rule
The following example demonstrates how to create a rule that routes events across Regions.
#### JSON
```
{
"Resources": {
"EventRuleRegion1": {
"Type": "AWS::Events::Rule",
"Properties": {
"Description": "Routes to us-east-1 event bus",
"EventBusName": "MyBusName",
"State": "ENABLED",
"EventPattern": {
"source": [
"MyTestApp"
],
"detail": [
"MyTestAppDetail"
]
},
"Targets": [
{
"Arn": "arn:aws:events:us-east-1:123456789012:event-bus/CrossRegionDestinationBus",
"Id": " CrossRegionDestinationBus",
"RoleArn": {
"Fn::GetAtt": [
"EventBridgeIAMrole",
"Arn"
]
}
}
]
}
},
"EventBridgeIAMrole": {
"Type": "AWS::IAM::Role",
"Properties": {
"AssumeRolePolicyDocument": {
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": {
"Service": {
"Fn::Sub": "events.amazonaws.com"
}
},
"Action": "sts:AssumeRole"
}
]
},
"Path": "/",
"Policies": [
{
"PolicyName": "PutEventsDestinationBus",
"PolicyDocument": {
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"events:PutEvents"
],
"Resource": [
"arn:aws:events:us-east-1:123456789012:event-bus/CrossRegionDestinationBus"
]
}
]
}
}
]
}
}
```
#### YAML
```
Resources:
EventRuleRegion1:
Type: 'AWS::Events::Rule'
Properties:
Description: Routes to us-east-1 event bus
EventBusName: MyBusName
State: ENABLED
EventPattern:
source:
- MyTestApp
detail:
- MyTestAppDetail
Targets:
- Arn: >-
arn:aws:events:us-east-1:123456789012:event-bus/CrossRegionDestinationBus
Id: ' CrossRegionDestinationBus'
RoleArn: !GetAtt
- EventBridgeIAMrole
- Arn
EventBridgeIAMrole:
Type: 'AWS::IAM::Role'
Properties:
AssumeRolePolicyDocument:
Version: 2012-10-17
Statement:
- Effect: Allow
Principal:
Service: !Sub events.amazonaws.com
Action: 'sts:AssumeRole'
Path: /
Policies:
- PolicyName: PutEventsDestinationBus
PolicyDocument:
Version: 2012-10-17
Statement:
- Effect: Allow
Action:
- 'events:PutEvents'
Resource:
- >-
arn:aws:events:us-east-1:123456789012:event-bus/CrossRegionDestinationBus
```
### Create a rule that includes a dead-letter queue for a target
The following example demonstrates how to send all EC2 events to an SQS queue, and include a dead-letter queue and retry policy settings for the target of the rule.
#### JSON
```
{
"MyNewEventsRule": {
"Type": "AWS::Events::Rule",
"Properties": {
"Description": "Test Events Rule",
"Name": "mynewabc",
"EventPattern": {
"source": [
"aws.ec2"
]
},
"State": "ENABLED",
"Targets": [
{
"Arn": "arn:aws:sqs:us-west-2:081035103721:demoSQS",
"Id": "Id1234",
"RetryPolicy": {
"MaximumRetryAttempts": 4,
"MaximumEventAgeInSeconds": 400
},
"DeadLetterConfig": {
"Arn": "arn:aws:sqs:us-west-2:081035103721:demoDLQ"
}
}
]
}
}
}
```
#### YAML
```
MyNewEventsRule:
Type: 'AWS::Events::Rule'
Properties:
Description: Test Events Rule
Name: mynewabc
EventPattern:
source:
- aws.ec2
State: ENABLED
Targets:
- Arn: 'arn:aws:sqs:us-west-2:081035103721:demoSQS'
Id: Id1234
RetryPolicy:
MaximumRetryAttempts: 4
MaximumEventAgeInSeconds: 400
DeadLetterConfig:
Arn: 'arn:aws:sqs:us-west-2:081035103721:demoDLQ'
```
### Regularly invoke Lambda function
The following example creates a rule that invokes the specified Lambda function every 10 minutes. The `PermissionForEventsToInvokeLambda` resource grants EventBridge permission to invoke the associated function.
#### JSON
```
"ScheduledRule": {
"Type": "AWS::Events::Rule",
"Properties": {
"Description": "ScheduledRule",
"ScheduleExpression": "rate(10 minutes)",
"State": "ENABLED",
"Targets": [{
"Arn": { "Fn::GetAtt": ["LambdaFunction", "Arn"] },
"Id": "TargetFunctionV1"
}]
}
},
"PermissionForEventsToInvokeLambda": {
"Type": "AWS::Lambda::Permission",
"Properties": {
"FunctionName": { "Ref": "LambdaFunction" },
"Action": "lambda:InvokeFunction",
"Principal": "events.amazonaws.com",
"SourceArn": { "Fn::GetAtt": ["ScheduledRule", "Arn"] }
}
}
```
#### YAML
```
ScheduledRule:
Type: AWS::Events::Rule
Properties:
Description: "ScheduledRule"
ScheduleExpression: "rate(10 minutes)"
State: "ENABLED"
Targets:
-
Arn:
Fn::GetAtt:
- "LambdaFunction"
- "Arn"
Id: "TargetFunctionV1"
PermissionForEventsToInvokeLambda:
Type: AWS::Lambda::Permission
Properties:
FunctionName: !Ref "LambdaFunction"
Action: "lambda:InvokeFunction"
Principal: "events.amazonaws.com"
SourceArn:
Fn::GetAtt:
- "ScheduledRule"
- "Arn"
```
### Invoke Lambda Function in Response to an Event
The following example creates a rule that invokes the specified Lambda function when any EC2 instance's state changes to stopping.
#### JSON
```
"EventRule": {
"Type": "AWS::Events::Rule",
"Properties": {
"Description": "EventRule",
"EventPattern": {
"source": [
"aws.ec2"
],
"detail-type": [
"EC2 Instance State-change Notification"
],
"detail": {
"state": [
"stopping"
]
}
},
"State": "ENABLED",
"Targets": [{
"Arn": { "Fn::GetAtt": ["LambdaFunction", "Arn"] },
"Id": "TargetFunctionV1"
}]
}
},
"PermissionForEventsToInvokeLambda": {
"Type": "AWS::Lambda::Permission",
"Properties": {
"FunctionName": { "Ref": "LambdaFunction" },
"Action": "lambda:InvokeFunction",
"Principal": "events.amazonaws.com",
"SourceArn": { "Fn::GetAtt": ["EventRule", "Arn"] }
}
}
```
#### YAML
```
EventRule:
Type: AWS::Events::Rule
Properties:
Description: "EventRule"
EventPattern:
source:
- "aws.ec2"
detail-type:
- "EC2 Instance State-change Notification"
detail:
state:
- "stopping"
State: "ENABLED"
Targets:
-
Arn:
Fn::GetAtt:
- "LambdaFunction"
- "Arn"
Id: "TargetFunctionV1"
PermissionForEventsToInvokeLambda:
Type: AWS::Lambda::Permission
Properties:
FunctionName:
Ref: "LambdaFunction"
Action: "lambda:InvokeFunction"
Principal: "events.amazonaws.com"
SourceArn:
Fn::GetAtt:
- "EventRule"
- "Arn"
```
### Notify a Topic in Response to a Log Entry
The following example creates a rule that notifies an Amazon Simple Notification Service topic if an AWS CloudTrail log entry contains a call by the root user. The `EventTopicPolicy ` resource grants Amazon EventBridge permission to notify the associated Amazon SNS topic.
#### JSON
```
"OpsEventRule": {
"Type": "AWS::Events::Rule",
"Properties": {
"Description": "EventRule",
"EventPattern": {
"detail-type": [ "AWS API Call via CloudTrail" ],
"detail": {
"userIdentity": {
"type": [ "Root" ]
}
}
},
"State": "ENABLED",
"Targets": [
{
"Arn": { "Ref": "MySNSTopic" },
"Id": "OpsTopic"
}
]
}
}
"EventTopicPolicy": {
"Type": "AWS::SNS::TopicPolicy",
"Properties": {
"PolicyDocument": {
"Statement": [
{
"Effect": "Allow",
"Principal": { "Service": "events.amazonaws.com" },
"Action": "sns:Publish",
"Resource": "*"
}
]
},
"Topics": [ { "Ref": "MySNSTopic" } ]
}
}
```
#### YAML
```
OpsEventRule:
Type: AWS::Events::Rule
Properties:
Description: "EventRule"
EventPattern:
detail-type:
- "AWS API Call via CloudTrail"
detail:
userIdentity:
type:
- "Root"
State: "ENABLED"
Targets:
-
Arn:
Ref: "MySNSTopic"
Id: "OpsTopic"
EventTopicPolicy:
Type: 'AWS::SNS::TopicPolicy'
Properties:
PolicyDocument:
Statement:
- Effect: Allow
Principal:
Service: events.amazonaws.com
Action: 'sns:Publish'
Resource: '*'
Topics:
- !Ref MySNSTopic
```