Menu
Sign In to the Console
AWS CloudFormation
User Guide (API Version 2010-05-15)

AWS Documentation » AWS CloudFormation » User Guide » Template Reference » AWS Resource Types Reference » AWS::Lambda::EventSourceMapping

AWS::Lambda::EventSourceMapping

The AWS::Lambda::EventSourceMapping resource specifies a stream as an event source for an AWS Lambda (Lambda) function. The stream can be an Kinesis stream or an Amazon DynamoDB (DynamoDB) stream. Lambda invokes the associated function when records are posted to the stream. For more information, see CreateEventSourceMapping in the AWS Lambda Developer Guide.

Syntax

To declare this entity in your AWS CloudFormation template, use the following syntax:

JSON

{
  "Type" : "AWS::Lambda::EventSourceMapping",
  "Properties" : {
    "BatchSize" : Integer,
    "Enabled" : Boolean,
    "EventSourceArn" : String,
    "FunctionName" : String,
    "StartingPosition" : String
  }
}

YAML

Type: "AWS::Lambda::EventSourceMapping"
Properties: 
  BatchSize: Integer
  Enabled: Boolean
  EventSourceArn: String
  FunctionName: String
  StartingPosition: String

Properties

BatchSize

The largest number of records that Lambda retrieves from your event source when invoking your function. Your function receives an event with all the retrieved records. For the default and valid values, see CreateEventSourceMapping in the AWS Lambda Developer Guide.

Required: No

Type: Integer

Update requires: No interruption

Enabled

Indicates whether Lambda begins polling the event source.

Required: No

Type: Boolean

Update requires: No interruption

EventSourceArn

The Amazon Resource Name (ARN) of the Kinesis or DynamoDB stream that is the source of events. Any record added to this stream can invoke the Lambda function. For more information, see CreateEventSourceMapping in the AWS Lambda Developer Guide.

Required: Yes

Type: String

Update requires: Replacement

FunctionName

The name or ARN of a Lambda function to invoke when Lambda detects an event on the stream.

Required: Yes

Type: String

Update requires: No interruption

StartingPosition

The position in the stream where Lambda starts reading. For valid values, see CreateEventSourceMapping in the AWS Lambda Developer Guide.

Required: Yes

Type: String

Update requires: Replacement

Return Values

Ref

When the logical ID of this resource is provided to the Ref intrinsic function, Ref returns the resource name.

For more information about using the Ref function, see Ref.

Example

The following example associates an Kinesis stream with a Lambda function.

JSON

"EventSourceMapping": {  
  "Type": "AWS::Lambda::EventSourceMapping",
  "Properties": {
    "EventSourceArn" : { "Fn::Join" : [ "", [ "arn:aws:kinesis:", { "Ref" : "AWS::Region" }, ":", { "Ref" : "AWS::AccountId" }, ":stream/", { "Ref" : "KinesisStream" }] ] },
    "FunctionName" : { "Fn::GetAtt" : ["LambdaFunction", "Arn"] },
    "StartingPosition" : "TRIM_HORIZON"
  }
}

YAML

EventSourceMapping: 
  Type: "AWS::Lambda::EventSourceMapping"
  Properties: 
    EventSourceArn: 
      Fn::Join: 
        - ""
        - 
          - "arn:aws:kinesis:"
          - 
            Ref: "AWS::Region"
          - ":"
          - 
            Ref: "AWS::AccountId"
          - ":stream/"
          - 
            Ref: "KinesisStream"
    FunctionName: 
      Fn::GetAtt: 
        - "LambdaFunction"
        - "Arn"
    StartingPosition: "TRIM_HORIZON"