README.md

#S3-Event-Notifier Cloudformation Custom Resource for S3 Event Notification with Lambda

Input:

#required
S3Bucket: Bucketname which the event should be added to 
S3Event: The S3 bucket event for which to invoke the Lambda function. For more information, see Supported Event Types in the Amazon Simple Storage Service Developer Guide.
EventLambdaArn: The Amazon Resource Name (ARN) of the Lambda function that Amazon S3 invokes when the specified event type occurs.             

#optional:
S3Prefix: prefix event filter (something like /myapp/static)
S3Suffix: suffix event filter (something like .img)

Permission:

S3 must be allowed to call the custom resource lambda function. EventLambda must be allowed to access S3 Bucket. Which permission should be used is use case depended. For more information see: https://docs.aws.amazon.com/lambda/latest/dg/with-s3.html

Example

Use custom resource:

S3EventNotifierCustomResource: 
  Type: "Custom::S3EventNotifier"
  Properties: 
    ServiceToken:
      !Sub |
        arn:aws:lambda:${AWS::Region}:${AWS::AccountId}:function:${LambdaFunctionName}
    S3Event: 's3:ObjectCreated:*'
    S3Bucket: my-bucket
    S3Prefix: this/is/an/example/path
    S3Suffix: "*.png"
    EventLambdaArn: GetAtt(EventLambda,'Arn')
    StackName: 
      Ref: "StackName"      

Limitations

Currently only on S3Event can be set.

Simultaneous creation of S3 event notification on the same bucket leads to crashes of the cloudformation template. Workaround: build a chain with DependsOn method to ensure that S3-Event-Notifier will be called sequential.