AWS CloudFormation .NET Lambda CustomResource Template

Use this .NET Core Lambda template to provision AWS resources that isn't natively supported by CloudFormation.

  CfnResponse cfn = new CfnResponse();
  string result = "";

  //Define a class of you choice and populate it with return values to the callback Url
  var Data = new ResponseData() { SomeParam1 = "someValue" };

  if (input["RequestType"].ToString() == CfnResponse.RequestType_Create)
  {
      //Write resource provisioning code here
      result = cfn.Send(input, context, OpsStatus.Success, Data);
      
      //Signal the call back function with the status "FAILED", if the resource provision errored out\failed
      //result = cfn.Send(input, context, OpsStatus.Fail, Data);
  }
  else if (input["RequestType"].ToString() == CfnResponse.RequestType_Update)
  {
      //Write resource updation code here
      result = cfn.Send(input, context, OpsStatus.Success, Data);
      
      //Signal the call back function with the status "FAILED", if the resource provision errored out\failed
      //result = cfn.Send(input, context, OpsStatus.Fail, Data);
  }
  else if (input["RequestType"].ToString() == CfnResponse.RequestType_Delete)
  {
      //Write resource deletion code here
      result = cfn.Send(input, context, OpsStatus.Success, Data);
      
      //Signal the call back function with the status "FAILED", if the resource provision errored out\failed
      //result = cfn.Send(input, context, OpsStatus.Fail, Data);
  }

How Clouformation calls lambda.

Cloudformation invokes lambda function with a set of parameters, of which one is S3 presigned callback Url called "ResponseURL". This needs to be invoked after the function completes the resource provisioning. The CfnResponse class included in the template takes care of this.