Terraform For Using AWS Lambda With Amazon Lex

I have been having some trouble trying to get the fulfillment_activity codehook to work so that I can use Lambda Functions for the backend. For some reason, I am getting this error message from Terraform.

Error: error waiting for Lex Bot (helloBot) create: unexpected state 'FAILED', wanted target 'NOT_BUILT, READY, READY_BASIC_TESTING'. last error: Intent 'sample_intent' has an invalid message version defined for its fulfillment.

Here is my Terraform config:

# AWS Lex Bot
resource "aws_lex_bot" "helloBot" {
  depends_on = [ aws_lex_intent.sample_intent ]
  locale                      = "en-US"
  name                        = "helloBot"
  process_behavior            = "BUILD"
  voice_id                    = "Salli"
  create_version              = true
  idle_session_ttl_in_seconds = 300
  child_directed              = false

  abort_statement {
    message {
      content      = "Abort Abort!"
      content_type = "PlainText"
    }
  }

  clarification_prompt {
    max_attempts = 2

    message {
      content      = "No Idea What You're Saying!"
      content_type = "PlainText"
    }
  }

  intent {
    intent_name    = "sampleIntentName"
    intent_version = aws_lex_intent.sample_intent.version
  }
}

resource "aws_lambda_permission" "lex_sample_intent_lambda" {
  statement_id  = "AllowExecutionFromAmazonLex"
  action        = "lambda:InvokeFunction"
  function_name = "someLambdaFunctionName"
  principal     = "lex.amazonaws.com"

  # https://docs.aws.amazon.com/lex/latest/dg/gs-cli-update-lambda.html
  source_arn = "arn:aws:lex:myRegion:accountId:intent:sampleIntentName:*"
}

# AWS Lex Intents
data "aws_lambda_function" "existing" {
  function_name = "someLambdaFunctionName"
  qualifier     = "dev"
}

resource "aws_lex_intent" "sample_intent" {
  create_version = true
  name           = "sampleIntentName"

  fulfillment_activity {
    type = "CodeHook"
    code_hook {
      message_version = "1.0"
      uri             = data.aws_lambda_function.existing.qualified_arn
    }
  }

  sample_utterances = [
    "hi",
    "hello"
  ]
}

I looked at the cli documentation and it appears that we are supposed to use "1.0" for the message version.

It looks like the Terraform configuration should be correct. The problem was related to the data type of the message version when it was a variable. It was incorrectly set as a number instead of a string.