Bedrock Prompt Management: Only allowing 1 prompt variant per prompt

[jantmer]

Describe the bug

Trying to deploy a prompt with 2 variants and getting an error that it only expected 1 variant.

Expected Behavior

According to the construct definition: https://github.com/awslabs/generative-ai-cdk-constructs/blob/main/src/cdk-lib/bedrock/prompts/prompt.ts

It should allow a maximum of 3 variants.

Current Behavior

Getting the following error:

❌ PromptManagerStack failed: Error: The stack named PromptManagerStack failed creation, it may need to be manually deleted from the AWS console: ROLLBACK_COMPLETE: Properties validation failed for resource flightParametersPromptE31C7D46 with message:
[#/Variants: expected maximum item count: 1, found: 2]

Reproduction Steps

Code:
`from aws_cdk import (
Stack
)
from cdklabs.generative_ai_cdk_constructs import (
bedrock
)
from constructs import Construct
import os

class PromptManagerStack(Stack):

def load_text(self, file_name):
    try:
        current_dir = os.path.dirname(os.path.abspath(__file__))
        absolute_path = os.path.join(current_dir, "..", "prompts", file_name)
        with open(absolute_path, "r") as file:
            return file.read()
    except FileNotFoundError:
        raise FileNotFoundError(f"Could not find prompt file at {absolute_path}. Please verify the file exists and the path is correct.")

def __init__(self, scope: Construct, construct_id: str, **kwargs) -> None:
    super().__init__(scope, construct_id, **kwargs)

    #Bedrock Prompt Management - Flight Parameters Prompt

    # For regions and models that require Cross Region Inference, we must create an inference profile
    cris_nova_micro = bedrock.CrossRegionInferenceProfile.from_config(
            geo_region= bedrock.CrossRegionInferenceProfileRegion.US,
            model= bedrock.BedrockFoundationModel.AMAZON_NOVA_MICRO_V1
            )
    
    flightParametersText = self.load_text("flightParameters.txt")
    flightParameters2Text = self.load_text("flightParameters2.txt")
    
    #Create a prompt version with version1 of prompt with Haiku3 - best accuracy       
    flightParametersV1 = bedrock.PromptVariant.text(
        variant_name="V1-Haiku3",
        model=bedrock.BedrockFoundationModel.ANTHROPIC_CLAUDE_HAIKU_V1_0,
        prompt_variables=["customer_name", "current_date", "conversation_history", "language", "station_mapping"],
        prompt_text= flightParametersText,
        inference_configuration={
            "temperature": 0.0,
            "top_p": 0.999,
            "max_tokens": 500,
        }
    )
    
    #Create a prompt version the second version of prompt and Nova Micro - best latency       
    flightParametersV2 = bedrock.PromptVariant.text(
        variant_name="V2-Nova-Micro",
        model=cris_nova_micro,
        prompt_variables=["customer_name", "current_date", "conversation_history", "language", "station_mapping"],
        prompt_text= flightParameters2Text,
        inference_configuration={
            "temperature": 0.0,
            "top_p": 0.999,
            "max_tokens": 500,
        }
    )

    # Define the actual prompt with the different associated versions, and a default version. When running the inference you can decide which version to use.
    flightParametersPrompt = bedrock.Prompt(
        self,
        "flightParameters Prompt",
        prompt_name="FlightParameters",
        description="Prompt for extracting api parameters for flight search from conversation with customer.",
        default_variant=flightParametersV2,
        variants=[flightParametersV1, flightParametersV2]
    )

`

Possible Solution

No response

Additional Information/Context

No response

CDK CLI Version

2.175.1

Framework Version

v0.1.293

Node.js Version

v20.17.0

OS

macos Sonoma

Language

Python

Language Version

3.13.1

Region experiencing the issue

us-west-2

Code modification

N/A

Other information

No response

Service quota

• I have reviewed the service quotas for this construct

[aws-rafams]

Thank you Jaime for raising this issue. Will look into it ASAP.

[aws-rafams]

Managed to reproduce the error. Seems like the rendered CloudFormation code from CDK is syntactically correct but not accepted by CloudFormation (runtime error rather than synth error). Will dive deeper.

[aws-rafams]

Seems like a CloudFormation Problem (regression) that might have been introduced lately due to the change of the specification to include CachePointBlock.