Return FilesystemID after cloudformation stack deployment complete

Question

i am trying to create efs filesystem using cloudformation template inside lambda using boto3. And interested to return output as Filesystemid from stack using describe_stack. however i am getting null values in return. please suggest where i am making mistake.

error is:

Response
null

Code is:

import boto3
import time
import json
import botocore

datetime = time.strftime("%Y%m%d%H%M%S")
stackname = 'My-EFS'
region = "ap-south-1"
client = boto3.client('cloudformation')
s = boto3.Session(region_name=region)


def lambda_handler(event, context):

    response = client.create_stack(
      StackName= stackname,
      TemplateURL='https://cloudnaeem.s3.amazonaws.com/efs.yaml',
      
    )
    waiter = client.get_waiter('stack_create_complete')
    res = waiter.wait(
            StackName=stackname,
        )
     
    stack = client.describe_stacks(StackName=stackname)
    FileSystem_id=None
    
    for v in stack["Stacks"][0]["Outputs"]:
        if v["OutputKey"] == "FileSystemId":
            FileSystem_id = v["OutputValue"]
    
    return FileSystem_id

template output is :

Outputs:
  EFS:
    Description: The created EFS 
    Value: !Ref EFSFileSystem

Answer 1

Your output is called EFS but you are looking for FileSystemId. Your code should be thus:

    for v in stack["Stacks"][0]["Outputs"]:
        if v["OutputKey"] == "EFS":
            FileSystem_id = v["OutputValue"]