Async aioboto3 from lambda

app.py

import asyncio
import aioboto3

session = aioboto3.Session()

async def main():
    async with session.client("ec2") as ec2:
        tasks = await asyncio.gather(
            ec2.describe_regions(),
            ec2.describe_instances()
        )
        return len(tasks[0]["Regions"]), len(tasks[1]["Reservations"])


def lambda_handler(event, context):
    return asyncio.run(main())

requirements.txt

aioboto3

template.yml

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31

Globals:
  Function:
    Timeout: 30
    MemorySize: 128

Resources:
  DocumentLambdaFunction:
    Type: AWS::Serverless::Function
    Properties:
      FunctionName: DocumentLambdaFunction
      CodeUri: DocumentLambdaFunction/
      Handler: app.lambda_handler
      Runtime: python3.9
      Policies:
        - EC2DescribePolicy: {}