SAM CLI for running Lambda functions locally fails when building docker image with x86_64 problem - aws-lambda

Question

Host Machine: Mac M1
SAM version: 1.70.0
CDK version: 2.60.0 (build 2d40d77)
In our api_stack.py file we have a simple setup of
API Gateway REST endpoints
Lambda functions triggered by API Gateway
The entire codebase was initially setup with cdk init
When we run cdk synth, we get a files generated in the folder cdk.out including the api.template.json which is the CloudFormation template file.
Following commands all work:
cdk synth
cdk deploy
However when we run sam local invoke or sam local start-api, I get an error that looks like below.
% sam local invoke GetUserTemporary -t cdk.out/api.template.json -e events/get_user/prod-user.json
Invoking get_user_temporary.handler.handle (python3.9)
DependenciesLayerDF300E31 is a local Layer in the template
Local image was not found.
Building image.......................................................................................................................................................................................................................................................................................................................
Failed to build Docker Image
NoneType: None
Error: Error building docker image: The command '/bin/sh -c mv /var/rapid/aws-lambda-rie-x86_64 /var/rapid/aws-lambda-rie && chmod +x /var/rapid/aws-lambda-rie' returned a non-zero code: 1
This used to work just about 1 week ago and now it is showing this error all of sudden. Exact same codebase is git cloned in my co-workers' machines.
Windows
Mac M1
And this all works for them. I try to do this in my M1 laptop and it fails now.

Answer 1

It turns out you have to specifically specify what architecture you are using when defining your lambda functions in your CDK Python source code. You can achieve this by adding the architecture= argument like below.
fn = _lambda.Function(
self,
func_name,
runtime=_lambda.Runtime.PYTHON_3_9,
code=_lambda.Code.from_asset('api/lambda_fns'),
handler=f'{func_path}.handle',
layers=[self.layer],
role=role,
architecture=_lambda.Architecture.X86_64,
)