Serverless WSGI and API Gateway in CDK (and Flask)

[BwL1289]

Documenting this here in case someone else comes across this! Thank you again to @logandk for his help resolving this (and for creating this wonderful library).

If you are using serverless-wsgi as a library (not the plugin), and you are trying to make it work with AWS API Gateway in CDK, you will need to set the API_GATEWAY_BASE_PATH environment variable manually in your code.

For example, if you set the path_part to v1

api_gateway.root.add_resource(path_part="v1")

You need to do:

app = create_app()

os.environ["API_GATEWAY_BASE_PATH"] = "v1"

def handler(event, context):
    return serverless_wsgi.handle_request(app, event, context) 

This way, the serverless_wsgi library parses the api gateway URL correctly. The value you set this env var to needs to be exactly the same as what you pass to to path_part in CDK.

If you do not set the env var, you will see an error like: 404: The requested URL was not found on the server. If you entered the URL manually please check your spelling and try again.

Cheers!