I can’t for the life of me understand how I would set up SAM to run my Typescript/nodejs api locally.

I run sam local start-api and everything kind of starts up. Lots and lots of debug logging that doesn’t tell me anything. Once I try to invoke the API endpoint with CURL I get the following error message:

26 Apr 2024 00:43:22,108 [ERROR] (rapid) Init failed error=Runtime exited with error: exit status 129 InvokeID=
26 Apr 2024 00:43:22,109 [ERROR] (rapid) Invoke failed error=Runtime exited with error: exit status 129 InvokeID=3506a416-5cd1-42a3-ba56-45ffa76d2369
26 Apr 2024 00:43:22,110 [ERROR] (rapid) Invoke DONE failed: Sandbox.Failure

Here’s an example of how I set up a lambda function in the SAM template yaml:

  GetAuthenticatedUserDetailsFunction:
      CodeUri: ../
      Handler: GetAuthenticatedUserDetails.lambdaHandler
      Events:
        GetAuthenticatedUserDetails:
          Type: Api 
          Properties:
            RestApiId: !Ref api
            Path: /gaud
            Method: get
      Policies:
        - Version: '2012-10-17' 
          Statement:
            - Effect: Allow
              Action: "rds-db:connect"
              Resource: !Sub 'arn:aws:rds-db:${AWS::Region}:${AWS::AccountId}:dbuser:${DBProxyPRXID}/*'
    Metadata:
      BuildMethod: esbuild
      BuildProperties:
        Minify: true
        Target: es2020
        Sourcemap: true
        EntryPoints:
        - src/GetAuthenticatedUserDetails.ts

What am I doing wrong? I thought the sam cli would be smart enough to figure all this out by itself?

Here are some things that I already know

• Entrypoints attribute contains the “src” directory. If I move that dir to the CodeUri attribute then sam build fails by saying that esbuild doesn’t exist on my machine (but magically does exist with this config)
• The sam build command transpiles all the .ts code to .js dirs in the ./aws-sam directory. But! It has a different structure where the code is compiled per function.

I understand that the error points to the fact that sam local can’t find the function in whatever directory it is looking in. The Typescript code is transpiled into a .aws-sam/ directory that has a completely different structure (I assume it’s self contained and will be zipped up for deployment).

I did try to hack the CodeUri attribute to point to the .aws-sam directory