Problem installing PyODBC for local debugging with AWS SAM CLI

Question

I'm developing a lambda function in Python. The function access RDS database using the pyodbc library. To work with the library I'm using layers. My SAM template looks like this and everything works fine while deployed to AWS.

Resources:

    # ODBC Lambda Layer
    PyODBCLayer:
      Type: AWS::Serverless::LayerVersion
      Properties:
        ContentUri: pyodbc_layer.zip

    # Lambda function
    TaskIDFunction:
        Type: AWS::Serverless::Function
        Properties:
            CodeUri: taskid/
            Handler: app.lambda_handler
            Layers:
              - !Ref PyODBCLayer
            Role: !GetAtt TaskIDFunctionIamRole.Arn
            Runtime: python3.6
            Environment:
              Variables:
                ODBCINI: /opt/bin/odbcinst.ini
                ODBCSYSINI: /opt/bin
            Events:
              SendTaskID:
                Type: Api 
                Properties:
                      Path: /task/{id}
                      Method: get

The problem begins when I'm trying to run this locally with sam build && sam local invoke -d 5890 TaskIDFunction --event myEvent.json

I'm getting error message Unable to import module 'app': No module named 'pyodbc' which I understand and typically the solution would be to add pyodbc to requiremens.txt file for local debugging.

However, after I have done that, the sam build command fails with the following message

Build Failed
Error: PythonPipBuilder:ResolveDependencies - {pyodbc==4.0.26(wheel)}

I can pip install pyodbc without problems but for some reason, sam build fails.

I have tried various combinations with removing the layer from the template and installing PyODBC manually to get this running locally but no success.

Answer 1

I dont have reputation enough to comment, so:

Im getting the same error. Wondering if you could evolve this, and if so, how did you do it?

Answer 2

For local debugging, you need to extract the contents of zip file and reference the file path for the layer.

I created a folder called lambda-layers and extracted the zip file contents inside the folder

give the folder path in template.yaml file

modify your template.yaml file to