Amazon lambda does not show python logs

Question

My API(Python) is deployed on Amazon Lambda. The problem is when I request my API I get the internal server error. I can tail the Lambda logs but I don't see the actual error or stack trace where the code crashed. When I tail the logs I just get the following output.

START RequestId: 62341bgd-6231-11e8-8c5b-25793532a32u Version: $LATEST
END RequestId: 62341b0d-6231-1128-8r5b-2b793032a3ed
REPORT RequestId: 6234te0b-6rte-aaa8-au5a-21t93132r3rt  Duration: 0.46 ms

How can I see the actual stack trace of my python api for debugging?

Answer 1

Lambda always tries to write the Python stack trace to CloudWatch. Make sure your function has the required permissions:

    {
        "Effect": "Allow",
        "Action": [
            "logs:CreateLogStream",
            "logs:PutLogEvents"
        ],
        "Resource": "arn:aws:logs:eu-west-1:123456789012:*"
    },
    {
        "Effect": "Allow",
        "Action": "logs:CreateLogGroup",
        "Resource": "*"
    }

Answer 2

If you are using Lambda_basic_execution role, simple print in python will show logs in cloudwatch.