调试异步瀑布 AWS Lambda

Question

I am writing a lambda for converting images and I am using async.waterfall for it. I am having a hard time debugging the lambda, since it does not seem to start the second function transform. Can any body help me on debugging. This is actually a pretty basic setup but I don't see why it does not go into the transform function nor throws any errors

    async.waterfall([
        function download(next) {
            
            s3.getObject({
                    Bucket: srcBucket,
                    Key: srcKey
                },
                next);
        },
        function transform(response, next) {
            console.log("transform", response);
            sharp(response.Body)
                .webp()
                .toBuffer(next);
        },
        function upload(data, info, next) {
            console.log("upload");
            s3.putObject({
                    Bucket: dstBucket,
                    Key: dstKey,
                    Body: data,
                },
                next);
        }
    ], function (err) {
        if (err) {
            console.error(
                'Unable to convert ' + srcBucket + '/' + srcKey +
                ' and upload to ' + dstBucket + '/' + dstKey +
                ' due to an error: ' + err
            );
        } else {
            console.log(
                'Successfully converted ' + srcBucket + '/' + srcKey +
                ' and uploaded to ' + dstBucket + '/' + dstKey
            );
        }
        callback(null, "message");
    });

Answer 1

If you are using AWS SAM, then you can start the lambda environment locally. Look at the possible options available here . Invoking the code locally can help you debug the code.