Fallback to original images

[roberto-meaningfulgigs]

Hey,

I've been using this project as our image resizer tool and one issue I sometimes have is the JSON error response for some bad conversion, unsupported image by sharp or something like this, and I don't want to show this error for enduser.

I see the fallback default image, but what I need is to just return the original image (or file) and log this error for ourselves - so user still have access to the file and we don't show broken images.

I did this change in my fork and I'm already using it, let me know if this idea makes sense for a pull request.

[dougtoppin]

@roberto-meaningfulgigs This is an interesting idea. There may be some occasions where returning the original image on an error may not be appropriate. An example might be a content check with a blur edit. What to return may depend on the cause of the error and what operations were in the request.
In your use case, did you check on what the error cause was?
Having a configuration parameter might be useful where a deployment can set the behavior of error handling. This would give the most flexibility in usage.

We will discuss this and let you know.

[roberto-meaningfulgigs]

@dougtoppin Lambda was returning:

RequestId: 9e16a21e-4143-4e30-ac9d-b601f95c05ac Error: Runtime exited with error: signal: bus error
Runtime.ExitError

And now it is working without any change. This already happened before, but since I can't reproduce it anytime I couldn't enable DEBUG or something like this.

For the case of adding as a parameter, this is basically what I already did:
https://github.com/aws-solutions/serverless-image-handler/compare/main...MeaningfulGigs:serverless-image-handler:feature/fallback-original?expand=1
I even included unit test so I could test before pushing to my env, if you think it's fine to open the PR I can re-check if I'm not missing any other change for an extra parameter too.

Thanks!