Meaning of CommonRunTimeError 0?

[ramink]

Hi,

I've recently begun experimenting with the AWS SDK, and managed to get the Buckets example app working.

I made my own app that does the equivalent, and that works too. Then I've tried to extend it to query DynamoDB for some data that I've created using the AWS web console. That code is based on the SDK examples for DynamoDB. I'm pretty sure (but not 100%, of course) that I've set up my Roles and Permissions correctly for this to work, but when I run my code, I get an exception when calling dynamoDB.getItem.

The error isn't very helpful, as its localizedDescription simply says: "The operation couldn't be completed. (AwsCommonRuntimeKit.CommonRunTimeError error 0.)"

As far as I can tell, from chasing this in the debugger, this error state is generated in Orchestrator:execute. But I really don't understand what has gone wrong.

Do you have any suggestions on how to progress from here?

Thanks,
R

[ramink]

Actually, by luck, I think I have discovered the problem. I think it stems from the identityToken given by SignInWithApple having expired (after 24h?). So that's not a very useful error message.

This is a complex stack of software that's still a work in progress, so I don't necessarily expect the errors to be that helpful, but is the experience I've described expected?

Having resolved the SIWA problem, I'm now stuck at another problem with the slightly less cryptic error of: "The operation couldn't be completed. (AWSClientRuntime.UnknownAWSHTTPServiceError error 1.)"

Hmm. Searching through the SDK, it seems likely that this resulting from a call to an httpError somewhere in Sources/Services/AWSDynamoDB/Sources/AWSDynamoDB. At least I have something to go on, here. But any help would be appreciated! Maybe it's a role/permission issue, after all!

[ramink]

And now I have a bit more information! It is GetItemOutputError.httpError that is being called, and the baseError is an AWSClientRuntime.AWSJSONError with code "ValidationException".

[jbelkins]

UnknownAWSHTTPServiceError is returned by the SDK when the AWS service you're calling responds with an error, but it's not an error that the AWS SDK for Swift knows about.

The best way to learn about the cause of this error is to go to the docs for the AWS service you're using and look up the code that you received (in this case, ValidationException.)
https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/CommonErrors.html

The error may also have a message field that elaborates on the exact cause of the error.

[ramink]

Thanks for the response, @jbelkins

Looking at it again, the message field is nil, so no extra clues there. And the code on the CommonErrors page simply says,

The input fails to satisfy the constraints specified by an AWS service.

HTTP Status Code: 400

That's not much of a clue, unfortunately.

I figured it out, eventually. In my code, I had erroneously given GetItem just one key, the sort key, not really thinking too much about how DynamoDB works, hoping that since I only had three records in the table, the sort key was enough to get a unique match. But I tried it with both partition and sort keys, and it now works. Looking more closely at the API docs 😳, I see this is how things are supposed to be.

So all's well that ends well! I am now unstuck, but I do wish the errors could have been more helpful!