With the aws sdk version2 for Go S3Client.GetObject() how do I distinguish when the key doesn't exist from other errors?

Question

This should be in the docs but I can't find it anywhere.

I'm using the aws sdk for Go version 2. When I do a s3Client.GetObject(...) and it returns an error I need to distinguish when the key doesn't exist from other errors. The error is a 404 but it is a smithyOperation error and there is no way to check the status code.

How do I distinguish the case where the key does not exist in the S3 bucket from other errors. Here is the code:

out, err := client.GetObject(context.TODO(), &s3.GetObjectInput{
    Bucket: bucketName,
    Key:    key,
})
if err != nil {
 //  Here is where I need to distinguish when the key does not exist from other errors
 ...
 }

Answer 1

It should be an service client error, see https://aws.github.io/aws-sdk-go-v2/docs/handling-errors/

You read them with:

import "log"
import "github.com/aws/smithy-go"

// ...

if err != nil {
    var oe *smithy.OperationError
    if errors.As(err, &oe) {
        log.Printf("failed to call service: %s, operation: %s, error: %v", oe.Service(), oe.Operation(), oe.Unwrap())
    }
    return
}

This should wrap the nosuchkey error as defined in https://docs.aws.amazon.com/AmazonS3/latest/API/API_GetObject.html#API_GetObject_Errors