Converting AWS Error code, checking if match

aws-err-code-conversion.go

// https://docs.aws.amazon.com/sdk-for-go/v1/developer-guide/handling-errors.html

svc := s3.New(sess)
resp, err := svc.GetObject(&s3.GetObjectInput{
    Bucket: aws.String(os.Args[1]),
    Key:    aws.String(os.Args[2]),
})

if err != nil {
    // Casting to the awserr.Error type will allow you to inspect the error
    // code returned by the service in code. The error code can be used
    // to switch on context specific functionality. In this case a context
    // specific error message is printed to the user based on the bucket
    // and key existing.
    //
    // For information on other S3 API error codes see:
    // http://docs.aws.amazon.com/AmazonS3/latest/API/ErrorResponses.html
    if aerr, ok := err.(awserr.Error); ok {
        switch aerr.Code() {
        case s3.ErrCodeNoSuchBucket:
            exitErrorf("bucket %s does not exist", os.Args[1])
        case s3.ErrCodeNoSuchKey:
            exitErrorf("object with key %s does not exist in bucket %s", os.Args[2], os.Args[1])
        }
    }