iot client register_certificate missing resourceArn and resourceId in ResourceAlreadyExistsException

I’m working on a registration script. When I register a certificate, which is already registered I get back ResourceAlreadyExistsException.

import boto3
import botocore
from collections import namedtuple

#debug
boto3.set_stream_logger(name='botocore')

CAResponse = namedtuple("CAResponse", "certId arn")

client = boto3.client('iot')
try:
    with open("device_pem", 'r') as device_pem_file, open("rootCA.pem", 'r') as root_pem_file:
        device_pem_string = device_pem_file.read()
        root_pem_string = root_pem_file.read()
        try:
            response = self.client.register_certificate(
                certificatePem=device_pem_string,
                caCertificatePem=root_pem_string
            )
            if "certificateId" in response and "certificateArn" in response:
                return CAResponse(certId=response["certificateId"], arn=response["certificateArn"])

        except botocore.exceptions.ClientError as e:
            print "%s register errror %r " % (e, e.response)
            raise e

except IOError as e:
    raise e

The exception is a botocore.errorfactory.ResourceAlreadyExistsException which I can’t seem to find the BotoCore source. When I cast it as a botocore.exceptions.ClientError I only get a Message & Code in the error.response.

With the logger running I can see that AWS gives the following response:

2017-02-13 17:03:52,634 botocore.parsers [DEBUG] Response body:
{
"message":"The certificate is already provisioned or registered",
"resourceArn":"target_arn",
"resourceId":"target_id"
}

Is there any way to retrieve this response body, or parse it out of the exception? As I see it there’s no function to retrieve the resourceArn & rescueId only by going through all of them wich will be a hassle when working with thousands of devices.

[apregoe]

Hi! you have to catch it from the client itself. eg from a cloudwatch logs client:

    cw_client = boto3.client('logs')
    try:
        cw_client.create_log_stream(
            logGroupName='someloggroup',
            logStreamName='somestream'
        )
    except cw_client.exceptions.ResourceAlreadyExistsException as e:
        print('Log Stream already created. Continuing to publishing the log')

[mscheper]

It seems this exception class gets created on the fly, so I don’t think it’s possible to import it. Has anybody found a way to catch it? I can import and catch botocore.errorfactory.BaseClientExceptions; is there a function to test whether it’s a ResourceAlreadyExistsException?