Hi,
It seems like when you have an SQS Queue invoking an Lambda function, that it does get the SQS message, however it seems that the MessageAttributes is always an empty object, even though there is MessageAttributes sent a long.


import re
import uuid
import xmltodict
from six.moves.urllib import parse as urlparse
from six.moves.urllib.parse import urlencode
from requests.models import Request, Response
from localstack import config
from localstack.config import HOSTNAME_EXTERNAL, SQS_PORT_EXTERNAL
from localstack.utils.common import to_str, md5
from localstack.utils.analytics import event_publisher
from localstack.services.awslambda import lambda_api
from localstack.services.generic_proxy import ProxyListener
XMLNS_SQS = 'http://queue.amazonaws.com/doc/2012-11-05/'
SUCCESSFUL_SEND_MESSAGE_XML_TEMPLATE = (
    '<?xml version="1.0"?>'  
    '<SendMessageResponse xmlns="' + XMLNS_SQS + '">'  
        '<SendMessageResult>'  
            '<MD5OfMessageAttributes>{message_attr_hash}</MD5OfMessageAttributes>'  
            '<MD5OfMessageBody>{message_body_hash}</MD5OfMessageBody>'  
            '<MessageId>{message_id}</MessageId>'  
        '</SendMessageResult>'