Hi, I am trying to create instance using heat template and python-API, but it is giving me an error stating as below " heatclient.exc.HTTPBadRequest: ERROR: <errorresponse><error><message>The request signature does not conform to AWS standards</message>IncompleteSignature<type>Sender</type></error></errorresponse>"

code:

template_file = 'heat.yaml'
template = open(template_file, 'r')
tr = template.read()        
stack = heat.stacks.create(stack_name='stack_new', template=tr,parameters={} )

heat.yaml

heat_template_version: 2015-04-30
description: Simple template to deploy a single compute instance
resources:
  my_instance-new:
    type: OS::Nova::Server
    properties:
      image: c10cc9d9-424f-47b5-b00c-fec94958bf75
      flavor: m1.tiny
      key_name: test_key
      networks:
        - network: ext