Fail to create a stack calling Fn::GetAtt on Quantum resource

[Simon Pasquier]

I have a template creating a Quantum port and an instance using that port. If I want to access a property of the Quantum port (such as the MAC address of the port) in the UserData of the instance, the stack creation fails .
As a side note, it is not possible today to get the private IP address because Fn::GetAtt(port, 'fixed_ips') returns a list of map.

$ heat stack-create -f CrossReferencing_Quantum_Port.template -P "KeyName=test;NetworkUuid=c45cad0c-415b-4225-b2cb-d6baa0145259" test3
400 Bad Request

The server could not comply with the request since it is either malformed or otherwise incorrect.

 Remote error: StackValidationFailed 404 Not Found The resource could not be found. [u'Traceback (most recent call last):\n', u' File "/opt/stack/heat/heat/openstack/common/rpc/amqp.py", line 276, in _process_data\n rval = self.proxy.dispatch(ctxt, version, method, **args)\n', u' File "/opt/stack/heat/heat/openstack/common/rpc/dispatcher.py", line 133, in dispatch\n return getattr(proxyobj, method)(ctxt, **kwargs)\n', u' File "/opt/stack/heat/heat/engine/service.py", line 50, in wrapped\n return func(self, ctx, *args, **kwargs)\n', u' File "/opt/stack/heat/heat/engine/service.py", line 220, in create_stack\n stack.validate()\n', u' File "/opt/stack/heat/heat/engine/parser.py", line 251, in validate\n raise StackValidationFailed(message=str(ex))\n', u'StackValidationFailed: 404 Not Found\n\nThe resource could not be found.\n\n \n'].

Here is a template to reproduce the bug:
{
  "AWSTemplateFormatVersion" : "2010-09-09",

  "Description" : "Test Quantum resources with very simple image",

  "Parameters" : {

    "KeyName" : {
      "Description" : "Name of an existing EC2 KeyPair to enable SSH access to the instances",
      "Type" : "String"
    },

    "NetworkUuid" : {
      "Description" : "Network UUID",
      "Type" : "String"
    },

    "InstanceType" : {
      "Description" : "WebServer EC2 instance type",
      "Type" : "String",
      "Default" : "m1.nano",
      "AllowedValues" : [ "m1.nano", "t1.micro", "m1.small", "m1.large", "m1.xlarge", "m2.xlarge", "m2.2xlarge", "m2.4xlarge", "c1.medium", "c1.xlarge", "cc1.4xlarge" ],
      "ConstraintDescription" : "must be a valid EC2 instance type."
    }
  },

  "Resources" : {
    "port": {
      "Type": "OS::Quantum::Port",
      "Properties": {
        "network_id": { "Ref": "NetworkUuid" }
      }
    },

    "WebServerSecurityGroup" : {
      "Type" : "AWS::EC2::SecurityGroup",
      "Properties" : {
        "GroupDescription" : "Enable HTTP access via port 80 plus SSH access",
        "SecurityGroupIngress" : [
          {"IpProtocol" : "icmp", "FromPort" : "-1", "ToPort" : "-1", "CidrIp" : "0.0.0.0/0"},
          {"IpProtocol" : "tcp", "FromPort" : "80", "ToPort" : "80", "CidrIp" : "0.0.0.0/0"},
          {"IpProtocol" : "tcp", "FromPort" : "22", "ToPort" : "22", "CidrIp" : "0.0.0.0/0"}
        ]
      }
    },

    "WebServer": {
      "Type": "AWS::EC2::Instance",
      "DependsOn" : "port",
      "Properties": {
        "ImageId" : "cirros-0.3.1-x86_64-uec",
        "InstanceType" : { "Ref" : "InstanceType" },
        "KeyName" : { "Ref" : "KeyName" },
        "SecurityGroups" : [ {"Ref" : "WebServerSecurityGroup"} ],
        "NetworkInterfaces" : [ { "NetworkInterfaceId" : { "Ref" : "port" }, "DeviceIndex" : 0 }],
        "UserData" : { "Fn::Base64" : { "Fn::Join" : ["", [
          "#!/bin/bash -v\n",
          "echo \"Running userdata script at $(date)\" > /tmp/status\n",
          "echo ", { "Fn::GetAtt" : [ "port", "mac_address" ] }, "\n"
        ]]}}
      }
    }
  },

  "Outputs" : {
    "IP" : {
     "Value" : { "Fn::GetAtt" : [ "port", "mac_address" ] },
     "Description" : "IP"
    }
  }
}

heat-engine logs:
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser Traceback (most recent call last):
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/heat/heat/engine/parser.py", line 248, in validate
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser result = res.validate()
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/heat/heat/engine/resources/instance.py", line 388, in validate
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser res = super(Instance, self).validate()
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/heat/heat/engine/resource.py", line 404, in validate
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser return self.properties.validate()
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/heat/heat/engine/properties.py", line 179, in validate
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser self[key]
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/heat/heat/engine/properties.py", line 201, in __getitem__
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser value = self.resolve(self.data[key])
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/heat/heat/engine/parser.py", line 575, in resolve_runtime_data
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser return resolve_runtime_data(self.t, self.resources, snippet)
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/heat/heat/engine/parser.py", line 605, in resolve_runtime_data
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser template.resolve_base64])
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/heat/heat/engine/parser.py", line 614, in transform
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser data = t(data)
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/heat/heat/engine/template.py", line 153, in resolve_attributes
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser return _resolve(lambda k, v: k == 'Fn::GetAtt', handle_getatt, s)
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/heat/heat/engine/template.py", line 244, in _resolve
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser return dict((k, recurse(v)) for k, v in snippet.items())
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/heat/heat/engine/template.py", line 244, in <genexpr>
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser return dict((k, recurse(v)) for k, v in snippet.items())
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/heat/heat/engine/template.py", line 237, in <lambda>
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser recurse = lambda s: _resolve(match, handle, s)
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/heat/heat/engine/template.py", line 244, in _resolve
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser return dict((k, recurse(v)) for k, v in snippet.items())
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/heat/heat/engine/template.py", line 244, in <genexpr>
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser return dict((k, recurse(v)) for k, v in snippet.items())
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/heat/heat/engine/template.py", line 237, in <lambda>
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser recurse = lambda s: _resolve(match, handle, s)
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/heat/heat/engine/template.py", line 246, in _resolve
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser return [recurse(v) for v in snippet]
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/heat/heat/engine/template.py", line 237, in <lambda>
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser recurse = lambda s: _resolve(match, handle, s)
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/heat/heat/engine/template.py", line 246, in _resolve
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser return [recurse(v) for v in snippet]
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/heat/heat/engine/template.py", line 237, in <lambda>
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser recurse = lambda s: _resolve(match, handle, s)
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/heat/heat/engine/template.py", line 243, in _resolve
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser return handle(recurse(v))
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/heat/heat/engine/template.py", line 148, in handle_getatt
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser return resources[resource].FnGetAtt(att)
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/heat/heat/engine/resources/quantum/port.py", line 65, in FnGetAtt
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser self.resource_id)['port']
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/python-quantumclient/quantumclient/v2_0/client.py", line 108, in with_params
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser ret = self.function(instance, *args, **kwargs)
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/python-quantumclient/quantumclient/v2_0/client.py", line 264, in show_port
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser return self.get(self.port_path % (port), params=_params)
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/python-quantumclient/quantumclient/v2_0/client.py", line 988, in get
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser headers=headers, params=params)
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/python-quantumclient/quantumclient/v2_0/client.py", line 973, in retry_request
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser headers=headers, params=params)
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/python-quantumclient/quantumclient/v2_0/client.py", line 915, in do_request
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser self._handle_fault_response(status_code, replybody)
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/python-quantumclient/quantumclient/v2_0/client.py", line 895, in _handle_fault_response
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser exception_handler_v20(status_code, des_error_body)
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser File "/opt/stack/python-quantumclient/quantumclient/v2_0/client.py", line 88, in exception_handler_v20
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser message=message)
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser QuantumClientException: 404 Not Found
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser
2013-05-15 10:48:50.263 24245 TRACE heat.engine.parser The resource could not be found.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/29317

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/29317
Committed: http://github.com/openstack/heat/commit/1796f3ec0f2787738d83b62a66b5efaa8563146d
Submitter: Jenkins
Branch: master

commit 1796f3ec0f2787738d83b62a66b5efaa8563146d
Author: Steve Baker <email address hidden>
Date: Thu May 16 10:02:34 2013 +1200

    Tolerate resource lookup errors for quantum FnGetAtt.

    Fixes bug #1180293

    Change-Id: I5384456bbbf53558036573c983be0b65e8883612

[Steve Baker (steve-stevebaker)]

Please retest with the above commit and report back

[Simon Pasquier (simon-pasquier)]

It doesn't work with my original description because Fn::GetAtt returns None and it now fails on Fn::Join. Not sure if converting none object to empty string is the right approach though?

BTW it might be not be a bad idea to check in resolve_join() that all elements of the list are strings and raise an exception if not (right now the error message is not super obvious).