Description of problem:
Cloudforms's fog-openstack ruby gem randomly selects a tenant when allocating a floating IP instead of using the tenant specified during connection setup.

Version-Release number of selected component (if applicable):
CFME 5.6.1.2.20160810181333_8ba817b
fog-core (1.42.0)
fog-google (0.3.2)
fog-json (1.0.2)
fog-openstack (0.1.11)
fog-xml (0.1.2)


How reproducible:
100%


Steps to Reproduce:
1. Create two OpenStack tenants 
2. In each tenant, create an instance WITHOUT assigning a floating ip
3. On the cloudforms appliance, run the script attached below to create a floating IP and allocate it to the instance, once for each tenant&instance

Actual results:
While one invocation will succeed, the other invocation will fail with a log output such as:

[root@cloudforms ~]# ./test2.rb http://192.168.101.81:5000/v3/auth/tokens 59fef26e2edb49a381560f53651a494e admin xxxxx demo-infra e66f50e2-4fc4-4b8e-8058-25f7eb264d60
I, [2016-11-15T22:02:07.139591 #44641]  INFO -- : Allocated   <Fog::Compute::OpenStack::Address
    id="33ef8841-404b-4070-ab70-e8a713da72a2",
    ip="10.32.105.136",
    pool="guests",
    fixed_ip=nil,
    instance_id=nil
  >
/opt/rh/cfme-gemset/gems/excon-0.51.0/lib/excon/middlewares/expects.rb:6:in `response_call': Expected([200, 202]) <=> Actual(400 Bad Request) (Excon::Error::BadRequest)
excon.error.response
  :body          => "{\"badRequest\": {\"message\": \"Unable to associate floating IP 10.32.105.136 to fixed IP 172.20.0.7 for instance e66f50e2-4fc4-4b8e-8058-25f7eb264d60. Error: Bad floatingip request: Port 81c66147-9015-4872-a561-3ebbd818e73e is associated with a different tenant than Floating IP 33ef8841-404b-4070-ab70-e8a713da72a2 and therefore cannot be bound..\\nNeutron server returns request_ids: ['req-d8741196-38f5-4826-80e0-eace85e43ce5']\", \"code\": 400}}"
  :cookies       => [
  ]
  :headers       => {
    "Content-Length"               => "442"
    "Content-Type"                 => "application/json; charset=UTF-8"
    "Date"                         => "Tue, 15 Nov 2016 21:02:09 GMT"
    "Vary"                         => "X-OpenStack-Nova-API-Version"
    "X-Compute-Request-Id"         => "req-af949c79-84fc-470b-a80d-23e6b4b8f5e9"
    "X-Openstack-Nova-Api-Version" => "2.1"
  }
  :host          => "192.168.101.81"
  :local_address => "192.168.101.17"
  :local_port    => 47740
  :path          => "/v2.1/a9374b0dde9c4b14b0b4661cb3402e27/servers/e66f50e2-4fc4-4b8e-8058-25f7eb264d60/action.json"
  :port          => 8774
  :reason_phrase => "Bad Request"
  :remote_ip     => "192.168.101.81"
  :status        => 400
  :status_line   => "HTTP/1.1 400 Bad Request\r\n"
	from /opt/rh/cfme-gemset/gems/excon-0.51.0/lib/excon/middlewares/response_parser.rb:8:in `response_call'
	from /opt/rh/cfme-gemset/gems/excon-0.51.0/lib/excon/connection.rb:389:in `response'
	from /opt/rh/cfme-gemset/gems/excon-0.51.0/lib/excon/connection.rb:253:in `request'
	from /opt/rh/cfme-gemset/gems/fog-core-1.42.0/lib/fog/core/connection.rb:81:in `request'
	from /opt/rh/cfme-gemset/gems/fog-openstack-0.1.11/lib/fog/openstack/core.rb:81:in `request'
	from /opt/rh/cfme-gemset/gems/fog-openstack-0.1.11/lib/fog/compute/openstack/requests/server_action.rb:6:in `server_action'
	from /opt/rh/cfme-gemset/gems/fog-openstack-0.1.11/lib/fog/compute/openstack/requests/associate_address.rb:7:in `associate_address'
	from ./test2.rb:31:in `<main>'
[root@cloudforms ~]#


Expected results:
Both invocations should succeed with a log output such as:
[root@cloudforms ~]# ./test2.rb http://192.168.101.81:5000/v3/auth/tokens 59fef26e2edb49a381560f53651a494e admin xxxx demo-vms     9061d5f7-71db-4254-8e84-587ff0cdac13
I, [2016-11-15T22:17:46.146016 #45792]  INFO -- : Allocated   <Fog::Compute::OpenStack::Address
    id="09569946-6c41-4294-8477-da3ffd8fed0d",
    ip="10.32.105.137",
    pool="guests",
    fixed_ip=nil,
    instance_id=nil
  >
I, [2016-11-15T22:17:47.125436 #45792]  INFO -- : Associate: Response: #<Excon::Response:0x00000001b184c8 @data={:body=>"", :cookies=>[], :host=>"192.168.101.81", :headers=>{"Content-Type"=>"text/html; charset=UTF-8", "Content-Length"=>"0", "X-Openstack-Nova-Api-Version"=>"2.1", "Vary"=>"X-OpenStack-Nova-API-Version", "X-Compute-Request-Id"=>"req-c14c7c38-e899-4260-9b5a-181536b1e3b8", "Date"=>"Tue, 15 Nov 2016 21:17:49 GMT"}, :path=>"/v2.1/a9374b0dde9c4b14b0b4661cb3402e27/servers/9061d5f7-71db-4254-8e84-587ff0cdac13/action.json", :port=>8774, :status=>202, :status_line=>"HTTP/1.1 202 Accepted\r\n", :reason_phrase=>"Accepted", :remote_ip=>"192.168.101.81", :local_port=>50964, :local_address=>"192.168.101.17"}, @body="", @headers={"Content-Type"=>"text/html; charset=UTF-8", "Content-Length"=>"0", "X-Openstack-Nova-Api-Version"=>"2.1", "Vary"=>"X-OpenStack-Nova-API-Version", "X-Compute-Request-Id"=>"req-c14c7c38-e899-4260-9b5a-181536b1e3b8", "Date"=>"Tue, 15 Nov 2016 21:17:49 GMT"}, @status=202, @remote_ip="192.168.101.81", @local_port=50964, @local_address="192.168.101.17">


Additional info:

When tracing the network traffic via Wireshark you can see that the interaction works as follows:
1) Fog authenticates the user using username+pw and receives a token and user ID (POST /v3/auth/tokens)

2) Fog retrieves the list of tenants available to the user (GET /v3/users/a12b9e2ec11b7fee4f21d0f3b3a4c643c531fa8d0625311b04af0228c833adf0/projects)

3) Fog requests a token for the FIRST project retrieved in step 2 (instead of the tenant/project supplied during connection creation): POST /v3/auth/tokens HTTP/1.1
User-Agent: fog-core/1.42.0
Content-Type: application/json
Host: 192.168.101.81:5000
Content-Length: 155

{"auth":{"identity":{"methods":["token"],"token":{"id":"bd63498f437149909ce69a3640c61446"}},"scope":{"project":{"id":"44322c412882479f86fcf45b4d5b8193"}}}}


--- BEGIN TEST SCRIPT ---
#!/usr/bin/env ruby
require 'rubygems'
require 'fog/openstack'
require 'logger'

auth_url = ARGV[0]
domain = ARGV[1]
username = ARGV[2]
password = ARGV[3]
tenant = ARGV[4]
instance_uuid = ARGV[5]

logger = Logger.new(STDOUT)
logger.level = Logger::INFO

credentials={
  :provider => "OpenStack",
  :openstack_auth_url => auth_url,
  :openstack_domain_id => domain,
  :openstack_username => username,
  :openstack_api_key => password,
  :openstack_tenant => tenant
}

conn = Fog::Compute.new(credentials)
#address = conn.allocate_address("guests").body
#logger.info("Allocated #{address['floating_ip'].inspect}")
#res = conn.associate_address(instance_uuid, "#{address['floating_ip']['ip']}")
address = conn.addresses.create pool: "guests"
logger.info("Allocated #{address.inspect}")
res = conn.associate_address(instance_uuid, "#{address.ip}")
logger.info("Associate: Response: #{res.inspect}")
--- END TEST SCRIPT ---