[barbican][OC4.0] lbaas creation fails for non-admin user in non-default domain

[Inessa Vasilevskaya]

Env: OS pike, opencontrail 4.0, barbican, keystone domain.

Steps to reproduce:

- Create some users in keystone domain.
- Follow instructions on lbaas creation [1]

Follow the steps from the link below with following difference.
https://wiki.openstack.org/wiki/Network/LBaaS/docs/how-to-create-tls-loadbalancer
1 Make sure you are using user from non-default domain with member and creator role to upload secret with ssl certificate.
2 Make sure when you create lbaas VIP you are doing this in non-default domain project and user is also not;

Expected result:
VIP with https is created and ssl certificate is installed.
Actual result:
lbaas is not able to download secret created by user in any project other than the project where opencontrail_barbican_user has admin privileges.

/var/log/contrail/contrail-lbaas-haproxy-stdout.log from compute

08/13/2018 20:31:31 ERROR Exception in Createing haproxy config for Loadbalancer-ID ee51ff08-8205-4c45-9261-8e12b4a5a3cf
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/opencontrail_vrouter_netns/haproxy_process.py", line 189, in start_update_haproxy
    haproxy_cfg_file = get_haproxy_config_file(cfg_file, dir_name)
  File "/usr/lib/python2.7/dist-packages/opencontrail_vrouter_netns/haproxy_process.py", line 91, in get_haproxy_config_file
    provider, haproxy_config, lbaas_auth_conf, dir_name)
  File "/usr/lib/python2.7/dist-packages/opencontrail_vrouter_netns/cert_mgr/cert_manager.py", line 25, in update_ssl_config
    update_ssl_config(haproxy_config, dest_dir)
  File "/usr/lib/python2.7/dist-packages/opencontrail_vrouter_netns/cert_mgr/barbican_cert_manager.py", line 129, in update_ssl_config
    pem_file_name = tls.create_pem_file(dest_dir)
  File "/usr/lib/python2.7/dist-packages/opencontrail_vrouter_netns/cert_mgr/tls.py", line 41, in create_pem_file
    pem_file_name = dest_dir + '/'+ self.primary_cn + '.pem'
TypeError: cannot concatenate 'str' and 'NoneType' objects
08/13/2018 20:31:31 ERROR <type 'exceptions.TypeError'>
08/13/2018 20:31:31 ERROR Inappropriate argument type.
08/13/2018 20:31:31 ERROR cannot concatenate 'str' and 'NoneType' objects
08/13/2018 20:31:31 MSG Stopping haproxy for Loadbalancer-ID

From what I see in the code it is a by design behavior as all resources are accessed as contrail admin https://github.com/Juniper/contrail-controller/blob/master/src/vnsw/opencontrail-vrouter-netns/opencontrail_vrouter_netns/cert_mgr/barbican_cert_manager.py#L28

[Pavlo Shchelokovskyy (pshchelo)]

looking at the code, the same bug should affect OpenContrail 3.x as well