When Neutron intends to run, neutron calls loadbalancer_db.py. while running loadbalancer_db.py, it gets keystone IP address from /etc/contrail/vnc_api_lib.ini. In that time, neutron user does not have appropriate permission to reach /etc/contrail/vnc_api_lib.ini, so 127.0.0.1 is returned as keystone IP address even is IP address is defined correctly.
Therefore, neutron cannot connect to keystone server and fails to run.
sudo -u neutron ls /etc/contrail
ls: cannot open directory /etc/contrail: Permission denied
2014-09-08 15:57:33.185 ERROR [neutron.service] Error occurred: trying old api-paste.ini.
2014-09-08 15:57:33.191 ERROR [neutron.common.legacy] Skipping unknown group key: firewall_driver
2014-09-08 15:57:33.199 ERROR [neutron.common.config] Unable to load quantum from configuration file /etc/neutron/api-paste.ini.
2014-09-08 15:57:33.200 ERROR [neutron.service] Unrecoverable error: please check log for details.
2014-09-08 15:57:33.610 ERROR [neutron.common.legacy] Skipping unknown group key: firewall_driver
2014-09-08 15:57:33.687 ERROR [neutron.common.legacy] Skipping unknown group key: firewall_driver
