I have tried to reinstall packstack keystone but failed with openstack keystone errors, unable to start openstack-keystone manually.

tried to install juno version.

192.168.1.66_keystone.pp:                       [ ERROR ]
Applying Puppet manifests                         [ ERROR ]

ERROR : Error appeared during Puppet run: 192.168.1.66_keystone.pp
Error: Could not start Service[keystone]: Execution of '/usr/bin/systemctl start openstack-keystone' returned 1: Job for openstack-keystone.service failed. See 'systemctl status openstack-keystone.service' and 'journalctl -xn' for details.
You will find full trace in log /var/tmp/packstack/20151013-055930-GwXrn2/manifests/192.168.1.66_keystone.pp.log
Please check log file /var/tmp/packstack/20151013-055930-GwXrn2/openstack-setup.log for more information

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cat /var/log/messages

Oct 13 06:07:53 os-demo systemd: Stopping OpenStack Identity Service (code-named Keystone)...
Oct 13 06:07:53 os-demo systemd: Starting OpenStack Identity Service (code-named Keystone)...
Oct 13 06:07:54 os-demo keystone-all: 2015-10-13 06:07:54.366 29956 CRITICAL keystone [-] ConfigFileNotFound: An unexpected error prevented the server from fulfilling your request.
Oct 13 06:07:54 os-demo keystone-all: 2015-10-13 06:07:54.366 29956 TRACE keystone Traceback (most recent call last):
Oct 13 06:07:54 os-demo keystone-all: 2015-10-13 06:07:54.366 29956 TRACE keystone   File "/usr/bin/keystone-all", line 134, in <module>
Oct 13 06:07:54 os-demo keystone-all: 2015-10-13 06:07:54.366 29956 TRACE keystone     paste_config = config.find_paste_config()
Oct 13 06:07:54 os-demo keystone-all: 2015-10-13 06:07:54.366 29956 TRACE keystone   File "/usr/lib/python2.7/site-packages/keystone/config.py", line 90, in find_paste_config
Oct 13 06:07:54 os-demo keystone-all: 2015-10-13 06:07:54.366 29956 TRACE keystone     raise exception.ConfigFileNotFound(config_file=paste_config_value)
Oct 13 06:07:54 os-demo keystone-all: 2015-10-13 06:07:54.366 29956 TRACE keystone ConfigFileNotFound: An unexpected error prevented the server from fulfilling your request.
Oct 13 06:07:54 os-demo keystone-all: 2015-10-13 06:07:54.366 29956 TRACE keystone
Oct 13 06:07:54 os-demo systemd: openstack-keystone.service: main process exited, code=exited, status=1/FAILURE
Oct 13 06:07:54 os-demo systemd: Failed to start OpenStack Identity Service (code-named Keystone).
Oct 13 06:07:54 os-demo systemd: Unit openstack-keystone.service entered failed state.
Oct 13 06:07:54 os-demo systemd: openstack-keystone.service holdoff time over, scheduling restart.
Oct 13 06:07:54 os-demo systemd: Stopping OpenStack Identity Service (code-named Keystone)...
Oct 13 06:07:54 os-demo systemd: Starting OpenStack Identity Service (code-named Keystone)...
Oct 13 06:07:54 os-demo keystone-all: 2015-10-13 06:07:54.911 29966 CRITICAL keystone [-] ConfigFileNotFound: An unexpected error prevented the server from fulfilling your request.
Oct 13 06:07:54 os-demo keystone-all: 2015-10-13 06:07:54.911 29966 TRACE keystone Traceback (most recent call last):
Oct 13 06:07:54 os-demo keystone-all: 2015-10-13 06:07:54.911 29966 TRACE keystone   File "/usr/bin/keystone-all", line 134, in <module>
Oct 13 06:07:54 os-demo keystone-all: 2015-10-13 06:07:54.911 29966 TRACE keystone     paste_config = config.find_paste_config()
Oct 13 06:07:54 os-demo keystone-all: 2015-10-13 06:07:54.911 29966 TRACE keystone   File "/usr ...