ceilometer: The request you have made requires authentication. (HTTP 401) about coa HOT 2 CLOSED

Disappeared when by solving:

• #43 Request returned failure status. Invalid OpenStack Identity credentials
• #45 Error communicating with http://controller:8777 [Errno 111] Connection refused

from coa.

Ceilometer service inspection gives the following:

systemctl | grep ceilometer

● openstack-ceilometer-api.service loaded failed failed OpenStack ceilometer API service
openstack-ceilometer-central.service loaded active running OpenStack ceilometer central agent
openstack-ceilometer-collector.service loaded active running OpenStack ceilometer collection service
openstack-ceilometer-compute.service loaded active running OpenStack ceilometer compute agent
openstack-ceilometer-notification.service loaded active running OpenStack ceilometer notification agent

enabled and started openstack-ceilometer-api.service :

systemctl enable openstack-ceilometer-api.service

Created symlink from /etc/systemd/system/multi-user.target.wants/openstack-ceilometer-api.service to /usr/lib/systemd/system/openstack-ceilometer-api.service.

systemctl start openstack-ceilometer-api.service

systemctl | grep openstack-ceilometer-api.service

openstack-ceilometer-api.service loaded active running OpenStack ceilometer API service

Still the same error:
ceilometer meter-list

The request you have made requires authentication. (HTTP 401) (Request-ID: req-84fef3b0-fedd-40dc-ac8c-4e6620629bc2)

from coa.