Horizon service

Horizon is the default dashboard / UI for Openstack

https://docs.openstack.org/horizon/2025.1/install/install-ubuntu.html

Install and configure package

sudo apt install openstack-dashboard

/etc/openstack-dashboard/local_settings.py

OPENSTACK_HOST = "<SERVERNAME>"
OPENSTACK_KEYSTONE_URL = "http://%s:5000/identity/v3" % OPENSTACK_HOST #Add port
OPENSTACK_KEYSTONE_MULTIDOMAIN_SUPPORT = True
OPENSTACK_API_VERSIONS = {
    "identity": 3,
    "image": 2,
    "volume": 3,
}
OPENSTACK_KEYSTONE_DEFAULT_DOMAIN = "Default"
OPENSTACK_NEUTRON_NETWORK = {
    ...
    'enable_router': False,
    'enable_quotas': False,
    'enable_ipv6': False,
    'enable_distributed_router': False,
    'enable_ha_router': False,
    'enable_fip_topology_check': False,
}

ALLOWED_HOSTS = ['<FQDN1>', '<FQDN1>'] #Note that Allowed hosts might be present in the Ubuntu section, do not change this
SESSION_ENGINE = 'django.contrib.sessions.backends.cache'

CACHES = {
    'default': {
         'BACKEND': 'django.core.cache.backends.memcached.PyMemcacheCache',
         'LOCATION': 'controller:11211',
    }
}

Verify the following in /etc/apache2/conf-available/openstack-dashboard.conf

WSGIApplicationGroup %{GLOBAL}

Reload apache

sudo systemctl reload apache2.service

Verify

Go to the http://FQDN/horizon and check if the login appears

In my case it did not

What I've found in two different installs this has been because of missing or invalid template and/or static cache. To rebuild it

sudo rm -rf /var/lib/openstack-dashboard/* 
sudo rm -rf /var/lib/horizon/* 
sudo python3 /usr/share/openstack-dashboard/manage.py collectstatic --noinput
sudo python3 /usr/share/openstack-dashboard/manage.py compress
sudo systemctl restart apache2

We might also need to reset the owner of the files in openstack-dashboard

sudo chown -R horizon:horizon /var/lib/openstack-dashboard/

Now the dashboard should load