Custom SSL CA
Some OpenStack deployments may use a custom SSL CA file. If so, this must be provided to the charm via the ssl_ca config option, for example (if vault is supplying the CA for the deployment):
juju exec -u vault/leader 'leader-get root-ca' > ca.crt
juju config openstack-exporter ssl_ca="$(cat ca.crt)"
This config value may be changed by the user at any time. The openstack-exporter service will be restarted to pick up the changed SSL CA.