VScaler: Change services config files with kolla

An operator can change the location where custom config files are read from by editing /etc/kolla/globals.yml and adding the following line:

# The directory to merge custom config files the kolla's config files
node_custom_config: "/etc/kolla/config"

Kolla allows the operator to override configuration of services. Kolla will look for a file in /etc/kolla/config/<< service name >>/<< config file >>. This can be done per-project, per-service or per-service-on-specified-host. For example to override scheduler_max_attempts in nova scheduler, the operator needs to create /etc/kolla/config/nova/nova-scheduler.conf with content:

[DEFAULT]
scheduler_max_attempts = 100

Another example I used, is changing the novncproxy_base_url parameter in the nova-compute nodes. I added the /etc/kolla/config/nova/nova-compute.conf file with these contents:

[vnc]
novncproxy_base_url = http://uk2.vscaler.com:6080/vnc_auto.html

After those changes just run the reconfigure command:

kolla-ansible reconfigure -i <path to multinode file>