TripleO – Openstack-on-Openstack:
TripleO also known as Openstack-on-Openstack install openstack using openstack. This is an openstack deployment and management tool. This is a program for installing, updating and managing the openstack environment.
In this program, there are two concepts – Undercloud and Overcloud.
Undercloud : Undercloud is a simple, all-in-one openstack installation running on the physical machine. In the Triple O program, first the undercloud machine will be installed and configured with all-in-one single node openstack installation with minimal basic services like – nova, neutron, heat, ironic, glance, keystone etc. This undercloud machine will be used to install and manage the overcloud machines. This undercloud openstack is not an operational cloud to host the guest virtual machines. This openstack installation will be used to install the actual operational production cloud for hosting the guest virtual machines. There is no HA environment for the undercloud machine.
Overcloud : Overcloud is the actual operational cloud which is installed by the undercloud machine. Undercloud machine uses openstack components like heat, ironic services to install the overcloud servers. Overcloud machines are the physical servers on which the operational openstack cloud will be deployed. Here, we can create the controllers in the HA environment and deploy as many as compute nodes and storage nodes based on the requirement.This will be fully automated installation of openstack by undercloud machine. Undercloud machine uses the HOT (Heat Orchestration Template) templates to automate the overcloud openstack installation and uses ironic service for the PXE boot of the overcloud physical machines.
Redhat Director is one of the good example of the Openstack-on-Openstack installation. In Redhat, Redhat director is the undercloud machine and then this director install the overcloud openstack cloud environment. This is a fully automated way to install and manage the openstack cloud environment in the production. Triple O uses ansible in background to push the several configurations on the different physical machines.