Architecture

Hosts in the System

In a system deployed by Kayobe we define a number of classes of hosts.

Control host
The control host is the host on which kayobe, kolla and kolla-ansible will be installed, and is typically where the cloud will be managed from.
Seed host
The seed host runs the bifrost deploy container and is used to provision the cloud hosts. Typically the seed host is deployed as a VM but this is not mandatory.
Cloud hosts
The cloud hosts run the OpenStack control plane, network, monitoring, storage, and virtualised compute services. Typically the cloud hosts run on bare metal but this is not mandatory.
Bare metal compute hosts
In a cloud providing bare metal compute services to tenants via ironic, these hosts will run the bare metal tenant workloads. In a cloud with only virtualised compute this category of hosts does not exist.

Note

In many cases the control and seed host will be the same, although this is not mandatory.

Cloud Hosts

Cloud hosts can further be divided into subclasses.

Controllers
Controller hosts run the OpenStack control plane services.
Network
Network hosts run the neutron networking services and load balancers for the OpenStack API services.
Monitoring
Monitoring host run the control plane and workload monitoring services. Currently, kayobe does not deploy any services onto monitoring hosts.

Networks

Kayobe’s network configuration is very flexible but does define a few default classes of networks. These are logical networks and may map to one or more physical networks in the system.

Overcloud out-of-band network
Name of the network used by the seed to access the out-of-band management controllers of the bare metal overcloud hosts.
Overcloud provisioning network
The overcloud provisioning network is used by the seed host to provision the cloud hosts.
Workload out-of-band network
Name of the network used by the overcloud hosts to access the out-of-band management controllers of the bare metal workload hosts.
Workload provisioning network
The workload provisioning network is used by the cloud hosts to provision the bare metal compute hosts.
Internal network
The internal network hosts the internal and admin OpenStack API endpoints.
Public network
The public network hosts the public OpenStack API endpoints.
External network
The external network provides external network access for the hosts in the system.