openstack-ansible/doc/source/user/prod/provnet_groups.rst

Provider network groups

Many network configuration examples assume a homogenous environment, where each server is configured identically and consistent network interfaces and interface names can be assumed across all hosts.

Recent changes to OSA enables deployers to define provider networks that apply to particular inventory groups and allows for a heterogeneous network configuration within a cloud environment. New groups can be created or existing inventory groups, such as network_hosts or compute_hosts, can be used to ensure certain configurations are applied only to hosts that meet the given parameters.

Before reading this document, please review the following scenario:

• :dev_docs:Production environment <user/prod/example.html>

This example environment has the following characteristics:

• A network_hosts group consisting of three collapsed infrastructure/network (control plane) hosts
• A compute_hosts group consisting of two compute hosts
• Multiple Network Interface Cards (NIC) used as provider network interfaces that vary between hosts

Note

The groups network_hosts and compute_hosts are pre-defined groups in an OpenStack-Ansible deployment.

The following diagram demonstates servers with different network interface names:

In this example environment, infrastructure/network nodes hosting L2/L3/DHCP agents will utilize an interface named ens1f0 for the provider network physnet1. Compute nodes, on the other hand, will utilize an interface named ens2f0 for the same physnet1 provider network.

Note

Differences in network interface names may be the result of a difference in drivers and/or PCI slot locations.

Deployment configuration

Environment layout

The /etc/openstack_deploy/openstack_user_config.yml file defines the environment layout.

The following configuration describes the layout for this environment.

../../../../etc/openstack_deploy/openstack_user_config.yml.provnet-group.example

Hosts in the network_hosts group will map physnet1 to the ens1f0 interface, while hosts in the compute_hosts group will map physnet1 to the ens2f0 interface. Additional provider mappings can be established using the same format in a separate definition.

An additional provider interface definition named physnet2 using different interfaces between hosts may resemble the following:

- network:
    container_bridge: "br-vlan2"
    container_type: "veth"
    container_interface: "eth13"
    host_bind_override: "ens1f1"
    type: "vlan"
    range: "2000:2999"
    net_name: "physnet2"
    group_binds:
      - network_hosts
- network:
    container_bridge: "br-vlan2"
    container_type: "veth"
    host_bind_override: "ens2f1"
    type: "vlan"
    range: "2000:2999"
    net_name: "physnet2"
    group_binds:
      - compute_hosts

Note

The container_interface parameter is only necessary when Neutron agents are run in containers, and can be excluded in many cases. The container_bridge and container_type parameters also relate to infrastructure containers, but should remain defined for legacy purposes.

Custom Groups

Custom inventory groups can be created to assist in segmenting hosts beyond the built-in groups provided by OpenStack-Ansible.

Before creating custom groups, please review the following:

• :dev_docs:Configuring the inventory <reference/inventory/configure-inventory.html>

The following diagram demonstates how a custom group can be used to further segment hosts:

When creating a custom group, first create a skeleton in /etc/openstack_deploy/env.d/. The following is an example of an inventory skeleton for a group named custom2_hosts that will consist of bare metal hosts, and has been created at /etc/openstack_deploy/env.d/custom2_hosts.yml.

---
physical_skel:
  custom2_containers:
    belongs_to:
      - all_containers
  custom2_hosts:
    belongs_to:
      - hosts

Define the group and its members in a corresponding file in /etc/openstack_deploy/conf.d/. The following is an example of a group named custom2_hosts defined in /etc/openstack_deploy/conf.d/custom2_hosts.yml consisting of a single member, compute2:

---
# custom example
custom2_hosts:
  compute2:
    ip: 172.29.236.17

The custom group can then be specifed when creating a provider network, as shown here:

- network:
    container_bridge: "br-vlan"
    container_type: "veth"
    host_bind_override: "ens8f1"
    type: "vlan"
    range: "101:200,301:400"
    net_name: "physnet1"
    group_binds:
      - custom2_hosts