Chapter 8. Basic network isolation

The overcloud assigns services to the provisioning network by default. However, the director can divide overcloud network traffic into isolated networks. To use isolated networks, the overcloud contains an environment file that enables this feature. The environments/network-isolation.j2.yaml file in the director’s core Heat templates is a Jinja2 file that defines all ports and VIPs for each network in your composable network file. When rendered, it results in a network-isolation.yaml file in the same location with the full resource registry. For example:

resource_registry:
  # networks as defined in network_data.yaml
  OS::TripleO::Network::Storage: ../network/storage.yaml
  OS::TripleO::Network::StorageMgmt: ../network/storage_mgmt.yaml
  OS::TripleO::Network::InternalApi: ../network/internal_api.yaml
  OS::TripleO::Network::Tenant: ../network/tenant.yaml
  OS::TripleO::Network::External: ../network/external.yaml

  # Port assignments for the VIPs
  OS::TripleO::Network::Ports::StorageVipPort: ../network/ports/storage.yaml
  OS::TripleO::Network::Ports::StorageMgmtVipPort: ../network/ports/storage_mgmt.yaml
  OS::TripleO::Network::Ports::InternalApiVipPort: ../network/ports/internal_api.yaml
  OS::TripleO::Network::Ports::ExternalVipPort: ../network/ports/external.yaml
  OS::TripleO::Network::Ports::RedisVipPort: ../network/ports/vip.yaml

  # Port assignments by role, edit role definition to assign networks to roles.
  # Port assignments for the Controller
  OS::TripleO::Controller::Ports::StoragePort: ../network/ports/storage.yaml
  OS::TripleO::Controller::Ports::StorageMgmtPort: ../network/ports/storage_mgmt.yaml
  OS::TripleO::Controller::Ports::InternalApiPort: ../network/ports/internal_api.yaml
  OS::TripleO::Controller::Ports::TenantPort: ../network/ports/tenant.yaml
  OS::TripleO::Controller::Ports::ExternalPort: ../network/ports/external.yaml

  # Port assignments for the Compute
  OS::TripleO::Compute::Ports::StoragePort: ../network/ports/storage.yaml
  OS::TripleO::Compute::Ports::InternalApiPort: ../network/ports/internal_api.yaml
  OS::TripleO::Compute::Ports::TenantPort: ../network/ports/tenant.yaml

  # Port assignments for the CephStorage
  OS::TripleO::CephStorage::Ports::StoragePort: ../network/ports/storage.yaml
  OS::TripleO::CephStorage::Ports::StorageMgmtPort: ../network/ports/storage_mgmt.yaml

The first section of this file has the resource registry declaration for the OS::TripleO::Network::* resources. By default, these resources use the OS::Heat::None resource type, which does not create any networks. By redirecting these resources to the YAML files for each network, you enable the creation of these networks.

The next several sections create the IP addresses for the nodes in each role. The controller nodes have IPs on each network. The compute and storage nodes each have IPs on a subset of the networks.

Other functions of overcloud networking, such as Chapter 9, Custom composable networks and Chapter 10, Custom network interface templates rely on this network isolation environment file. As a result, you need to include the name of the rendered file with your deployment commands. For example:

$ openstack overcloud deploy --templates \
    ...
    -e /usr/share/openstack-tripleo-heat-templates/environments/network-isolation.yaml \
    ...

The network_data file provides a method to configure the default isolated networks. This procedure shows how to create a custom network_data file and configure it according to your network requirements.

Edit the following for each network:

Include the custom network_data file with your deployment using the -n option. Without the -n option, the deployment command uses the default network details.

The overcloud network configuration requires a set of the network interface templates. These templates are standard Heat templates in YAML format. Each role requires a NIC template so the director can configure each node within that role correctly.

All NIC templates contain the same sections as standard Heat templates:

The default NIC templates in /usr/share/openstack-tripleo-heat-templates/network/config take advantage of Jinja2 syntax to help render the template. For example, the following snippet from the single-nic-vlans configuration renders a set of VLANs for each network:

{%- for network in networks if network.enabled|default(true) and network.name in role.networks %}
- type: vlan
  vlan_id:
    get_param: {{network.name}}NetworkVlanID
  addresses:
  - ip_netmask:
      get_param: {{network.name}}IpSubnet
{%- if network.name in role.default_route_networks %}

For default Compute nodes, this only renders network information for the Storage, Internal API, and Tenant networks:

- type: vlan
  vlan_id:
    get_param: StorageNetworkVlanID
  device: bridge_name
  addresses:
  - ip_netmask:
      get_param: StorageIpSubnet
- type: vlan
  vlan_id:
    get_param: InternalApiNetworkVlanID
  device: bridge_name
  addresses:
  - ip_netmask:
      get_param: InternalApiIpSubnet
- type: vlan
  vlan_id:
    get_param: TenantNetworkVlanID
  device: bridge_name
  addresses:
  - ip_netmask:
      get_param: TenantIpSubnet

Chapter 10, Custom network interface templates explores how to render the default Jinja2-based templates to standard YAML versions, which you can use as a basis for customization.

The director contains templates in /usr/share/openstack-tripleo-heat-templates/network/config/ to suit most common network scenarios. The following table outlines each NIC template set and the respective environment file to use to enable the templates.

Each default NIC template set contains a role.role.j2.yaml template. This file uses Jinja2 to render additional files for each composable role. For example, if your overcloud uses Compute, Controller, and Ceph Storage roles, the deployment renders new templates based on role.role.j2.yaml, such as the following templates:

This procedure shows you how to enable basic network isolation using one of the default NIC templates. In this case, it is the single NIC with VLANs template (single-nic-vlans).

For example:

$ openstack overcloud deploy --templates \
    ...
    -n /home/stack/network_data.yaml \
    -e /usr/share/openstack-tripleo-heat-templates/environments/network-isolation.yaml \
    -e /usr/share/openstack-tripleo-heat-templates/environments/network-environment.yaml \
    -e /usr/share/openstack-tripleo-heat-templates/environments/net-single-nic-with-vlans.yaml \
    ...