Deploying with Custom Networks¶

Default networks¶

TripleO offers a default network topology when deploying with network isolation enabled, and this is reflected in the network_data.yaml file in tripleo-heat-templates.

These default networks are as follows:

• External - External network traffic (disabled by default for Compute/Storage nodes)
• InternalApi - Internal API traffic, most intra-service traffic uses this network by default
• Storage - Storage traffic
• StorageMgmt - Storage management traffic (such as replication traffic between storage nodes)
• Tenant - Tenant networks for compute workloads running on the cloud

Deploying with custom networks¶

Each network is defined in the network_data.yaml file. There is a sample file in /usr/share/openstack-tripleo-heat-templates, or the tripleo-heat-templates git repository which can be copied and modified as needed.

The network_data.yaml file contains a list of networks, with definitions like:

- name: CustomNetwork
  vip: false
  name_lower: custom_network
  ip_subnet: '172.16.6.0/24'
  allocation_pools: [{'start': '172.16.6.4', 'end': '172.16.6.250'}]
  gateway_ip: '172.16.6.1'

The data in network_data.yaml is used to perform templating with jinja2 such that arbitrary user-defined networks may be added, and the default networks may be modified or removed.

The steps to define your custom networks are:

1. Copy the default network_data.yaml provided by tripleo-heat-templates:

   cp /usr/share/openstack-tripleo-heat-templates/network_data.yaml custom_network_data.yaml
   

2. Modify the custom_network_data.yaml file as required. The network data is a list of networks, where each network contains at least the following items:

   name

   Name of the network (mandatory)

   vip

   Enable creation of a virtual IP on this network

   ip_subnet

   IP/CIDR, e.g. '10.0.0.0/24'

   allocation_pools

   IP range list, e.g. [{'start':'10.0.0.4', 'end':'10.0.0.250'}]

   gateway_ip

   gateway for the network

   vlan (supported in Queens and later)

   Vlan ID for this network.

   Other options are supported, see the documentation in the default network_data.yaml for details.

   Warning

   Currently there is no validation of the network subnet and allocation_pools, so care must be take to ensure these are consistent, and do not conflict with any existing networks, otherwise your deployment may fail or result in unexpected results.

3. Copy network configuration templates, add new networks.

   Prior to Queens the nic config templates are not dynamically generated, so it is necessary to copy those that are in use, and add parameters for any additional networks, for example:

   cp -r /usr/share/openstack-tripleo-heat-templates/network/config/single-nic-vlans custom-single-nic-vlans
   

   Each file in single-nic-vlans will require update to add parameters for each custom network. Copy those that exist for the default networks, and rename to match the name field in custom_network_data.yaml.

Note

In Queens and later the NIC config templates are dynamically generated so this step is only necessary when creating custom NIC config templates, not when just adding a custom network.

4. Adjust your network-environment to reference the modified nic templates.

   It is necessary to adjust the environment paths to match the location of the copied nic templates above:

   cp /usr/share/openstack-tripleo-heat-templates//environments/net-single-nic-with-vlans.yaml custom-net-single-nic-with-vlans.yaml
   

   Edit the paths for each role to reference custom-single-nic-vlans directory created above.

5. To deploy you pass the custom_network_data.yaml file via the -n option to the overcloud deploy, for example:

   openstack overcloud deploy --templates -n custom_network_data.yaml -e custom-net-single-nic-with-vlans.yaml
   

   Note

   It is also possible to copy the entire tripleo-heat-templates tree, and modify the network_data.yaml file in place, then deploy via --templates <copy of tht>.