Deploying with Custom Networks

TripleO offers the option of deploying with a user-defined list of networks, where each network can be enabled (or not) for each role (group of servers) in the deployment.

Default networks

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

Victoria and prior releases

In Victoria and prior releases the default network topology 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 are sample files in /usr/share/openstack-tripleo-heat-templates/network-data-samples, 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
  subnets:
    custom_network_subnet:
      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

Victoria and prior releases

Victoria and releases prior to it used a slightly different network_data YAML.

- 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 the network_data YAML definition is used to create and update the network and subnet API resources in Neutron on the undercloud. It is also 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 one of the sample network_data YAML definitions provided by tripleo-heat-templates, for example:

    cp /usr/share/openstack-tripleo-heat-templates/network-data-samples/default-network-isolation.yaml \
      custom_network_data.yaml
    

    Victoria and prior releases

    In Victoria and earlier releases the sample network data YAML was in a different location.

    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

    vlan

    Vlan ID for this network. (supported in Queens and later)

    subnets

    Dictionary’s, one or more subnet definition items keyed by the subnet name.

    subnet_name

    Name of the subnet

    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

    See Network data YAML options for a list of all documented options for the network_data YAML network definition.

    Victoria and prior releases

    Victoria and earlier releases requires the first subnet definition not to be in the subnets dictionary.

    name

    Name of the network (mandatory)

    vip

    Enable creation of a virtual IP on this network

    vlan

    Vlan ID for this network. (supported in Queens and later)

    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

    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 Victoria, Heat templates were used to define nic configuration templates. With the Victoria release, Ansible jinja2 templates were introduced, and replaced the heat templates.

    The nic configuration examples in tripleo-heat-templates was ported to Ansible jinja2 templates located in the tripleo_network_config role in tripleo-ansible.

    If one of the shipped examples match, use it! If not, be inspired by the shipped examples and create a set of custom Ansible jinja2 templates. Please refer to the Creating Custom Interface Templates documentation page which provide a detailed guide on how to create custom Ansible jinja2 nic config templates.

    For example, copy a sample template to a custom location:

    cp -r /usr/share/ansible/roles/tripleo_network_config/templates/single_nic_vlans custom-single-nic-vlans
    

    Modify the templates in custom-single-nic-vlans to match your needs.

    Ussuri and prior releases

    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 updating 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. Set your environment overrides to enable your nic config templates.

    Create or update an existing environment file and set the parameter values to enable your custom nic config templates, for example create a file custom-net-single-nic-with-vlans.yaml with these parameter settings:

    parameter_defaults:
      ControllerNetworkConfigTemplate: '/path/to/custom-single-nic-vlans/single_nic_vlans.j2'
      CephStorageNetworkConfigTemplate: '/path/to/custom-single-nic-vlans/single_nic_vlans_storage.j2'
      ComputeNetworkConfigTemplate: '/path/to/custom-single-nic-vlans/single_nic_vlans.j2'
    
  5. Create the networks on the undercloud and generate the networks-deployed-environment.yaml which will be used as an environment file when deploying the overcloud.

    openstack overcloud network provision \
      --output networks-deployed-environment.yaml \
      custom_network_data.yaml
    

    Victoria and prior releases

    For Victoria and earlier releases skip this step.

    There was no command openstack overcloud network provision in these releases. Network resources was created as part of the overcloud heat stack.

  6. 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 networks-deployed-environment.yaml \
      -e custom-net-single-nic-with-vlans.yaml
    

    Victoria and prior releases

    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>.

Network data YAML options

name

Name of the network

type: string

name_lower

(optional) Lower case name of the network

type: string

default: name.lower()

dns_domain

(optional) Dns domain name for the network

type: string

mtu

(optional) Set the maximum transmission unit (MTU) that is guaranteed to pass through the data path of the segments in the network.

type: number

default: 1600

service_net_map_replace

(optional) if name_lower is set to a custom name this should be set to original default (optional). This field is only necessary when changing the default network names, not when adding a new custom network.

type: string

Warning

Please avoid using this option, the correct solution when changing a name_lower of one of the default networks is to also update the ServiceNetMap parameter to use the same custom name_lower.

ipv6

(optional)

type: boolean

default: false

vip

(optional) Enable creation of a virtual IP on this network

type: boolean

default: false

subnets

A map of subnets for the network. The collection should contain keys which define the subnet name. The value for each item is a subnet definition.

Example:

subnets:
  subnet_name_a:
    ip_subnet: 192.0.2.0/24
    allocation_pools:
      - start: 192.0.2.50
        end: 192.0.2.99
    gateway_ip: 192.0.2.1
    vlan: 102
  subnet_name_b:
    ip_subnet: 198.51.100.0/24
    allocation_pools:
      - start: 198.51.100.50
        end: 198.51.100.99
    gateway_ip: 198.51.100.1
    vlan: 101

See Options for network data YAML subnet definitions for a list of all documented sub-options for the subnet definitions.

type: dictonary

Options for network data YAML subnet definitions

ip_subnet

IPv4 CIDR block notation for this subnet. For example: 192.0.2.0/24

type: string

Note

Optional if ipv6_subnet is specified.

ipv6_subnet

IPv6 CIDR block notation for this subnet. For example: 2001:db8:fd00:1000::/64

type: string

Note

Optional if ip_subnet is specified.

gateway_ip

(optional) The gateway IPv4 address

type: string

gateway_ipv6

(optional) The gateway IPv6 address

allocation_pools

(optional) The start and end addresses for the subnets IPv4 allocation pools.

type: list

elements: dictonary

suboptions
start

Start address for the allocation pool.

type: string

end

End address for the allocation pool.

type: string

Example:

allocation_pools:
  - start: 192.0.2.50
    end: 192.0.2.99
  - start: 192.0.2.150
    end: 192.0.2.199
ipv6_allocation_pools

(optional) The start and end addresses for the subnets IPv6 allocation pools.

type: list

elements: dictonary

suboptions
start

Start address for the allocation pool.

type: string

end

End address for the allocation pool.

type: string

Example:

allocation_pools:
  - start: 2001:db8:fd00:1000:100::1
    end: 2001:db8:fd00:1000:199::1
  - start: 2001:db8:fd00:1000:300::1
    end: 2001:db8:fd00:1000:399::1
routes

(optional) List of networks that should be routed via network gateway. A single /16 supernet route could be used for 255 smaller /24 subnets.

type: list

elements: dictonary

suboptions
destination

Destination network, for example: 198.51.100.0/24

type: string

nexthop

IP address of the router to use for the destination network, for example: 192.0.2.1

type: string

Example:

routes:
  - destination: 198.51.100.0/24
    nexthop: 192.0.2.1
  - destination: 203.0.113.0/24
    nexthost: 192.0.2.1
routes_ipv6

(optional) List of IPv6 networks that should be routed via network gateway.

type: list

elements: dictonary

suboptions
destination

Destination network, for example: 2001:db8:fd00:2000::/64

type: string

nexthop

IP address of the router to use for the destination network, for example: 2001:db8:fd00:1000::1

type: string

Example:

routes:
  - destination: 2001:db8:fd00:2000::/64
    nexthop: 2001:db8:fd00:1000:100::1
  - destination: 2001:db8:fd00:3000::/64
    nexthost: 2001:db8:fd00:1000:100::1
vlan

(optional) vlan ID for the network

type: number