Chapter 10. Custom network interface templates This chapter follows on from the concepts and procedures outlined in Chapter 8, Basic network isolation . The purpose of this chapter is to demonstrate how to create a set of custom network interface template to suit nodes in your environment. This includes: The environment file to enable network isolation ( /usr/share/openstack-tripleo-heat-templates/environments/network-isolation.yaml ). The environment file to configure network defaults ( /usr/share/openstack-tripleo-heat-templates/environments/network-environment.yaml ). Templates to define your NIC layout for each node. The overcloud core template collection contains a set of defaults for different use cases. In this situation, you will render a default a basis for your custom templates. A custom environment file to enable NICs. This example uses a custom environment file ( /home/stack/templates/custom-network-configuration.yaml ) that references your custom interface templates. Any additional environment files to customize your networking parameters. If using customizing your networks, a custom network_data file. If creating additional or custom composable networks, a custom network_data file and a custom roles_data file. 10.1. Custom network architecture The default NIC templates might not suit a specific network configuration. For example, you might want to create your own custom NIC template that suits a specific network layout. You might aim to separate the control services and data services on to separate NICs. In this situation, the service to NIC assignments result in the following mapping: NIC1 (Provisioning): Provisioning / Control Plane NIC2 (Control Group) Internal API Storage Management External (Public API) NIC3 (Data Group) Tenant Network (VXLAN tunneling) Tenant VLANs / Provider VLANs Storage External VLANs (Floating IP/SNAT) NIC4 (Management) Management 10.2. Rendering default network interface templates for customization For the purposes of simplifying the configuration of custom interface templates, this procedure shows you how to render the Jinja2 syntax of a default NIC template. This way you can use the rendered templates as a basis for your custom configuration. Procedure Render a copy of the openstack-tripleo-heat-templates collection using the process-templates.py script: This converts all Jinja2 templates to their rendered YAML versions and saves the results to ~/openstack-tripleo-heat-templates-rendered . If using a custom network file or custom roles file, you can include these files using the -n and -r options respectively. For example: Copy the multiple NIC example: You can edit the template set in custom-nics to suit your own network configuration. 10.3. Network interface architecture This section explores the architecture of the custom NIC templates in custom-nics and provides recommendations on editing them. Parameters The parameters section contains all network configuration parameters for network interfaces. This includes information such as subnet ranges and VLAN IDs. This section should remain unchanged as the Heat template inherits values from its parent template. However, you can modify the values for some parameters using a network environment file. Resources The resources section is where the main network interface configuration occurs. In most cases, the resources section is the only one that requires editing. Each resources section begins with the following header: This runs a script ( run-os-net-config.sh ) that creates a configuration file for os-net-config to use for configuring network properties on a node. The network_config section contains the custom network interface data sent to the run-os-net-config.sh script. You arrange this custom interface data in a sequence based on the type of device. Important If creating custom NIC templates, you must set the run-os-net-config.sh script location to an absolute location for each NIC template. The script is located at /usr/share/openstack-tripleo-heat-templates/network/scripts/run-os-net-config.sh on the undercloud. 10.4. Network interface reference The following sections define the network interface types and the parameters used in each. interface Defines a single network interface. The configuration defines each interface using either the actual interface name ("eth0", "eth1", "enp0s25") or a set of numbered interfaces ("nic1", "nic2", "nic3"). For example: Table 10.1. interface options Option Default Description name Name of the Interface use_dhcp False Use DHCP to get an IP address use_dhcpv6 False Use DHCP to get a v6 IP address addresses A list of IP addresses assigned to the interface routes A list of routes assigned to the interface. See routes . mtu 1500 The maximum transmission unit (MTU) of the connection primary False Defines the interface as the primary interface defroute True Use a default route provided by the DHCP service. Only applies when use_dhcp or use_dhcpv6 is enabled. persist_mapping False Write the device alias configuration instead of the system names dhclient_args None Arguments to pass to the DHCP client dns_servers None List of DNS servers to use for the interface vlan Defines a VLAN. Use the VLAN ID and subnet passed from the parameters section. For example: Table 10.2. vlan options Option Default Description vlan_id The VLAN ID device The parent device to attach the VLAN. Use this parameter when the VLAN is not a member of an OVS bridge. For example, use this parameter to attach the VLAN to a bonded interface device. use_dhcp False Use DHCP to get an IP address use_dhcpv6 False Use DHCP to get a v6 IP address addresses A list of IP addresses assigned to the VLAN routes A list of routes assigned to the VLAN. See routes . mtu 1500 The maximum transmission unit (MTU) of the connection primary False Defines the VLAN as the primary interface defroute True Use a default route provided by the DHCP service. Only applies when use_dhcp or use_dhcpv6 is enabled. persist_mapping False Write the device alias configuration instead of the system names dhclient_args None Arguments to pass to the DHCP client dns_servers None List of DNS servers to use for the VLAN ovs_bond Defines a bond in Open vSwitch to join two or more interfaces together. This helps with redundancy and increases bandwidth. For example: Table 10.3. ovs_bond options Option Default Description name Name of the bond use_dhcp False Use DHCP to get an IP address use_dhcpv6 False Use DHCP to get a v6 IP address addresses A list of IP addresses assigned to the bond routes A list of routes assigned to the bond. See routes . mtu 1500 The maximum transmission unit (MTU) of the connection primary False Defines the interface as the primary interface members A sequence of interface objects to use in the bond ovs_options A set of options to pass to OVS when creating the bond ovs_extra A set of options to to set as the OVS_EXTRA parameter in the bond's network configuration file defroute True Use a default route provided by the DHCP service. Only applies when use_dhcp or use_dhcpv6 is enabled. persist_mapping False Write the device alias configuration instead of the system names dhclient_args None Arguments to pass to the DHCP client dns_servers None List of DNS servers to use for the bond ovs_bridge Defines a bridge in Open vSwitch, which connects multiple interface , ovs_bond , and vlan objects together. The external bridge also uses two special values for parameters: bridge_name , which is replaced with the external bridge name. interface_name , which is replaced with the external interface. For example: Note The OVS bridge connects to the Neutron server in order to get configuration data. If the OpenStack control traffic (typically the Control Plane and Internal API networks) is placed on an OVS bridge, then connectivity to the Neutron server gets lost whenever OVS is upgraded or the OVS bridge is restarted by the admin user or process. This will cause some downtime. If downtime is not acceptable under these circumstances, then the Control group networks should be placed on a separate interface or bond rather than on an OVS bridge: A minimal setting can be achieved, when you put the Internal API network on a VLAN on the provisioning interface and the OVS bridge on a second interface. If you want bonding, you need at least two bonds (four network interfaces). The control group should be placed on a Linux bond (Linux bridge). If the switch does not support LACP fallback to a single interface for PXE boot, then this solution requires at least five NICs. Table 10.4. ovs_bridge options Option Default Description name Name of the bridge use_dhcp False Use DHCP to get an IP address use_dhcpv6 False Use DHCP to get a v6 IP address addresses A list of IP addresses assigned to the bridge routes A list of routes assigned to the bridge. See routes . mtu 1500 The maximum transmission unit (MTU) of the connection members A sequence of interface, VLAN, and bond objects to use in the bridge ovs_options A set of options to pass to OVS when creating the bridge ovs_extra A set of options to to set as the OVS_EXTRA parameter in the bridge's network configuration file defroute True Use a default route provided by the DHCP service. Only applies when use_dhcp or use_dhcpv6 is enabled. persist_mapping False Write the device alias configuration instead of the system names dhclient_args None Arguments to pass to the DHCP client dns_servers None List of DNS servers to use for the bridge linux_bond Defines a Linux bond that joins two or more interfaces together. This helps with redundancy and increases bandwidth. Make sure to include the kernel-based bonding options in the bonding_options parameter. For example: Note that nic2 uses primary: true . This ensures the bond uses the MAC address for nic2 . Table 10.5. linux_bond options Option Default Description name Name of the bond use_dhcp False Use DHCP to get an IP address use_dhcpv6 False Use DHCP to get a v6 IP address addresses A list of IP addresses assigned to the bond routes A list of routes assigned to the bond. See routes . mtu 1500 The maximum transmission unit (MTU) of the connection primary False Defines the interface as the primary interface. members A sequence of interface objects to use in the bond bonding_options A set of options when creating the bond. defroute True Use a default route provided by the DHCP service. Only applies when use_dhcp or use_dhcpv6 is enabled. persist_mapping False Write the device alias configuration instead of the system names dhclient_args None Arguments to pass to the DHCP client dns_servers None List of DNS servers to use for the bond linux_bridge Defines a Linux bridge, which connects multiple interface , linux_bond , and vlan objects together. The external bridge also uses two special values for parameters: bridge_name , which is replaced with the external bridge name. interface_name , which is replaced with the external interface. For example: Table 10.6. linux_bridge options Option Default Description name Name of the bridge use_dhcp False Use DHCP to get an IP address use_dhcpv6 False Use DHCP to get a v6 IP address addresses A list of IP addresses assigned to the bridge routes A list of routes assigned to the bridge. See routes . mtu 1500 The maximum transmission unit (MTU) of the connection members A sequence of interface, VLAN, and bond objects to use in the bridge defroute True Use a default route provided by the DHCP service. Only applies when use_dhcp or use_dhcpv6 is enabled. persist_mapping False Write the device alias configuration instead of the system names dhclient_args None Arguments to pass to the DHCP client dns_servers None List of DNS servers to use for the bridge routes Defines a list of routes to apply to a network interface, VLAN, bridge, or bond. For example: Option Default Description ip_netmask None IP and netmask of the destination network. default False Sets this this route to a default route. Equivalent to setting ip_netmask: 0.0.0.0/0 . next_hop None The IP address of the router used to reach the destination network. 10.5. Example network interface layout The following snippet for a possible Controller node NIC template demonstrates how to configure the custom network scenario to keep the control group apart from the OVS bridge: This template uses four network interfaces and assigns a number of tagged VLAN devices to the numbered interfaces, nic1 to nic4 . On nic3 it creates the OVS bridge that hosts the Storage and Tenant networks. As a result, it creates the following layout: NIC1 (Provisioning): Provisioning / Control Plane NIC2 (Control Group) Internal API Storage Management External (Public API) NIC3 (Data Group) Tenant Network (VXLAN tunneling) Tenant VLANs / Provider VLANs Storage External VLANs (Floating IP/SNAT) NIC4 (Management) Management 10.6. Network interface template considerations for custom networks When using composable networks, the process-templates.py script renders the static templates to include networks and roles defined in your network_data and roles_data files. Check the rendered NIC templates and ensure it contains: Static file for each roles, including custom composable networks. Each static file for each role contains the correct network definitions. Each static file requires all the parameter definitions for any custom networks even if the network is not used on the role. Check to make sure the rendered templates contain these parameters. For example, if a StorageBackup network is added to only the Ceph nodes, the parameters section in NIC configuration templates for all roles must also include this definition: You can also include the parameters definitions for VLAN IDs and/or gateway IP, if needed: The IpSubnet parameter for the custom network appears in the parameter definitions for each role. However, since the Ceph role might be the only role that uses the StorageBackup network, only the NIC configuration template for the Ceph role would make use of the StorageBackup parameters in the network_config section of the template. 10.7. Custom network environment file The custom network environment file (in this case, /home/stack/templates/custom-network-configuration.yaml ) is a Heat environment file that describes the Overcloud's network environment and points to the custom network interface configuration templates. You can define the subnets and VLANs for your network along with IP address ranges. You can then customize these values for the local environment. The resource_registry section contains references to the custom network interface templates for each node role. Each resource registered uses the following format: OS::TripleO::[ROLE]::Net::SoftwareConfig: [FILE] [ROLE] is the role name and [FILE] is the respective network interface template for that particular role. For example: The parameter_defaults section contains a list of parameters that define the network options for each network type. 10.8. Network environment parameters The following table is a list of parameters you can use in a network environment file's parameter_defaults section to override the default parameter values in your NIC templates. Parameter Description Type ControlPlaneDefaultRoute The IP address of the router on the Control Plane, which is used as a default route for roles other than the Controller nodes by default. Set to the undercloud IP if using IP masquerade instead of a router. string ControlPlaneSubnetCidr The CIDR netmask of the IP network used on the Control Plane. If the Control Plane network uses 192.168.24.0/24, the CIDR is 24 . string (though is always a number) *NetCidr The full network and CIDR netmask for a particular network. The default is automatically set to the network's ip_subnet setting in the network_data file. For example: InternalApiNetCidr: 172.16.0.0/24 string *AllocationPools "The IP allocation range for a particular network. The default is automatically set to the network's allocation_pools setting in the network_data file. For example: InternalApiAllocationPools: [{'start': '172.16.0.10', 'end': '172.16.0.200'}] hash *NetworkVlanID The node's VLAN ID for on a particular network. The default is set automatically to the network's vlan setting in the network_data file. For example: InternalApiNetworkVlanID: 201 number *InterfaceDefaultRoute The router address for a particular network, which you can use as a default route for roles or used for routes to other networks. The default is automatically set to the network's gateway_ip setting in the network_data file. For example: InternalApiInterfaceDefaultRoute: 172.16.0.1 string DnsServers A list of DNS servers added to resolv.conf. Usually allows a maximum of 2 servers. comma delimited list EC2MetadataIp The IP address of the metadata server used to provision overcloud nodes. Set to the IP address of the undercloud on the Control Plane. string BondInterfaceOvsOptions The options for bonding interfaces. For example: BondInterfaceOvsOptions: "bond_mode=balance-slb" string NeutronExternalNetworkBridge Legacy value for the name of the external bridge to use for OpeNStack Networking (neutron). This value is empty by default, which allows for multiple physical bridges to be defined in the NeutronBridgeMappings . This should not normally be overridden. string NeutronFlatNetworks Defines the flat networks to configure in neutron plugins. Defaults to "datacentre" to permit external network creation. For example: NeutronFlatNetworks: "datacentre" string NeutronBridgeMappings The logical to physical bridge mappings to use. Defaults to mapping the external bridge on hosts ( br-ex ) to a physical name ( datacentre ). You would refer to the logical name when creating OpenStack Networking (neutron) provider networks or floating IP networks. For example NeutronBridgeMappings: "datacentre:br-ex,tenant:br-tenant" string NeutronPublicInterface Defines the interface to bridge onto br-ex for network nodes when not using network isolation. Usually not used except in small deployments with only two networks. For example: NeutronPublicInterface: "eth0" string NeutronNetworkType TThe tenant network type for OpenStack Networking (neutron). To specify multiple values, use a comma separated list. The first type specified is used until all available networks are exhausted, then the type is used. For example: NeutronNetworkType: "vxlan" string NeutronTunnelTypes The tunnel types for the neutron tenant network. To specify multiple values, use a comma separated string. For example: NeutronTunnelTypes: 'gre,vxlan ' string / comma separated list NeutronTunnelIdRanges Ranges of GRE tunnel IDs to make available for tenant network allocation. For example: NeutronTunnelIdRanges "1:1000" string NeutronVniRanges Ranges of VXLAN VNI IDs to make available for tenant network allocation. For example: NeutronVniRanges: "1:1000" string NeutronEnableTunnelling Defines whether to enable or completely disable all tunnelled networks. Leave this enabled unless you are sure you will never want to create tunelled networks. Defaults to enabled. Boolean NeutronNetworkVLANRanges The ML2 and Open vSwitch VLAN mapping range to support. Defaults to permitting any VLAN on the datacentre physical network. To specify multiple values, use a comma separated list. For example: NeutronNetworkVLANRanges: "datacentre:1:1000,tenant:100:299,tenant:310:399" string NeutronMechanismDrivers The mechanism drivers for the neutron tenant network. Defaults to "ovn". To specify multiple values, use a comma-separated string. For example: NeutronMechanismDrivers: 'openvswitch,l2population' string / comma separated list 10.9. Example custom network environment file The following is an example of an environment file to enable your NIC templates and set custom parameters. 10.10. Enabling network isolation with custom NICs This procedure show how to enable network isolation using custom NIC templates. Procedure When running the openstack overcloud deploy command, make sure to include: The custom network_data file. The rendered file name of the default network isolation. The rendered file name of the default network environment file. The custom environment network configuration that includes resource references to your custom NIC templates. Any additional environment files relevant to your configuration. For example: Include the network-isolation.yaml file first, then the network-environment.yaml file. The subsequent custom-network-configuration.yaml overrides the OS::TripleO::[ROLE]::Net::SoftwareConfig resources from the two files.. If using composable networks, include the network_data and roles_data files with this command.

Commands:
cd /usr/share/openstack-tripleo-heat-templates ./tools/process-templates.py -o ~/openstack-tripleo-heat-templates-rendered
./tools/process-templates.py -o ~/openstack-tripleo-heat-templates-rendered -n /home/stack/network_data.yaml -r /home/stack/roles_data.yaml
cp -r ~/openstack-tripleo-heat-templates-rendered/network/config/multiple-nics/ ~/templates/custom-nics/
resources: OsNetConfigImpl: type: OS::Heat::SoftwareConfig properties: group: script config: str_replace: template: get_file: /usr/share/openstack-tripleo-heat-templates/network/scripts/run-os-net-config.sh params: USDnetwork_config: network_config:
- type: interface name: nic2
- type: vlan vlan_id:{get_param: ExternalNetworkVlanID} addresses: - ip_netmask: {get_param: ExternalIpSubnet}
- type: ovs_bond name: bond1 members: - type: interface name: nic2 - type: interface name: nic3
- type: ovs_bridge name: bridge_name addresses: - ip_netmask: list_join: - / - - {get_param: ControlPlaneIp} - {get_param: ControlPlaneSubnetCidr} members: - type: interface name: interface_name - type: vlan device: bridge_name vlan_id: {get_param: ExternalNetworkVlanID} addresses: - ip_netmask: {get_param: ExternalIpSubnet}
- type: linux_bond name: bond1 members: - type: interface name: nic2 primary: true - type: interface name: nic3 bonding_options: "mode=802.3ad"
- type: linux_bridge name: bridge_name addresses: - ip_netmask: list_join: - / - - {get_param: ControlPlaneIp} - {get_param: ControlPlaneSubnetCidr} members: - type: interface name: interface_name - type: vlan device: bridge_name vlan_id: {get_param: ExternalNetworkVlanID} addresses: - ip_netmask: {get_param: ExternalIpSubnet}
- type: interface name: nic2 routes: - ip_netmask: 10.1.2.0/24 default: true next_hop: get_param: EC2MetadataIp
resources: OsNetConfigImpl: type: OS::Heat::SoftwareConfig properties: group: script config: str_replace: template: get_file: /usr/share/openstack-tripleo-heat-templates/network/scripts/run-os-net-config.sh params: USDnetwork_config: network_config: # NIC 1 - Provisioning - type: interface name: nic1 use_dhcp: false addresses: - ip_netmask: list_join: - / - - get_param: ControlPlaneIp - get_param: ControlPlaneSubnetCidr routes: - ip_netmask: 169.254.169.254/32 next_hop: get_param: EC2MetadataIp # NIC 2 - Control Group - type: interface name: nic2 use_dhcp: false - type: vlan device: nic2 vlan_id: get_param: InternalApiNetworkVlanID addresses: - ip_netmask: get_param: InternalApiIpSubnet - type: vlan device: nic2 vlan_id: get_param: StorageMgmtNetworkVlanID addresses: - ip_netmask: get_param: StorageMgmtIpSubnet - type: vlan device: nic2 vlan_id: get_param: ExternalNetworkVlanID addresses: - ip_netmask: get_param: ExternalIpSubnet routes: - default: true next_hop: get_param: ExternalInterfaceDefaultRoute # NIC 3 - Data Group - type: ovs_bridge name: bridge_name dns_servers: get_param: DnsServers members: - type: interface name: nic3 primary: true - type: vlan vlan_id: get_param: StorageNetworkVlanID addresses: - ip_netmask: get_param: StorageIpSubnet - type: vlan vlan_id: get_param: TenantNetworkVlanID addresses: - ip_netmask: get_param: TenantIpSubnet # NIC 4 - Management - type: interface name: nic4 use_dhcp: false addresses: - ip_netmask: {get_param: ManagementIpSubnet} routes: - default: true next_hop: {get_param: ManagementInterfaceDefaultRoute}
parameters: StorageBackupIpSubnet: default: '' description: IP address/subnet on the external network type: string
parameters: StorageBackupNetworkVlanID: default: 60 description: Vlan ID for the management network traffic. type: number StorageBackupDefaultRoute: description: The default route of the storage backup network. type: string
USDnetwork_config: network_config: - type: interface name: nic1 use_dhcp: false addresses: - ip_netmask: get_param: StorageBackupIpSubnet
resource_registry: OS::TripleO::Controller::Net::SoftwareConfig: /home/stack/templates/custom-nics/controller.yaml
resource_registry: OS::TripleO::BlockStorage::Net::SoftwareConfig: /home/stack/templates/nic-configs/cinder-storage.yaml OS::TripleO::Compute::Net::SoftwareConfig: /home/stack/templates/nic-configs/compute.yaml OS::TripleO::Controller::Net::SoftwareConfig: /home/stack/templates/nic-configs/controller.yaml OS::TripleO::ObjectStorage::Net::SoftwareConfig: /home/stack/templates/nic-configs/swift-storage.yaml OS::TripleO::CephStorage::Net::SoftwareConfig: /home/stack/templates/nic-configs/ceph-storage.yaml parameter_defaults: # Gateway router for the provisioning network (or Undercloud IP) ControlPlaneDefaultRoute: 192.0.2.254 # The IP address of the EC2 metadata server. Generally the IP of the Undercloud EC2MetadataIp: 192.0.2.1 # Define the DNS servers (maximum 2) for the overcloud nodes DnsServers: ["8.8.8.8","8.8.4.4"] NeutronExternalNetworkBridge: "''"
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 /home/stack/templates/custom-network-configuration.yaml