VNFD Template Parameterization¶
Overview¶
Parameterization allows for the ability to use a single VNFD to be deployed multiple times with different values for the VDU parameters provided at deploy time. In contrast, a non-parameterized VNFD has static values for the parameters that might limit the number of concurrent VNFs that can be deployed using a single VNFD. For example, deploying an instance of a non-parameterized template that has fixed IP addresses specified for network interface a second time without deleting the first instance of VNF would lead to an error.
Non-parameterized VNFD template¶
Find below an example of a non-parameterized VNFD where the text italicized are the VDU parameters and text in bold are the values for those VDU parameters that get applied to the VDU when this template is deployed. The next section will illustrate how the below non-parameterized template can be parameterized and re-used for deploying multiple VNFs.
Here is the sample template:
tosca_definitions_version: tosca_simple_profile_for_nfv_1_0_0
description: VNF TOSCA template with input parameters
metadata:
template_name: sample-tosca-vnfd
topology_template:
node_templates:
VDU1:
type: tosca.nodes.nfv.VDU.Tacker
properties:
image: cirros-0.3.4-x86_64-uec
flavor: m1.tiny
availability_zone: nova
mgmt_driver: noop
config: |
param0: key1
param1: key2
CP1:
type: tosca.nodes.nfv.CP.Tacker
properties:
management: True
anti_spoofing_protection: false
requirements:
- virtualLink:
node: VL1
- virtualBinding:
node: VDU1
CP2:
type: tosca.nodes.nfv.CP.Tacker
properties:
anti_spoofing_protection: false
requirements:
- virtualLink:
node: VL2
- virtualBinding:
node: VDU1
CP3:
type: tosca.nodes.nfv.CP.Tacker
properties:
anti_spoofing_protection: false
requirements:
- virtualLink:
node: VL3
- virtualBinding:
node: VDU1
VL1:
type: tosca.nodes.nfv.VL
properties:
network_name: net_mgmt
vendor: Tacker
VL2:
type: tosca.nodes.nfv.VL
properties:
network_name: net0
vendor: Tacker
VL3:
type: tosca.nodes.nfv.VL
properties:
network_name: net1
vendor: Tacker
Parameterized VNFD template¶
This section will walk through parameterizing the template in above section for re-use and allow for deploying multiple VNFs with the same template. (Note: All the parameters italicized in the above template could be parameterized to accept values at deploy time). For the current illustration purpose, we will assume that an end user would want to be able to supply different values for the parameters image_name, flavor, network, management, pkt_in_network, pkt_out_network, vendor, during each deploy of the VNF.
The next step is to substitute the identified parameter values that will be provided at deploy time with { get_input: <param_name>}. For example, the instance_type: cirros-0.3.4-x86_64-uec would now be replaced as: image: {get_input: image_name}. The get_input is a reserved keyword in the template that indicates value will be supplied at deploy time for the parameter instance_type. The image_name is the variable that will hold the value for the parameter image in a parameters value file that will be supplied at VNF deploy time.
The template in above section will look like below when parameterized for image_name, flavor, network, management and remaining parameters.
Here is the sample template:
tosca_definitions_version: tosca_simple_profile_for_nfv_1_0_0
description: VNF TOSCA template with input parameters
metadata:
template_name: sample-tosca-vnfd
topology_template:
inputs:
image_name:
type: string
description: Image Name
flavor:
type: string
description: Flavor Information
zone:
type: string
description: Zone Information
network:
type: string
description: management network
management:
type: string
description: management network
pkt_in_network:
type: string
description: In network
pkt_out_network:
type: string
description: Out network
vendor:
type: string
description: Vendor information
node_templates:
VDU1:
type: tosca.nodes.nfv.VDU.Tacker
properties:
image: { get_input: image_name}
flavor: {get_input: flavor}
availability_zone: { get_input: zone }
mgmt_driver: noop
config: |
param0: key1
param1: key2
CP1:
type: tosca.nodes.nfv.CP.Tacker
properties:
management: { get_input: management }
anti_spoofing_protection: false
requirements:
- virtualLink:
node: VL1
- virtualBinding:
node: VDU1
CP2:
type: tosca.nodes.nfv.CP.Tacker
properties:
anti_spoofing_protection: false
requirements:
- virtualLink:
node: VL2
- virtualBinding:
node: VDU1
CP3:
type: tosca.nodes.nfv.CP.Tacker
properties:
anti_spoofing_protection: false
requirements:
- virtualLink:
node: VL3
- virtualBinding:
node: VDU1
VL1:
type: tosca.nodes.nfv.VL
properties:
network_name: { get_input: network }
vendor: {get_input: vendor}
VL2:
type: tosca.nodes.nfv.VL
properties:
network_name: { get_input: pkt_in_network }
vendor: {get_input: vendor}
VL3:
type: tosca.nodes.nfv.VL
properties:
network_name: { get_input: pkt_out_network }
vendor: {get_input: vendor}
Parameter values file at VNF deploy¶
The below illustrates the parameters value file to be supplied containing the values to be substituted for the above parameterized template above during VNF deploy.
image_name: cirros-0.3.4-x86_64-uec
flavor: m1.tiny
zone: nova
network: net_mgmt
management: True
pkt_in_network: net0
pkt_out_network: net1
vendor: Tacker
Note
IP address values for network interfaces should be in the below format in the parameters values file:
- param_name_value:
- - xxx.xxx.xxx.xxx
Key Summary¶
Parameterize your VNFD if you want to re-use for multiple VNF deployments.
Identify parameters that would need to be provided values at deploy time and substitute value in VNFD template with {get_input: <param_value_name>}, where ‘param_value_name’ is the name of the variable that holds the value in the parameters value file.
Supply a parameters value file in yaml format each time during VNF deployment with different values for the parameters.
An example of a vnf-create python-tackerclient command specifying a parameterized template and parameter values file would like below:
tacker vnf-create --vnfd-name <vnfd_name> --param-file <param_yaml_file> <vnf_name>Specifying a parameter values file during VNF creation is also supported in Horizon UI.
Sample VNFD parameterized templates and parameter values files can be found at https://github.com/openstack/tacker/tree/master/samples/tosca-templates/vnfd.