tacker/doc/source/user/userdata_script.rst

UserData script (VNF LCM v2)

This document describes the requirements of userdata script how to make it for VNF LCM version 2.

Userdata script enables operators to flexibly customize VIM input parameter in LCM operations.

If you would like to know how to deploy VNF using userdata script, please check ETSI NFV-SOL VNF Deployment as VM with LCM Operation User Data or like to know how to make VNF packages including userdata script, please check VNF Package manual.

Requirements

Userdata script must be described according to the following rules.

Userdata class needs to be defined in userdata script file. Any file name and class name are acceptable.

Note

The names of the file and class have to correspond to following request parameters of LCM API, "lcm-operation-user-data", "lcm-operation-user-data-class".

userdata class must inherit "userdata_utils.AbstractUserData", then functions have to be implemented.

Since latest Tacker supports userdata script for only instantiating vnf, def instantiate(req, inst, grant_req, grant, tmp_csar_dir) only can be implemented. Followings are the requirement of def instantiate()

Input of instantiate()

The function can use the following input data. The details of data types are defined in ETSI NFV SOL documents.

• req: InstantiateVnfRequest
• inst: VnfInstance
• grant_req: GrantRequest
• grant: Grants
• tmp_csar_dir: the temporary path of csar expanded by Tacker.

Output of instantiate()

The function must return the following structure. Data are for stack create API in HEAT. The requirements of HEAT API are described in reference of Orchestration Service API v1 "POST /v1/{tenant_id}/stacks"

fields = {'template': value, 'parameters': value, 'files': value}

• template: Dump of top HOT file.
• parameters: Input parameters for Heat API.
• files: Dump of all nested HOT files in the package.

Following shows sample output.

fields = {
            'template': yaml.safe_dump(top_hot),
            'parameters': {'nfv': nfv_dict},
            'files': {}
        }
        for key, value in hot_dict.get('files', {}).items():
            fields['files'][key] = yaml.safe_dump(value)

        return fields

Sample userdata script

If users do not specify the userdata in instantiate VNF request, the default process runs according to the following script.

The script can be used as a sample for making the original userdata script. It obtains HEAT input parameters such as computeFlavourId, vcImageId, locationConstraints, network, subnet, and fixed_ips from VNFD, parameters of Instantiate request and Grant.

../../../tacker/sol_refactored/infra_drivers/openstack/userdata_default.py

The following is sample Base HOT corresponding to above sample userdata script.

top Base HOT

../../../tacker/tests/functional/sol_v2/samples/sample1/contents/BaseHOT/simple/sample1.yaml

nested Base HOT

../../../tacker/tests/functional/sol_v2/samples/sample1/contents/BaseHOT/simple/nested/VDU1.yaml

Utility functions for userdata class

Tacker provides the following utility functions for the userdata script. Following functions can be called in userdata class.

def get_vnfd(vnfd_id, csar_dir)

Get vnfd in yaml format.

vnf_id: vnfid , csar_dir: the path of csar.

It returns an instance of **Vnfd** class.

def init_nfv_dict(hot_template)

Find the parameter specified by get_param in the HOT template and get the dict of the nfv structure for the HEAT input parameter.

hot_template: HOT in yaml format.

It returns the dict of nfv structure.

def get_param_flavor(vdu_name, req, vnfd, grant)

Get flavor of VDU. If Grant contains the flavor, it is returned. Otherwise, flavor is obtained from vnfd and returned.

vdu_name: the name of VDU , req: InstantiateVnfRequest , vnfd: vnfd , grant: Grants

It returns vimFlavourId

def get_param_image(vdu_name, req, vnfd, grant)

Get software image of VDU. If Grant contains the glance-imageId corresponding to the VDU, it is returned. Otherwise, name of software image is obtained from vnfd and returned.

vdu_name: the name of VDU , req: InstantiateVnfRequest , vnfd: vnfd , grant: Grants

It returns image ID or image name.

def get_param_zone(vdu_name, grant_req, grant)

Get zone id of VDU.

vdu_name: the name of VDU , req: InstantiateVnfRequest , vnfd: vnfd , grant: Grants

It returns zone id.

def _get_fixed_ips_from_extcp(extcp)

Get list of fixed address and subnet from extcp. extcp is instantiateVnfRequest > extVirtualLinks > extcps defined in ETSI NFV SOL003.

It returns the list of fixed address and subnet.

def get_param_network(cp_name, grant, req)

Get network resourceId of CP.

cp_name: the name of CP , grant: Grants , req: InstantiateVnfRequest

It returns network resourceId.

def get_param_fixed_ips(cp_name, grant, req)

Get fixed IP addresses of CP.

cp_name: the name of CP , grant: Grants , req: InstantiateVnfRequest

It returns fixed IP address of CP.

def apply_ext_managed_vls(hot_dict, req, grant)

Modify HOT to apply externally provided extmanaged internal virtual link (extmanagedVL).

ExtmanagedVL is created by VNFM when instantiating VNF or externally created and specified by Grants or InstantiateVnfRequest. Since one HOT can correspond to only one of the cases, this function modifies HOT for the former case to for the latter case.

The Following shows the sample HOT description.

• Input HOT

heat_template_version: 2013-05-23
description: 'Simple Base HOT for Sample VNF'

resources:
  VDU1:
    type: OS::Nova::Server
    properties:
      flavor: { get_param: [ nfv, VDU, VDU2, computeFlavourId ] }
      image: { get_param: [ nfv, VDU, VDU2, vcImageId] }
      networks:
      - port:
          get_resource: VDU1_CP1

  VDU1_CP1:
    type: OS::Neutron::Port
    properties:
      network: { get_resource: internalVL1 }

  internalVL1:
    type: OS::Neutron::Net

outputs: {}

• Output HOT

heat_template_version: 2013-05-23
description: 'Simple Base HOT for Sample VNF'

resources:
  VDU1:
    type: OS::Nova::Server
    properties:
      flavor: { get_param: [ nfv, VDU, VDU2, computeFlavourId ] }
      image: { get_param: [ nfv, VDU, VDU2, vcImageId] }
      networks:
      - port:
          get_resource: VDU1_CP1


  VDU1_CP1:
    type: OS::Neutron::Port
    properties:
      network: network_id

outputs: {}

vnfd.get_base_hot(flavour_id)

Get HOT dict.

flavour_id: flavour_id of vnf instance.

It returns HOT dict with the following structure. dict = {'template':tophot, 'Files'{file 1:, file2:...}}

vnf_instance_utils.json_merge_patch(target, patch)

Get the result of json_merge_patch (IETF RFC 7396).

target: merge target , patch: applied patch

It returns the result of json_merge_patch (IETF RFC 7396).