tacker-specs/specs/zed/support_multi_artifact_of_ansible_driver.rst

Support multi artifacts of ansible driver

https://blueprints.launchpad.net/tacker/+spec/add-ansible-mgmt-driver-sample

We'll be able to use the configuration of multi deployment patterns.

Problem description

The Ansible Driver has only one configuration information for the VDU. This configuration information is defined in the implementation key.

Note

implementation key is defined in TOSCA Simple Profile 3.6.14¹.

This parameter cannot have multiple values, it has a single value. It is executed according to this definition at the start and end of each VNF lifecycle.

node_templates:
  VNF:
    type: SAMPLE.VNF
    properties:
      flavour_description: 'n-vnf'
      vnfm_info:
        - Tacker
    interfaces:
      Vnflcm:
        instantiate: []
        instantiate_start: []
        instantiate_end:
          implementation: ansible_driver
    ...
    artifacts:
      ansible_driver:
        description: Management driver plugin
        type: tosca.artifacts.Implementation.Python
        file: /opt/stack/tacker/tacker/vnfm/mgmt_drivers/ansible/ansible.py

If we want the different configurations for VNFD of different deployment flavor, we need to implement the conditional branch within a Driver or provide the another Driver. However, these methods increase the specificity of the Driver.

We think of ways to ensure the versatility of Driver and propose the following change.

Proposed change

The proposed change is to implement the primary and dependencies keys defined by TOSCA.

primary can define the primary script.

dependencies can define a secondary script that it's referenced by the primary script.

If you implemented this dependency, you would define it as follows :

node_templates:
  VNF:
    type: SAMPLE.VNF
    properties:
      flavour_description: 'n-vnf'
      vnfm_info:
        - Tacker
    interfaces:
      Vnflcm:
        instantiate: []
        instantiate_start:
          implementation:
            primary: ansible_driver
            dependencies:
              - mgmt-drivers-ansible-config-start
        instantiate_end:
          implementation:
            primary: ansible_driver
            dependencies:
              - mgmt-drivers-ansible-config-end
    ...
    artifacts:
      ansible_driver:
        description: Management driver plugin
        type: tosca.artifacts.Implementation.Python
        file: /opt/stack/tacker/tacker/vnfm/mgmt_drivers/ansible/ansible.py
      mgmt-drivers-ansible-config-start:
        description: Management driver config_start.yaml
        type: tosca.artifacts.Implementation.Yaml
        file: ../ScriptAnsible/config_start.yaml
      mgmt-drivers-ansible-config-end:
        description: Management driver config_end.yaml
        type: tosca.artifacts.Implementation.Yaml
        file: ../ScriptAnsible/config_end.yaml

primary defines the script that has run management capabilities, and dependencies defines the script that performs the actual injection. These definitions allow for flexible configuration by the user.

Note

This spec also keep supporting the backward compatibility that single artifact format currently used by VNFD.

How to use

The Ansible Driver uses a yaml file. However, the yaml definition isn't defined in OASIS and cannot be used as it is by Tacker that refer to definition file of OASIS. To use the yaml file, we create the following definition file.

example: additional_type.yaml

tosca_definitions_version: tosca_simple_yaml_1_2
description: yaml types definitions version 0.0.1

metadata:
  template_name: additional_type
  template_author: ---
  template_version: 0.0.1

artifact_types:
  tosca.artifacts.Implementation.Yaml:
    derived_from: tosca.artifacts.Implementation
    description: artifacts for Yaml
    mime_type: application/x-yaml
    file_ext: [yaml]

After creation of this file, we put the this file in the Definitions folder of VNF Package.

example

VNF Package
|
+--TOSCA-Metadata
|  +--TOSCA.meta
|
+--Definitions
|  +--etsi_nfv_sol001_common_types.yaml
|  +--etsi_nfv_sol001_vnfd_types.yaml
|  +--helloworld3_df_simple.yaml
|  +--helloworld3_top.vnfd.yaml
|  +--helloworld3_types.yaml
|  +--additional_type.yaml               <<< add file
|
+--Files
|  +--images
|     +--cirros-0.5.2-x86_64-disk.img
|
+--Drivers
|  +--vnflcm_noop.py
|
+--UserData
   +--__init__.py
   +--lcm_user_data.py

The VNFD imports this definition file at imports section.

Also, the VNFD cannot read this definition file simply by storing it. To be able to read this definition file, we add the following configuration to the VNFD.

tosca_definitions_version: tosca_simple_yaml_1_2

description: Simple deployment flavour for Sample VNF

imports:
  - etsi_nfv_sol001_common_types.yaml
  - etsi_nfv_sol001_vnfd_types.yaml
  - helloworld3_types.yaml
  - additional_type.yaml                  <<< import file

After the bellow settings, you can perform the VNF LCM.

Alternatives

None

Data model impact

None

REST API impact

None

Security impact

None

Notifications impact

None

Other end user impact

None

Performance Impact

None

Other deployer impact

None

Developer impact

None

Implementation

Assignee(s)

Primary assignee:

Wataru Juso <w-juso@nec.com>

Other contributors:

Aldinson C. Esto <esto.aln@nec.com>

Pooja Singla <pooja.singla@india.nec.com>

Work Items

• Enable understanding of primary and dependencies at tosca-parser
• Enable understanding of primary and dependencies at schema of tacker
• Extend method that get implementation information

Dependencies

None

Testing

None

Documentation Impact

• Modifying User Documentation of Ansible Driver

References

---

1. https://docs.oasis-open.org/tosca/TOSCA-Simple-Profile-YAML/v1.2/os/TOSCA-Simple-Profile-YAML-v1.2-os.html↩︎