REST API for VNF based on ETSI NFV-SOL specification

https://blueprints.launchpad.net/tacker/+spec/support-etsi-nfv-specs

ETSI specifications within the NFV Architecture Framework [1] describe the main aspects of NFV development and usage based on of the industry needs, feedback from SDN/NFV vendors and telecom operators. These specifications include the REST API and data model architecture which is used by NFV users and developers in related products.

Problem description

At the moment, Tacker uses its own API which describes CRUD operations with components based on ETSI NFV MANO standards.

However, these operations are not aligned with the current ETSI NFV data-model. As a result, there might be lack of compatibility with 3rd party VNFs [2], as they are developed according to ETSI NFV specifications. In addition, the mismatch with the generally accepted specifications brings additional complexity for integrations with 3rd party ETSI-compliant systems thereby increasing time and efforts for brownfield deployments. ETSI NVF specifications describe not just internal logic of MANO, but it also interacts with 3rd party systems as VIM, SDN Controllers, VNFs, EMSs and OSS and are actively used by multiple vendors in the market. Support of key ETSI NFV specifications will significantly reduce efforts for Tacker integration into Telecom production networks and also will simplify further development and support of future standards.

Proposed change

Introduce a new interface to invoke VNF lifecycle management operations of VNF instances towards the VNFM.

The operations provided through this interface are:

• Create VNF Identifier

• Query VNF

• List VNF Identifier

• Delete VNF Identifier

• Instantiate VNF

• Heal VNF

• Terminate VNF

1) Flow of creation of a VNF instance resource

The procedure consists of the following steps as illustrated in above sequence:

• The Consumer sends a POST request to the “VNF Instances” resource including in the payload body a data structure of type “CreateVnfRequest”.

• The VNFM creates a new VNF instance resource in NOT_INSTANTIATED state, and the associated VNF instance identifier. Some attribute in a VNF instance resource come from VNF package given in “CreateVnfRequest”.

• The VNFM returns a 201 Created response containing a representation of the VNF instance resource just created by the VNFM, and provides the URI of the newly-created resource in the “Location” HTTP header.

Note

VNF instance resource requires VNF package registerd in advance. And also VNFD in VNF package must comply to NFV-SOL001.

Postcondition: Upon successful completion, the VNF instance resource has been created in “NOT_INSTANTIATED” state.

2) Flow of Instantiation of a VNF instance

The procedure consists of the following steps as illustrated in above sequence:

1. During the pre instantiation process of VNF, VNFM will create images as described in the VNFD of the given deployment flavor using Glance client. According to ETSI NFV documents, NFVO should hold image information and register images to VIM directly, then, NFVO should provide image ids to VNFM with Grant API, but in U release, VNFM will register images directly to VIM.

2. Openstack driver will create stack using Heat and wait till it’s status become CREATE_COMPLETE.

3. VnfLcmDriver will update DB for instantiatedState as INSTANTIATED, vnf_state as STARTED and vnf package usage_state as IN_USE accordingly.

Note

External network such as extVirtualLinks, extLinkPorts and extManagedVirtualLinks are assumed to be created by customer. According to ETSI NFV documents, these networks should be created by NFVO, however, functions related to NFVO will be future work. So, Tacker will not create external networks.

3) Flow of Heal of a VNF instance

Precondition: VNF instance in “INSTANTIATED” state.

The procedure consists of the following steps as illustrated in above sequence:

1. Consumer sends a POST request to the “HEAL VNF Instance” resource.

2. OpenstackDriver will send request to HEAT to mark resource unhealthy based on HEAL Request.

3. OpenstackDriver will send request to HEAT to update the stack.

4. OpenstackDriver will send request to HEAT to get the updated resource data of the stack.

5. VnfLcmDriver will update the details of updated resource in DB.

Postcondition: VNF instance in “INSTANTIATED” state, and healed.

4) Flow of Termination of a VNF instance

The procedure consists of the following steps as illustrated in above sequence:

1. Consumer sends a POST request to the “Terminate VNF Instance” resource.

2. OpenstackDriver will delete the stack using Heat.

3. The image created during instantiation will be deleted.

Postcondition: “instantiationState” should be set to “NOT_INSTANTIATED”.

5) Flow of deletion of a VNF instance resource

Precondition: VNF instance in NOT_INSTANTIATED state.

The procedure consists of the following steps as illustrated in above sequence:

1. Consumer sends a DELETE request to the “Individual VNF Instance” resource.

2. The VNFM deletes the VNF instance resource and the associated VNF instance identifier.

3. The VNFM returns a “204 No Content” response with an empty payload body.

Postcondition: VNF instance resource removed.

Error handling: If the “Individual VNF instance” resource is not in

NOT_INSTANTIATED state, the VNFM rejects the deletion request.

Support subset of SOL001 VNFD TOSCA service template

We are planning to provide limited support of VNFD TOSCA service template defined in NFV-SOL001

Supported Data Types

1. tosca.datatypes.nfv.ConnectivityType

2. tosca.datatypes.nfv.VirtualMemory

3. tosca.datatypes.nfv.VirtualCpu

4. tosca.datatypes.nfv.VduProfile

5. tosca.datatypes.nfv.VlProfile

6. tosca.datatypes.nfv.InstantiationLevel

7. tosca.datatypes.nfv.VduLevel

8. tosca.datatypes.nfv.ScaleInfo

9. tosca.datatypes.nfv.ScalingAspect

10. tosca.datatypes.nfv.LinkBitrateRequirements

11. tosca.datatypes.nfv.VnfAdditionalConfigurableProperties

12. tosca.datatypes.nfv.SwImageData

13. tosca.datatypes.nfv.VirtualBlockStorageData

14. tosca.datatypes.nfv.VirtualLinkBitrateLevel

15. tosca.datatypes.nfv.ChecksumData

Supported Artifact Types

1. tosca.artifacts.nfv.SwImage

Supported Capability Types

1. tosca.capabilities.nfv.VirtualBindable

2. tosca.capabilities.nfv.VirtualLinkable

3. tosca.capabilities.nfv.VirtualCompute

4. tosca.capabilities.nfv.VirtualStorage

Supported Interface Types

1. tosca.interfaces.nfv.Vnflcm

Supported Node Types

1. tosca.nodes.nfv.VNF

2. tosca.nodes.nfv.Vdu.Compute

3. tosca.nodes.nfv.Vdu.VirtualBlockStorage

4. tosca.nodes.nfv.VduCp

5. tosca.nodes.nfv.VnfVirtualLink

Supported Policy Types

1. tosca.policies.nfv.InstantiationLevels

2. tosca.policies.nfv.VduInstantiationLevels

3. tosca.policies.nfv.VirtualLinkInstantiationLevels

4. tosca.policies.nfv.ScalingAspects

5. tosca.policies.nfv.VduScalingAspectsDeltas

6. tosca.policies.nfv.VduInitialDelta

Add task_state to perform atomic operation on vnf instances

Add task_state to the vnf_instances db table. The main purpose of introducing task_state is to allow actions to be performed on VNF in atomic way. Meaning, if you are instantiating a VNF, it won’t allow you to perform same action or any other action on the VNF until that operation is complete. If user attempts to instantiate it again before completing the previous request, it will reject that request with 400 error.

Types of task_state:

• INSTANTIATING: Set when a user calls instantiate API. After the VNF is instantiated completely, it will be set to None. If it fails to instantiate a VNF successfully, then it will be set to ERROR.

• HEALING: Set when a user calls heal API. After the VNF is healed completely, it will be set to None. If it fails to heal a VNF successfully, then it will be set to ERROR.

• TERMINATING: Set when a user calls terminate API. After the VNF is terminated completely, it will be set to None. If it fails to terminate a VNF successfully, then it will be set to ERROR.

• ERROR: An user won’t be able to perform any actions on a VNF whose task_state is ERROR. An Operator will need to fix all such issues manually. We plan to fix VNFs in such states using periodic tasks in future.

Alternatives

None

Data model impact

Add below new tables in ‘tacker’ database. The corresponding schemas are detailed below:-

vnf_instances::

id uuid

vnfd_id uuid

vnf_instance_name varchar(255) NULL

vnf_instance_description varchar(1024) NULL

vnf_provider varchar(255) NOT NULL

vnf_product_name varchar(255) NOT NULL

vnf_software_version varchar(255) NOT NULL

vnfd_version varchar(255) NOT NULL

instantiation_state varchar(255) NOT NULL

task_state varchar(255) NULL

vim_connection_info json NULL

tenant_id varchar(64) NOT NULL

created_at datetime NOT NULL

updated_at datetime NULL

deleted_at datetime NULL

deleted tinyint(1) NULL

This table will have id as primary key. vnfd_id will be foreign key of vnf_package_vnfd.`vnfd_id`.

vnf_instantiated_info::

id int(11)

vnf_instance_id uuid

flavour_id varchar(255) NOT NULL

ext_cp_info json NOT NULL

ext_virtual_link_info json NULL

ext_managed_virtual_link_info json NULL

vnfc_resource_info json NULL

vnf_virtual_link_resource_info json NULL

virtual_storage_resource_info json NULL

vnf_state varchar(255) NOT NULL

instance_id varchar(255) NOT NULL

instantiation_level_id varchar(255) NULL

additional_params json NULL

created_at datetime NOT NULL

updated_at datetime NULL

deleted_at datetime NULL

deleted tinyint(1) NULL

This table will have id as primary key. vnf_instance_id will be foreign key of vnf_instances.`id`. flavour_Id will be foreign key of vnf_deployment_flavours.`flavour_id`.

vnf_resources::

id uuid

vnf_instance_id uuid

resource_name varchar(255) NULL

resource_type Integer NOT NULL

resource_identifier text NOT NULL

resource_status text NOT NULL

created_at datetime NOT NULL

updated_at datetime NULL

deleted_at datetime NULL

deleted tinyint(1) NULL

This table will have id as primary key. vnf_instance_Id will be foreign key of vnf_instances.`id`.

Note

The json data types for columns vim_connection_info, ext_cp_info, ext_virtual_link_info, ext_managed_virtual_link_info, vnfc_resource_info, vnf_virtual_link_resource_info, virtual_storage_resource_info will contain json data. While saving the data in DB, The version object will be serialized and stored as json and during retrieving it from DB, The json data will be deserialized to create the version object.

REST API impact

The following restFul APIs will be added:

• Name: Create VNF Identifier

  Description: Creates a new VNF instance resource

  Method type: POST

  URL for the resource: /vnflcm/v1/vnf_instances

  Request:

  Data type	Cardinality		Description
  CreateVnfRequest	1		The VNF creation parameters.

  Attribute name	Data type	Cardinality	Supported in (U)
  vnfdId	Identifier	1	Yes
  vnfInstanceName	String	0..1	Yes
  vnfInstanceDescription	String	0..1	Yes
  metadata	KeyValuePairs	0..1	No

  Response:

  Data type	Cardinality	Response Codes	Description
  VnfInstance	1	Success 201 Error 400 401 403	A VNF Instance identifier was created successfully.

• Name: Query VNF

  Description: Request to existing VNF instance resource by its id

  Method type: GET

  URL for the resource: /vnflcm/v1/vnf_instances/{vnfInstanceId}

  Resource URI variables for this resource:

  Name	Description
  vnfInstanceId	Identifier of the VNF instance.

  Response:

  Data type	Cardinality	Response Codes	Description
  VnfInstance	1	Success: 200 Error: 401, 403 404	Information about an individual VNF instance was queried successfully.

• Name: List VNF Instances

  Description: Request to list all existing VNF instances

  Method type: GET

  URL for the resource: /vnflcm/v1/vnf_instances

  Response:

  Data type	Cardinality	Response Codes	Description
  VnfInstance	0..N	Success: 200 Error: 401, 403	Information about zero or more VNF instances was queried successfully.

  Attribute name	Data type	Cardinality	Supported in (U)
  id	Identifier	1	Yes
  vnfInstanceName	String	0..1	Yes
  vnfInstanceDescription	String	0..1	Yes
  vnfdId	Identifier	1	Yes
  vnfProvider	String	1	Yes
  vnfProductName	String	1	Yes
  vnfSoftwareVersion	Version	1	Yes
  vnfdVersion	Version	1	Yes
  vnfConfigurableProperties	KeyValuePairs	0..1	No
  vimConnectionInfo	VimConnectionInfo	0..N -> 0..1	Yes
  instantiationState	Enum	1	Yes
  instantiatedVnfInfo	Structure	0..1	Yes
  >flavourId	IdentifierInVnfd	1	Yes
  >vnfState	VnfOperationalStateType	1	Yes
  >scaleStatus	ScaleInfo	0..N	No
  >extCpInfo	VnfExtCpInfo	1..N	Yes
  >extVirtualLinkInfo	ExtVirtualLinkInfo	0..N	Yes
  >extManagedVirtualLinkInfo	ExtManagedVirtualLinkInfo	0..N	Yes
  >monitoringParameters	MonitoringParameter	0..N	No
  >localizationLanguage	String	0..1	No
  >vnfcResourceInfo	VnfcResourceInfo	0..N	Yes
  >vnfVirtualLinkResourceInfo	VnfVirtualLinkResourceInfo	0..N	Yes
  >virtualStorageResourceInfo	VirtualStorageResourceInfo	0..N	Yes
  metadata	KeyValuePairs	0..1	No
  extensions	KeyValuePairs	0..1	No
  _links	Structure	1	Yes
  >self	Link	1	Yes
  >indicators	Link	0..1	No
  >instantiate	Link	0..1	Yes
  >terminate	Link	0..1	Yes
  >scale	Link	0..1	No
  >scaleToLevel	Link	0..1	No
  >changeFlavour	Link	0..1	No
  >heal	Link	0..1	Yes
  >operate	Link	0..1	No
  >changeExtConn	Link	0..1	No

• Name: Delete VNF Instance

  Description: Request to delete VNF instance resource by its id

  Method type: DELETE

  URL for the resource: /vnflcm/v1/vnf_instances/{vnfInstanceId}

  Resource URI variables for this resource:

  Name	Description
  vnfInstanceId	Identifier of the VNF instance.

  Response:

  Data type	Cardinality	Response Codes	Description
  n/a		Success: 204 Error: 401, 403 404	The VNF instance resource and the associated VNF identifier were deleted successfully.

• Name: Instantiate VNF task

  Description: This task resource represents the “Instantiate VNF” operation. The client can use this resource to instantiate a VNF instance.

  Method type: POST

  URL for the resource: /vnflcm/v1/vnf_instances/{vnfInstanceId}/instantiate

  Resource URI variables for this resource:

  Name	Definition
  vnfInstanceId	The identifier of the VNF instance to be instantiated.

  Request:

  Data type	Cardinality | Description
  InstantiateVnfRequest	1 | Parameters passed to instantiate task.

  Attribute name	Data type	Cardinality	Supported in (U)	Description
  flavourId	IdentifierInVnfd	1	Yes	Identifier of the VNF deployment flavour to be instantiated.
  instantiationLevelId	IdentifierInVnfd	0..1	Yes	Identifier of the instantiation level of the deployment flavour to be instantiated. If not present, the default instantiation level as declared in the VNFD is instantiated.
  extVirtualLinks	ExtVirtualLinkData	0..N	Yes	Information about external VLs to connect the VNF to.
  vimConnectionInfo	VimConnectionInfo	0..N -> 0..1	Yes	Information about VIM connections to be used for managing the resources for the VNF instance. In U release, only 0..1 VIMConnectionInfo will be accepted.
  additionalParams	KeyValuePairs	0..1	Yes	Additional input parameters for the instantiation process, specific to the VNF being instantiated.
  extManagedVirtualLinks	ExtManagedVirtualLinkData	0..N	Yes
  localizationLanguage	String	0..1	No
  extensions	KeyValuePairs	0..1	No

  Response:

  Data type	Cardinality	Response Codes	Description
  n/a		Success: 202 Error: 400, 401 403, 404, 409	The request was accepted for processing, but the processing has not been completed.

• Name: Heal VNF task

  Description: Request for healing a VNF instance

  Method type: POST

  URL for the resource: /vnflcm/v1/vnf_instances/{vnfInstanceId}/heal

  Resource URI variables for this resource:

  Name	Description
  vnfInstanceId	The identifier of the VNF instance to be healed.

  Request:

  Data type	Cardinality	Description
  HealVnfRequest	1	Parameters for the Heal VNF operation.

  Attribute name	Data type	Cardinality	Supported in (U)	Description
  vnfcInstanceId	Identifier	0..N	Yes
  cause	String	0..1	Yes
  additionalParams	KeyValuePairs	0..1	No

  Response:

  Data type	Cardinality	Response Codes	Description
  n/a	n/a	Success: 202 Error: 401, 403 404, 409	The request was accepted for processing, but the processing has not been completed.

• Name: Terminate VNF task

  Description: This task resource represents the “Terminate VNF” operation. The client can use this resource to terminate a VNF instance.

  Method type: POST

  URL for the resource: /vnflcm/v1/vnf_instances/{vnfInstanceId}/terminate

  Resource URI variables for this resource:

  Name	Description
  vnfInstanceId	The identifier of the VNF instance to be terminated.

  Request:

  Data type	Cardinality | Description
  TerminateVnfRequest | 1 | Parameters passed to Terminate VNF task.

  Attribute name	Data type	Possible values	Cardinality	Support	Description
  terminationType	Enum (inlined)	FORCEFUL GRACEFUL	1	Yes	Indicates whether forceful or graceful termination is requested. FORCEFUL: The VNFM will shut down the VNF and release the resources immediately. GRACEFUL: The VNFM will first arrange to take the VNF out of service. Once the operation of taking the VNF out of service finishes, it will wait for the period as specified in the gracefulTerminationTimeout and then VNFM will shutdown the VNF and release the resources.
  additionalParams	KeyValuePairs		0..1	No	Additional parameters to the termination process, specific to the VNF being terminated.
  gracefulTerminationTimeout	Integer		0..1	Yes	This attribute is only applicable in case of graceful termination. It defines the time to wait for the VNF to be taken out of service before shutting down the VNF and releasing the resources. The unit is seconds.

  Response:

  Data type	Cardinality	Response Codes	Description
  n/a		Success: 202 Error: 400, 401 403, 404, 409	The request was accepted for processing, but the processing has not been completed.

• Future work

  1. Scale VNF task

  2. Operate VNF task

  3. VNF LCM operation occurrences

  4. Individual VNF LCM operation occurrence

Security impact

None

Notifications impact

None

Other end user impact

Add new OSC commands in python-tackerclient to invoke VNF lifecycle management of VNF instances APIs.

Name	Method	URI	CLI Openstack
List vnf instances	GET	/vnflcm/v1/vnf_instances	vnflcm list
Create vnf instance	POST	/vnflcm/v1/vnf_instances | vnflcm list	vnflcm create
Get vnf instance	GET	/vnflcm/v1/vnf_instances/{vnfInstanceID}	vnflcm show
Delete vnf instance	DELETE	/vnflcm/v1/vnf_instances/{vnfInstanceID}	vnflcm delete
Instantiate vnf task	POST	/vnflcm/v1/vnf_instances/{vnfInstanceID}/instantiate	vnflcm instantiate
Heal vnf task	POST	/vnflcm/v1/vnf_instances/{vnfInstanceID}/heal	vnflcm heal
Terminate vnf task	POST	/vnflcm/v1/vnf_instances/{vnfInstanceID}/terminate	vnflcm terminate

Performance Impact

None

Other deployer impact

The previously created VNFs will not be allowed to be managed using the newly introduced APIs.

Developer impact

None

Implementation

Assignee(s)

Primary assignee:

Keiko Kuriu <keiko.kuriu.wa@hco.ntt.co.jp>

Other contributors:

Hiroyuki Jo <hiroyuki.jo.mt@hco.ntt.co.jp>

Tushar Patil <tushar.vitthal.patil@gmail.com>

Nitin Uikey <nitin.uikey@nttdata.com>

Ajay Parja <Ajay.Parja@nttdata.com>

Shubham Potale <Shubham.Potale@nttdata.com>

Work Items

• Add new REST API endpoints to Tacker-server for VNF lifecycle management of VNF instances.

• Make changes in Heat-translator to translate new node types introduced in Tosca template version 1.2.

• Make changes in python-tackerclient to add new OSC commands for calling VNF lifecycle management of VNF instances restFul APIs.

• Add post processing to extract information regarding API request body.

• Add new unit and functional tests.

• Change API Tacker documentation.

Dependencies

None

Testing

Unit and functional test cases will be added for VNF lifecycle management of VNF instances.

Documentation Impact

Complete user guide will be added to explain how to invoke VNF lifecycle management of VNF instances with examples.

References

[1]

https://www.etsi.org/technologies-clusters/technologies/NFV

[2]

https://portal.etsi.org/Portals/0/TBpages/CTI/Docs/2nd_ETSI_NFV_Plugtests_Report_v1.0.0.pdf