path: root/docs/Chapter7.rst

**7. ONAP Management Requirements**
=====================================

a. Service Design
==================

This section, Service Design, has been left intentionally blank. It is out-of-scope for the VNF Requirements project for the Amsterdam release and no numbered requirements are expected. Content may be added in future updates of this document.

b. VNF On-boarding and package management
==========================================

**Design Definition**

The ONAP Design Time Framework provides the ability to design NFV
resources including VNFs, Services, and products. The vendor must
provide VNF packages that include a rich set of recipes, management and
functional interfaces, policies, configuration parameters, and
infrastructure requirements that can be utilized by the ONAP Design
module to onboard and catalog these resources. Initially this
information may be provided in documents, but in the near future a
method will be developed to automate as much of the transfer of data as
possible to satisfy its long term requirements.

The current VNF Package Requirement is based on a subset of the
Requirements contained in the ETSI Document: ETSI GS NFV-MAN 001 v1.1.1
and GS NFV IFA011 V0.3.0 (2015-10) - Network Functions Virtualization
(NFV), Management and Orchestration, VNF Packaging Specification.

**Resource Description**

* R-77707 The VNF Vendor **MUST** include a Manifest File that contains a list of all the components in the VNF package.
* R-66070 The VNF Package **MUST** include VNF Identification Data to uniquely identify the resource for a given Vendor. The identification data must include: an identifier for the VNF, the name of the VNF as was given by the VNF Vendor, VNF description, VNF Vendor, and version.
* R-69565 The VNF Package **MUST** include documentation describing VNF Management APIs. The document must include information and tools for:

 - ONAP to deploy and configure (initially and ongoing) the VNF application(s) (e.g., NETCONF APIs). Includes description of configurable parameters for the VNF and whether the parameters can be configured after VNF instantiation.
 - ONAP to monitor the health of the VNF (conditions that require healing and/or scaling responses). Includes a description of:

  - Parameters that can be monitored for the VNF and event records (status, fault, flow, session, call, control plane, etc.) generated by the VNF after instantiation.
  - Runtime lifecycle events and related actions (e.g., control responses, tests) which can be performed for the VNF.

* R-84366 The VNF Package **MUST** include documentation describing VNF Functional APIs that are utilized to build network and application services. This document describes the externally exposed functional inputs and outputs for the VNF, including interface format and protocols supported.
* R-36280 The VNF Vendor **MUST** provide documentation describing VNF Functional Capabilities that are utilized to operationalize the VNF and compose complex services.
* R-98617 The VNF Vendor **MUST** provide information regarding any dependency (e.g., affinity, anti-affinity) with other VNFs and resources.

**Resource Configuration**

* R-89571 The VNF **MUST** support and provide artifacts for configuration management using at least one of the following technologies:

 - Netconf/YANG
 - Chef
 - Ansible

 Note: The requirements for Netconf/YANG, Chef, and Ansible protocols are provided separately and must be supported only if the corresponding protocol option is provided by the vendor.

 **Configuration Management via Netconf/YANG**

 * R-30278 The VNF Vendor **MUST** provide a Resource/Device YANG model as a foundation for creating the YANG model for configuration. This will include VNF attributes/parameters and valid values/attributes configurable by policy.
 
 **Configuration Management via Chef** 

 * R-13390 The VNF Vendor **MUST** provide cookbooks to be loaded on the appropriate Chef Server.
 * R-18525 The VNF Vendor **MUST** provide a JSON file for each supported action for the VNF.  The JSON file must contain key value pairs with all relevant values populated with sample data that illustrates its usage. The fields and their description are defined in Appendix A.
 
 Note: Chef support in ONAP is not currently available and planned for 4Q 2017.

 **Configuration Management via Ansible**

 * R-75608 The VNF Vendor **MUST** provide playbooks to be loaded on the appropriate Ansible Server.
 * R-16777 The VNF Vendor **MUST** provide a JSON file for each supported action for the VNF.  The JSON file must contain key value pairs with all relevant values populated with sample data that illustrates its usage. The fields and their description are defined in Appendix B.
  
  Note: Ansible support in ONAP is not currently available and planned for 4Q 2017.

* R-46567 The VNF Package **MUST** include configuration scripts for boot sequence and configuration.
* R-16065 The VNF Vendor **MUST** provide configurable parameters (if unable to conform to YANG model) including VNF attributes/parameters and valid values, dynamic attributes and cross parameter dependencies (e.g., customer provisioning data).

**Resource Control Loop**

* R-22888 The VNF Vendor **MUST** provide documentation for the VNF Policy Description to manage the VNF runtime lifecycle. The document must include a description of how the policies (conditions and actions) are implemented in the VNF.
* R-01556 The VNF Package **MUST** include documentation describing the fault, performance, capacity events/alarms and other event records that are made available by the VNF. The document must include:

 - A unique identification string for the specific VNF, a description of the problem that caused the error, and steps or procedures to perform Root Cause Analysis and resolve the issue.
 - All events, severity level (e.g., informational, warning, error) and descriptions including causes/fixes if applicable for the event.
 - All events (fault, measurement for VNF Scaling, Syslogs, State Change and Mobile Flow), that need to be collected at each VM, VNFC (defined in *VNF Guidelines for Network Cloud and ONAP*) and for the overall VNF.

* R-27711 The VNF Vendor **MUST** provide an XML file that contains a list of VNF error codes, descriptions of the error, and possible causes/corrective action.
* R-01478 The VNF Package **MUST** include documentation describing all parameters that are available to monitor the VNF after instantiation (includes all counters, OIDs, PM data, KPIs, etc.) that must be collected for reporting purposes. The documentation must include a list of:

 - Monitoring parameters/counters exposed for virtual resource management and VNF application management.
 - KPIs and metrics that need to be collected at each VM for capacity planning and performance management purposes.
 - The monitoring parameters must include latencies, success rates, retry rates, load and quality (e.g., DPM) for the key transactions/functions supported by the VNF and those that must be exercised by the VNF in order to perform its function.
 - For each KPI, provide lower and upper limits.
 - When relevant, provide a threshold crossing alert point for each KPI and describe the significance of the threshold crossing.
 - For each KPI, identify the suggested actions that need to be performed when a threshold crossing alert event is recorded.
 - Describe any requirements for the monitoring component of tools for Network Cloud automation and management to provide these records to components of the VNF.
 - When applicable, provide calculators needed to convert raw data into appropriate reporting artifacts.

* R-56815 The VNF Package **MUST** include documentation describing supported VNF scaling capabilities and capacity limits (e.g., number of users, bandwidth, throughput, concurrent calls).
* R-48596 The VNF Package **MUST** include documentation describing the characteristics for the VNF reliability and high availability.
* R-74763 The VNF Vendor **MUST** provide an artifact per VNF that contains all of the VNF Event Records supported. The artifact should include reference to the specific release of the VNF Event Stream Common Event Data Model document it is based on. (e.g., `VES Event Listener <https://github.com/att/evel-test-collector/tree/master/docs/att_interface_definition>`__)

**Compute, Network, abd Storage Requirements**

* R-35851 The VNF Package **MUST** include VNF topology that describes basic network and application connectivity internal and external to the VNF including Link type, KPIs, Bandwidth, latency, jitter, QoS (if applicable) for each interface.
* R-97102 The VNF Package **MUST** include VM requirements via a Heat template that provides the necessary data for:

- VM specifications for all VNF components - for hypervisor, CPU, memory, storage.
  - Network connections, interface connections, internal and external to VNF.
  - High availability redundancy model.
  - Scaling/growth VM specifications.

  Note: Must comply with the *Heat requirements in 5.b*.

* R-26881 The VNF Vendor **MUST** provide the binaries and images needed to instantiate the VNF (VNF and VNFC images).
* R-96634 The VNF Vendor **MUST** describe scaling capabilities to manage scaling characteristics of the VNF.


**Testing**

* R-43958 The VNF Package **MUST** include documentation describing the tests that were conducted by the Vendor and the test results.
* R-04298 The VNF Vendor **MUST** provide their testing scripts to support testing.
* R-58775 The VNF Vendor **MUST** provide software components that can be packaged with/near the VNF, if needed, to simulate any functions or systems that connect to the VNF system under test. This component is necessary only if the existing testing environment does not have the necessary simulators.

**Licensing Requirements**

* R-85653 The VNF **MUST** provide metrics (e.g., number of sessions, number of subscribers, number of seats, etc.) to ONAP for tracking every license.
* R-44125 The VNF Vendor **MUST** agree to the process that can be met by Service Provider reporting infrastructure. The Contract shall define the reporting process and the available reporting tools.
* R-40827 The VNF Vendor **MUST** enumerate all of the open source licenses their VNF(s) incorporate.
* R-97293 The VNF Vendor **MUST NOT** require audits of Service Provider’s business.
* R-44569 The VNF Vendor **MUST NOT** require additional infrastructure such as a vendor license server for Vendor functions and metrics..
* R-13613 The VNF **MUST** provide clear measurements for licensing purposes to allow automated scale up/down by the management system.
* R-27511 The VNF Vendor **MUST** provide the ability to scale up a vendor supplied product during growth and scale down a vendor supplied product during decline without “real-time” restrictions based upon vendor permissions.
* R-85991 The VNF Vendor **MUST** provide a universal license key per VNF to be used as needed by services (i.e., not tied to a VM instance) as the recommended solution. The vendor may provide pools of Unique VNF License Keys, where there is a unique key for each VNF instance as an alternate solution. Licensing issues should be resolved without interrupting in-service VNFs.
* R-47849 The VNF Vendor **MUST** support the metadata about licenses (and their applicable entitlements) as defined in this document for VNF software, and any license keys required to authorize use of the VNF software.  This metadata will be used to facilitate onboarding the VNF into the ONAP environment and automating processes for putting the licenses into use and managing the full lifecycle of the licenses. The details of this license model are described in Appendix C. Note: License metadata support in ONAP is not currently available and planned for 1Q 2018.

c. Configuration Management
===========================

ONAP interacts directly with VNFs through its Network and Application
Adapters to perform configuration activities within NFV environment.
These activities include service and resource
configuration/reconfiguration, automated scaling of resources, service
and resource removal to support runtime lifecycle management of VNFs and
services. The Adapters employ a model driven approach along with
standardized APIs provided by the VNF developers to configure resources
and manage their runtime lifecycle.

Additional details can be found in the `ONAP Application Controller (APPC) API Guide <http://onap.readthedocs.io/en/latest/submodules/appc.git/docs/APPC%20API%20Guide/APPC%20API%20Guide.html>`_.

NETCONF Standards and Capabilities
----------------------------------

ONAP Controllers and their Adapters utilize device YANG model and
NETCONF APIs to make the required changes in the VNF state and
configuration. The VNF providers must provide the Device YANG model and
NETCONF server supporting NETCONF APIs to comply with target ONAP and
industry standards.

**VNF Configuration via NETCONF Requirements**

**Configuration Management**

* R-88026 The VNF **MUST** include a NETCONF server enabling runtime configuration and lifecycle management capabilities. 
* R-95950 The VNF **MUST** provide a NETCONF interface fully defined by supplied YANG models for the embedded NETCONF server. 

**NETCONF Server Requirements**

* R-73468 The VNF **MUST** allow the NETCONF server connection parameters to be configurable during virtual machine instantiation through Heat templates where SSH keys, usernames, passwords, SSH service and SSH port numbers are Heat template parameters.
* R-90007 The VNF **MUST** implement the protocol operation: **close-session()**- Gracefully close the current session.
* R-70496 The VNF **MUST** implement the protocol operation: **commit(confirmed, confirm-timeout)** - Commit candidate configuration datastore to the running configuration.
* R-18733 The VNF **MUST** implement the protocol operation: **discard-changes()** - Revert the candidate configuration datastore to the running configuration.
* R-44281 The VNF **MUST** implement the protocol operation: **edit-config(target, default-operation, test-option, error-option, config)** - Edit the target configuration datastore by merging, replacing, creating, or deleting new config elements.
* R-60106 The VNF **MUST** implement the protocol operation: **get(filter)** - Retrieve (a filtered subset of) the running configuration and device state information. This should include the list of VNF supported schemas.
* R-29488 The VNF **MUST** implement the protocol operation: **get-config(source, filter)** - Retrieve a (filtered subset of a) configuration from the configuration datastore source.
* R-11235 The VNF **MUST** implement the protocol operation: **kill-session(session)** - Force the termination of **session**.
* R-02597 The VNF **MUST** implement the protocol operation: **lock(target)** - Lock the configuration datastore target.
* R-96554 The VNF **MUST** implement the protocol operation: **unlock(target)** - Unlock the configuration datastore target.
* R-29324 The VNF **SHOULD** implement the protocol operation: **copy-config(target, source) -** Copy the content of the configuration datastore source to the configuration datastore target. 
* R-88031 The VNF **SHOULD** implement the protocol operation: **delete-config(target) -** Delete the named configuration datastore target.
* R-97529 The VNF **SHOULD** implement the protocol operation: **get-schema(identifier, version, format) -** Retrieve the YANG schema.
* R-62468 The VNF **MUST** allow all configuration data shall to be edited through a NETCONF <edit-config> operation. Proprietary NETCONF RPCs that make configuration changes are not sufficient.
* R-01382 The VNF **MUST** allow the entire configuration of the VNF to be retrieved via NETCONF's <get-config> and <edit-config>, independently of whether it was configured via NETCONF or other mechanisms.
* R-28756 The VNF **MUST** support **:partial-lock** and **:partial-unlock** capabilities, defined in RFC 5717. This allows multiple independent clients to each write to a different part of the <running> configuration at the same time.
* R-83873 The VNF **MUST** support **:rollback-on-error** value for the <error-option> parameter to the <edit-config> operation. If any error occurs during the requested edit operation, then the target database (usually the running configuration) will be left affected. This provides an 'all-or-nothing' edit mode for a single <edit-config> request.
* R-68990 The VNF **MUST** support the **:startup** capability. It will allow the running configuration to be copied to this special database. It can also be locked and unlocked.
* R-68200 The VNF **MUST** support the **:url** value to specify protocol operation source and target parameters. The capability URI for this feature will indicate which schemes (e.g., file, https, sftp) that the server supports within a particular URL value. The 'file' scheme allows for editable local configuration databases. The other schemes allow for remote storage of configuration databases.
* R-20353 The VNF **MUST** implement at least one of the capabilities **:candidate** or **:writable-running**. If both **:candidate** and **:writable-running** are provided then two locks should be supported.
* R-11499 The VNF **MUST** fully support the XPath 1.0 specification for filtered retrieval of configuration and other database contents. The 'type' attribute within the <filter> parameter for <get> and <get-config> operations may be set to 'xpath'. The 'select' attribute (which contains the XPath expression) will also be supported by the server. A server may support partial XPath retrieval filtering, but it cannot advertise the **:xpath** capability unless the entire XPath 1.0 specification is supported.
* R-83790 The VNF **MUST** implement the **:validate** capability
* R-49145 The VNF **MUST** implement **:confirmed-commit** If **:candidate** is supported.
* R-58358 The VNF **MUST** implement the **:with-defaults** capability [RFC6243].
* R-59610 The VNF **MUST** implement the data model discovery and download as defined in [RFC6022].
* R-87662 The VNF **SHOULD** implement the NETCONF Event Notifications [RFC5277].
* R-93443 The VNF **MUST** define all data models in YANG [RFC6020], and the mapping to NETCONF shall follow the rules defined in this RFC.
* R-26115 The VNF **MUST** follow the data model upgrade rules defined in [RFC6020] section 10. All deviations from section 10 rules shall be handled by a built-in automatic upgrade mechanism.
* R-10716 The VNF **MUST** support parallel and simultaneous configuration of separate objects within itself.
* R-29495 The VNF **MUST** support locking if a common object is being manipulated by two simultaneous NETCONF configuration operations on the same VNF within the context of the same writable running data store (e.g., if an interface parameter is being configured then it should be locked out for configuration by a simultaneous configuration operation on that same interface parameter).
* R-53015 The VNF **MUST** apply locking based on the sequence of NETCONF operations, with the first configuration operation locking out all others until completed.
* R-02616 The VNF **MUST** permit locking at the finest granularity if a VNF needs to lock an object for configuration to avoid blocking simultaneous configuration operations on unrelated objects (e.g., BGP configuration should not be locked out if an interface is being configured or entire Interface configuration should not be locked out if a non-overlapping parameter on the interface is being configured).
* R-41829 The VNF **MUST** be able to specify the granularity of the lock via a restricted or full XPath expression.
* R-66793 The VNF **MUST** guarantee the VNF configuration integrity for all simultaneous configuration operations (e.g., if a change is attempted to the BUM filter rate from multiple interfaces on the same EVC, then they need to be sequenced in the VNF without locking either configuration method out).
* R-54190 The VNF **MUST** release locks to prevent permanent lock-outs when/if a session applying the lock is terminated (e.g., SSH session is terminated).
* R-03465 The VNF **MUST** release locks to prevent permanent lock-outs when the corresponding <partial-unlock> operation succeeds.
* R-63935 The VNF **MUST** release locks to prevent permanent lock-outs when a user configured timer has expired forcing the NETCONF SSH Session termination (i.e., product must expose a configuration knob for a user setting of a lock expiration timer)
* R-10173 The VNF **MUST** allow another NETCONF session to be able to initiate the release of the lock by killing the session owning the lock, using the <kill-session> operation to guard against hung NETCONF sessions.
* R-88899 The VNF **MUST** support simultaneous <commit> operations within the context of this locking requirements framework.
* R-07545 The VNF **MUST** support all operations, administration and management (OAM) functions available from the supplier for VNFs using the supplied YANG code and associated NETCONF servers.
* R-60656 The VNF **MUST** support sub tree filtering.
* R-80898 The VNF **MUST** support heartbeat via a <get> with null filter.
* R-06617 The VNF **MUST** support get-schema (ietf-netconf-monitoring) to pull YANG model over session.
* R-25238 The VNF PACKAGE **MUST** validated YANG code using the open source pyang [2]_ program using the following commands:

.. code-block:: python

 $ pyang --verbose --strict <YANG-file-name(s)>
 $ echo $!

* R-63953 The VNF **MUST** have the echo command return a zero value otherwise the validation has failed
* R-26508 The VNF **MUST** support NETCONF server that can be mounted on OpenDaylight (client) and perform the following operations:
 
- Modify, update, change, rollback configurations using each configuration data element.
- Query each state (non-configuration) data element. 
- Execute each YANG RPC.
- Receive data through each notification statement.



The following requirements provides the Yang models that suppliers must
conform, and those where applicable, that suppliers need to use.

* R-28545 The VNF **MUST** conform its YANG model to RFC 6060, “YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)”
* R-29967 The VNF **MUST** conform its YANG model to RFC 6022, “YANG module for NETCONF monitoring”.
* R-22700 The VNF **MUST** conform its YANG model to RFC 6470, “NETCONF Base Notifications”.
* R-10353 The VNF **MUST** conform its YANG model to RFC 6244, “An Architecture for Network Management Using NETCONF and YANG”.
* R-53317 The VNF **MUST** conform its YANG model to RFC 6087, “Guidelines for Authors and Reviewers of YANG Data Model Documents”.
* R-33955 The VNF **SHOULD** conform its YANG model to \*\*RFC 6991, “Common YANG Data Types”.
* R-22946 The VNF **SHOULD** conform its YANG model to RFC 6536, “NETCONF Access Control Model”.
* R-10129 The VNF **SHOULD** conform its YANG model to RFC 7223, “A YANG Data Model for Interface Management”.
* R-12271 The VNF **SHOULD** conform its YANG model to RFC 7223, “IANA Interface Type YANG Module”.
* R-49036 The VNF **SHOULD** conform its YANG model to RFC 7277, “A YANG Data Model for IP Management”.
* R-87564 The VNF **SHOULD** conform its YANG model to RFC 7317, “A YANG Data Model for System Management”.
* R-24269 The VNF **SHOULD** conform its YANG model to RFC 7407, “A YANG Data Model for SNMP Configuration”.

The NETCONF server interface shall fully conform to the following
NETCONF RFCs.

* R-33946 The VNF **MUST** conform to the NETCONF RFC 4741, “NETCONF Configuration Protocol”.
* R-04158 The VNF **MUST** conform to the NETCONF RFC 4742, “Using the NETCONF Configuration Protocol over Secure Shell (SSH)”.
* R-13800 The VNF **MUST** conform to the NETCONF RFC 5277, “NETCONF Event Notification”.
* R-01334 The VNF **MUST** conform to the NETCONF RFC 5717, “Partial Lock Remote Procedure Call”.
* R-08134 The VNF **MUST** conform to the NETCONF RFC 6241, “NETCONF Configuration Protocol”.
* R-78282 The VNF **MUST** conform to the NETCONF RFC 6242, “Using the Network Configuration Protocol over Secure Shell”.

VNF REST APIs 
--------------

Healthcheck is a command for which no NETCONF support exists. Therefore,
this must be supported using a RESTful interface which we have defined.

The VNF via APP-C must provide a REST formatted GET RPCs to support Healthcheck
queries via the GET method over HTTP(s).

The VNF via VF-C must provide REST APIs to make the configurations of
associated VNFs.

The port number, url, and other authentication information is provided
by the VNF vendor.

**REST APIs**

* R-31809 The VNF **MUST** support the HealthCheck RPC. The HealthCheck RPC, executes a vendor-defined VNF Healthcheck over the scope of the entire VNF (e.g., if there are multiple VNFCs, then run a health check, as appropriate, for all VNFCs). It returns a 200 OK if the test completes. A JSON object is returned indicating state (healthy, unhealthy), scope identifier, time-stamp and one or more blocks containing info and fault information. If the VNF is unable to run the HealthCheck, return a standard http error code and message.

Examples:

.. code-block:: python

 200
 { 
   "identifier": "scope represented",
   "state": "healthy",
   "time": "01-01-1000:0000"
 } 

 200
 { 
   "identifier": "scope represented",
   "state": "unhealthy",
    {[
   "info": "System threshold exceeded details", 
   "fault":
     { 
       "cpuOverall": 0.80,
       "cpuThreshold": 0.45    
     }
     ]},    
   "time": "01-01-1000:0000"
 }


**Table 5. VNF REST APIs**

+-----------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+------------+------------+
| **Principal**   | **Description**                                                                                                                                                                                                                                                                                                                                                                                       | **Type**   | **ID #**   |
+=================+=======================================================================================================================================================================================================================================================================================================================================================================================================+============+============+
+-----------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+------------+------------+
| REST APIs       |  **/configuration** This API executes a vendor-defined VNF configuration action over the scope of the entire VNF(e.g if there are multiple VMs, then run configuration on all VMs according to the input parameters).                                                                                                                                                                                 |  Must      | 12200      |
|                 |  **/configuration** returns a 201 Created if the configuration succeeds or a 4XX/5XX response if it fails. A JSON object is returned indicating the outcome of the VNF configuration including all the necessary configuration info.                                                                                                                                                                  |            |            |
+-----------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+------------+------------+

Chef Standards and Capabilities
-------------------------------

ONAP will support configuration of VNFs via Chef subject to the
requirements and guidelines defined in this section.

The Chef configuration management mechanism follows a client-server
model. It requires the presence of a Chef-Client on the VNF that will be
directly managed by a Chef Server. The Chef-client will register with
the appropriate Chef Server and are managed via ‘cookbooks’ and
configuration attributes loaded on the Chef Server which contain all
necessary information to execute the appropriate actions on the VNF via
the Chef-client.

ONAP will utilize the open source Chef Server, invoke the documented
Chef REST APIs to manage the VNF and requires the use of open source
Chef-Client and Push Jobs Client on the VNF
(https://downloads.chef.io/).

**VNF Configuration via Chef Requirements**

**Chef Server Requirements**

ONAP will interact with the Chef Server designated to manage a target VNF. ONAP design allows for the VNF to register with the following types of Chef Server  [3]_:

-  **Chef Server hosted by ONAP**: ONAP will provide a Chef Server to manage a VNF.

 * R-77786 The VNF Package **MUST** include all relevant cookbooks to be loaded on the ONAP Chef Server.

-  **Chef Server hosted in Tenant Space**: The Chef Server may also be hosted external to ONAP in tenant space.

 * R-85428 The VNF **MUST** meet the same guidelines as Chef Server hosted by ONAP.
 * R-23823 The VNF Package **MUST** include appropriate credentials so that ONAP can interact with the Chef Server.

**Chef Client Requirements**

* R-79224 The VNF **MUST** have the chef-client be preloaded with validator keys and configuration to register with the designated Chef Server as part of the installation process.
* R-72184 The VNF **MUST** have routable FQDNs for all the endpoints (VMs) of a VNF that contain chef-clients which are used to register with the Chef Server.  As part of invoking VNF actions, ONAP will trigger push jobs against FQDNs of endpoints for a VNF, if required.
* R-47068 The VNF **MAY** expose a single endpoint that is responsible for all functionality.
* R-67114 The VNF **MUST** be installed with:

 -  Chef-Client >= 12.0
 -  Chef push jobs client >= 2.0

**Chef Roles/Requirements**

* R-27310 The VNF Package **MUST** include all relevant Chef artifacts (roles/cookbooks/recipes) required to execute VNF actions requested by ONAP for loading on appropriate Chef Server.
* R-26567 The VNF Package **MUST** include a run list of roles/cookbooks/recipes, for each supported VNF action, that will perform the desired VNF action in its entirety as specified by ONAP (see Section 8.c, ONAP Controller APIs and Behavior, for list of VNF actions and requirements), when triggered by a chef-client run list in JSON file.
* R-98911 The VNF **MUST NOT** use any instance specific parameters for the VNF in roles/cookbooks/recipes invoked for a VNF action.
* R-37929 The VNF **MUST** accept all necessary instance specific data from the environment or node object attributes for the VNF in roles/cookbooks/recipes invoked for a VNF action.
* R-62170 The VNF **MUST** over-ride any default values for configurable parameters that can be set by ONAP in the roles, cookbooks and recipes.
* R-78116 The VNF **MUST** update status on the Chef Server appropriately (e.g., via a fail or raise an exception) if the chef-client run encounters any critical errors/failures when executing a VNF action.
* R-44013 The VNF **MUST** populate an attribute, defined as node[‘PushJobOutput’] with the desired output on all nodes in the push job that execute chef-client run if the VNF action requires the output of a chef-client run be made available (e.g., get running configuration).
* R-30654 The VNF Package **MUST** have appropriate cookbooks that are designed to automatically ‘rollback’ to the original state in case of any errors for actions that change state of the VNF (e.g., configure).
* R-65755 The VNF **SHOULD** support callback URLs to return information to ONAP upon completion of the chef-client run for any chef-client run associated with a VNF action.

-  As part of the push job, ONAP will provide two parameters in the environment of the push job JSON object:
    -  ‘RequestId’ a unique Id to be used to identify the request,
    -  ‘CallbackUrl’, the URL to post response back.

-  If the CallbackUrl field is empty or missing in the push job, then the chef-client run need not post the results back via callback.

* R-15885 The VNF **MUST** Upon completion of the chef-client run, POST back on the callback URL, a JSON object as described in Table A2 if the chef-client run list includes a cookbook/recipe that is callback capable. Failure to POST on the Callback Url should not be considered a critical error. That is, if the chef-client successfully completes the VNF action, it should reflect this status on the Chef Server regardless of whether the Callback succeeded or not.

ONAP Chef API Usage
~~~~~~~~~~~~~~~~~~~

This section outlines the workflow that ONAP invokes when it receives an
action request against a Chef managed VNF.

1. When ONAP receives a request for an action for a Chef Managed VNF, it
   retrieves the corresponding template (based on **action** and
   **VNF)** from its database and sets necessary values in the
   “Environment”, “Node” and “NodeList” keys (if present) from either
   the payload of the received action or internal data.

2. If “Environment” key is present in the updated template, it posts the
   corresponding JSON dictionary to the appropriate Environment object
   REST endpoint on the Chef Server thus updating the Environment
   attributes on the Chef Server.

3. Next, it creates a Node Object from the “Node” JSON dictionary for
   all elements listed in the NodeList (using the FQDN to construct the
   endpoint) by replicating it  [4]_. As part of this process, it will
   set the name field in each Node Object to the corresponding FQDN.
   These node objects are then posted on the Chef Server to
   corresponding Node Object REST endpoints to update the corresponding
   node attributes.

4. If PushJobFlag is set to “True” in the template, ONAP requests a push
   job against all the nodes in the NodeList to trigger
   chef-client\ **.** It will not invoke any other command via the push
   job. ONAP will include a callback URL in the push job request and a
   unique Request Id. An example push job posted by ONAP is listed
   below:

   {

   "command": "chef-client",

   "run\_timeout": 300,

   "nodes”: [“node1.vnf\_a.onap.com”, “node2.vnf\_a.onap.com”],

   "env": {

   “RequestId”:”8279-abcd-aksdj-19231”,

   “CallbackUrl”:”<callback>”

   },

   }

5. If CallbackCapable field in the template is not present or set to
   “False” ONAP will poll the Chef Server to check completion status of
   the push job.

6. If “GetOutputFlag” is set to “True” in the template and
   CallbackCapable is not set to “True”, ONAP will retrieve any output
   from each node where the push job has finished by accessing the Node
   Object attribute node[‘PushJobOutput’].

Ansible Standards and Capabilities
----------------------------------

ONAP will support configuration of VNFs via Ansible subject to the
requirements and guidelines defined in this section.

Ansible allows agentless management of VMs via execution of ‘playbooks’
over ssh. The ‘playbooks’ are a structured set of tasks which contain
all the necessary data and execution capabilities to take the necessary
action on one or more target VMs of the VNF. ONAP will utilize the
framework of an Ansible Server that will host and invoke playbooks to
manage VNFs that support Ansible.

**VNF Configuration via Ansible Requirements**

**Ansible Server Requirements**

ONAP will utilize an Ansible server in order to manage VNFs that support Ansible playbooks.  We note that Ansible in general does not require the use of a server. However, this framework has been adopted to align with ONAP architecture, ease of management and scalability.
All playbooks for the VNF will be hosted on a designated Ansible Server that meets ONAP Ansible API requirements. ONAP design allows for VNFs to be managed by an Ansible Server in any of the two following forms [5]_:

-  **Ansible Server hosted by ONAP**: ONAP will provide an Ansible Server to manage a VNF.

 * R-07879 The VNF Package **MUST** include all relevant playbooks to ONAP to be loaded on the Ansible Server.

-  **Ansible Server hosted in Tenant Space**:

 * R-35305 The VNF **MUST** meet the same guidelines as the Ansible Server hosted by ONAP.
 * R-91681 The VNF **MUST** meet the ONAP Ansible Server API Interface requirements.

**Ansible Client Requirements**

* R-32217 The VNF **MUST** have routable FQDNs that are reachable via the Ansible Server for the endpoints (VMs) of a VNF on which playbooks will be executed. ONAP will initiate requests to the Ansible Server for invocation of playbooks against these end points [6]_.
* R-98929 The VNF **MAY** have a single endpoint.
* R-54373 The VNF **MUST** have Python >= 2.7 on the endpoint VM(s) of a VNF on which an Ansible playbook will be executed.
* R-35401 The VNF **MUST** must support SSH and allow SSH access to the Ansible server for the endpoint VM(s) and comply with the  Network Cloud Service Provider guidelines for authentication and access.

**Ansible Playbook Requirements**

An Ansible playbook is a collection of tasks that is executed on the Ansible server (local host) and/or the target VM (s) in order to complete the desired action.

* R-40293 The VNF **MUST** make available (or load on VNF Ansible Server) playbooks that conform to the ONAP requirement.
* R-49396 The VNF **MUST** support each VNF action by invocation of **one** playbook [7]_. The playbook will be responsible for executing all necessary tasks (as well as calling other playbooks) to complete the request.
* R-33280 The VNF **MUST NOT** use any instance specific parameters in a playbook.
* R-48698 The VNF **MUST** utilize   information from key value pairs that will be provided by the Ansible Server as extra-vars during invocation to execute the desired VNF action. If the playbook requires files, they must also be supplied using the methodology detailed in the Ansible Server API.

The Ansible Server will determine if a playbook invoked to execute a VNF action finished successfully or not using the “PLAY_RECAP” summary in Ansible log.  The playbook will be considered to successfully finish only if the “PLAY RECAP” section at the end of playbook execution output has no unreachable hosts and no failed tasks. Otherwise, the playbook will be considered to have failed.

* R-43253 The VNF **MUST** use playbooks designed to allow Ansible Server to infer failure or success based on the “PLAY_RECAP” capability.
* R-50252 The VNF **MUST** write to a specific set of text files that will be retrieved and made available by the Ansible Server If, as part of a VNF action (e.g., audit), a playbook is required to return any VNF information.
* R-51442 The VNF **SHOULD** use playbooks that are designed to automatically ‘rollback’ to the original state in case of any errors for actions that change state of the VNF (e.g., configure). 

ONAP Controller APIs and Behavior
---------------------------------

ONAP Controllers support the following operations which act directly
upon the VNF. Most of these utilize the NETCONF interface. There are
additional commands in use but these either act internally on Controller
itself or depend upon network cloud components for implementation. Those
actions do not put any special requirement on the VNF provider.

The following table summarizes how the VNF must act in response to
commands from ONAP.

Table 8. ONAP Controller APIs and NETCONF Commands

+---------------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| **Action**          | **Description**                                                                                                                                                                                                                                                                  | **NETCONF Commands**                                                                                                                                                                                                          |
+=====================+==================================================================================================================================================================================================================================================================================+===============================================================================================================================================================================================================================+
| Action              | Queries ONAP Controller for the current state of a previously submitted runtime LCM (Lifecycle Management) action.                                                                                                                                                               | There is currently no way to check the request status in NETCONF so action status is managed internally by the ONAP controller.                                                                                               |
|                     |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                               |
| Status              |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                               |
+---------------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Audit, Sync         | Compare active (uploaded) configuration against the current configuration in the ONAP controller. Audit returns failure if different. Sync considers the active (uploaded) configuration as the current configuration.                                                           | The <get-config> operation is used to retrieve the running configuration from the VNF.                                                                                                                                        |
+---------------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Lock,               | Returns true when the given VNF has been locked.                                                                                                                                                                                                                                 | There is currently no way to query lock state in NETCONF so VNF locking and unlocking is managed internally by the ONAP controller.                                                                                           |
|                     |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                               |
| Unlock,             |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                               |
|                     |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                               |
| CheckLock           |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                               |
+---------------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Configure,          | Configure applies a post-instantiation configuration the target VNF or VNFC. ConfigModify updates only a subset of the total configuration parameters of a VNF.                                                                                                                  | The <edit-config> operation loads all or part of a specified configuration data set to the specified target database. If there is no <candidate/> database, then the target is the <running/> database. A <commit> follows.   |
|                     |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                               |
| ConfigModify        |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                               |
+---------------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Health              | Executes a VNF health check and returns the result. A health check is VNF-specific.                                                                                                                                                                                              | The ONAP health check interface is defined over REST and requires the target VNF to expose a standardized HTTP(S) interface for that purpose. See Section 8.c VNF REST APIs.                                                  |
|                     |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                               |
| Check               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                               |
+---------------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| StartApplication,   | ONAP requests application to be started or stopped on the VNF or VNFC. These actions do not need to be supported if (1) the application starts automatically after Configure or if the VM’s are started and (2) the application gracefully shuts down if the VM’s are stopped.   | These commands have no specific NETCONF RPC action.                                                                                                                                                                           |
|                     |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                               |
| StopApplication     |                                                                                                                                                                                                                                                                                  | They can be supported using Ansible or Chef (see Table 9 below).                                                                                                                                                              |
+---------------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| SoftwareUpload,     | Upgrades the target VNF to a new version without interrupting VNF operation.                                                                                                                                                                                                     | These commands have no specific NETCONF RPC action.                                                                                                                                                                           |
|                     |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                               |
| LiveUpgrade         |                                                                                                                                                                                                                                                                                  | They can be supported using Ansible or Chef (see Table 9 below).                                                                                                                                                              |
+---------------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

Table 9 lists the required Chef and Ansible support for commands from
ONAP.

Table 9. ONAP Controller APIs and Chef/Ansible Support

+---------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| **Action**          | **Chef**                                                                                                                                                                                                                                                                                         | **Ansible**                                                                                                                                                                                                                                             |
+=====================+==================================================================================================================================================================================================================================================================================================+=========================================================================================================================================================================================================================================================+
| Action              | Not needed. ActionStatus is managed internally by the ONAP controller.                                                                                                                                                                                                                           | Not needed. ActionStatus is managed internally by the ONAP controller.                                                                                                                                                                                  |
|                     |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                         |
| Status              |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                         |
+---------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Audit, Sync         | VNF Vendor must provide any necessary roles, cookbooks, recipes to retrieve the running configuration from a VNF and place it in the respective Node Objects ‘PushJobOutput’ attribute of all nodes in NodeList when triggered by a chef-client run.                                             | VNF Vendor must provide an Ansible playbook to retrieve the running configuration from a VNF and place the output on the Ansible server in a manner aligned with playbook requirements listed in this document.                                         |
|                     |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                         |
|                     | The JSON file for this VNF action is required to set “PushJobFlag” to “True” and “GetOutputFlag” to “True”. The “Node” JSON dictionary must have the run list populated with the necessary sequence of roles, cookbooks, recipes.                                                                | The PlaybookName must be provided in the JSON file.                                                                                                                                                                                                     |
|                     |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                         |
|                     | The Environment and Node values should contain all appropriate configuration attributes.                                                                                                                                                                                                         | NodeList must list FQDNs of an example VNF on which to execute playbook.                                                                                                                                                                                |
|                     |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                         |
|                     | NodeList must list sample FQDNs that are required to conduct a chef-client run for this VNF Action.                                                                                                                                                                                              |                                                                                                                                                                                                                                                         |
+---------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Lock,               | Not needed. VNF locking and unlocking is managed internally by the ONAP controller.                                                                                                                                                                                                              | Not needed. VNF locking and unlocking is managed internally by the ONAP controller.                                                                                                                                                                     |
|                     |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                         |
| Unlock,             |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                         |
|                     |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                         |
| CheckLock           |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                         |
+---------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Configure,          | VNF Vendor must provide any necessary roles, cookbooks, recipes to apply configuration attributes to the VNF when triggered by a chef-client run. All configurable attributes must be obtained from the Environment and Node objects on the Chef Server.                                         | VNF Vendor must provide an Ansible playbook that can configure the VNF with parameters supplied by the Ansible Server.                                                                                                                                  |
|                     |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                         |
| ConfigModify        | The JSON file for this VNF action should include all configurable attributes in the Environment and/or Node JSON dictionary.                                                                                                                                                                     | The PlaybookName must be provided in the JSON file.                                                                                                                                                                                                     |
|                     |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                         |
|                     | The “PushJobFlag” must be set to “True”.                                                                                                                                                                                                                                                         | The “EnvParameters” and/or “FileParameters” field values should be provided and contain all configurable parameters for the VNF.                                                                                                                        |
|                     |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                         |
|                     | The “Node” JSON dictionary must have the run list populated with necessary sequence of roles, cookbooks, recipes. This action is not expected to return an output.                                                                                                                               | NodeList must list FQDNs of an example VNF on which to execute playbook.                                                                                                                                                                                |
|                     |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                         |
|                     | “GetOutputFlag” must be set to “False”.                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                         |
|                     |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                         |
|                     | NodeList must list sample FQDNs that are required to conduct a chef-client run for this VNF Action.                                                                                                                                                                                              |                                                                                                                                                                                                                                                         |
+---------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Health              | The ONAP health check interface is defined over REST and requires the target VNF to expose a standardized HTTP(S) interface for that purpose. See Section 8.c VNF REST APIs.                                                                                                                     | The ONAP health check interface is defined over REST and requires the target VNF to expose a standardized HTTP(S) interface for that purpose. See Section 8.c VNF REST APIs.                                                                            |
|                     |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                         |
| Check               |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                         |
+---------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| StartApplication,   | VNF Vendor must provide roles, cookbooks, recipes to start an application on the VNF when triggered by a chef-client run. If application does not start, the run must fail or raise an exception. If application is already started, or starts successfully, the run must finish successfully.   | VNF Vendor must provide an Ansible playbook to start the application on the VNF. If application does not start, the playbook must indicate failure. If application is already started, or starts successfully, the playbook must finish successfully.   |
|                     |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                         |
| StopApplication     | For StopApplication, the application must be stopped gracefully (no loss of traffic).                                                                                                                                                                                                            | For StopApplication, the application must be stopped gracefully (no loss of traffic).                                                                                                                                                                   |
+---------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| SoftwareUpload,     | VNF Vendor must provide any necessary roles, cookbooks, recipes to apply a software upgrade to the VNF when triggered by a chef-client run.                                                                                                                                                      | VNF Vendor must provide an Ansible playbook that can apply a software upgrade to the VNF when triggered by the Ansible server                                                                                                                           |
|                     |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                         |
| LiveUpgrade         |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                         |
+---------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

For information purposes, the following ONAP controller functions are
planned in the future:

Table 10. Planned ONAP Controller Functions

+------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| ConfigSave,      | ConfigSave stores the VNF running configuration to a url or file using a specified name. ConfigRestore replaces the VNF running configuration with the configuration previously stored with a url or file with the specified name.                                                                               |
|                  |                                                                                                                                                                                                                                                                                                                  |
| ConfigRestore    |                                                                                                                                                                                                                                                                                                                  |
+==================+==================================================================================================================================================================================================================================================================================================================+
| Reconfigure      | If the audit fails, Reconfigure may be used to be replace the VNF running configuration using a previously uploaded configuration in the ONAP controller.                                                                                                                                                        |
+------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| ConfigStartup    | ConfigStartup is used to store a running configuration to be used when a VNF is rebooted.                                                                                                                                                                                                                        |
+------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| ConfigRecovery   | ConfigRecovery is used to replace the running configuration with a recovery configuration. This recovery configuration is stored in the ONAP Controller and is the configuration uploaded after instantiation. It will only be used if there is no other option to restore the VNF to a working configuration.   |
+------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| StatusQuery      | Executes a VNF status query and returns the result. A status query is VNF-specific.                                                                                                                                                                                                                              |
+------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+


d. Monitoring & Management
===========================

This section addresses data collection and event processing
functionality that is directly dependent on the interfaces provided by
the VNFs’ APIs. These can be in the form of asynchronous interfaces for
event, fault notifications, and autonomous data streams. They can also
be synchronous interfaces for on-demand requests to retrieve various
performance, usage, and other event information.

The target direction for VNF interfaces is to employ APIs that are
implemented utilizing standardized messaging and modeling protocols over
standardized transports. Migrating to a virtualized environment presents
a tremendous opportunity to eliminate the need for proprietary
interfaces for vendor equipment while removing the traditional
boundaries between Network Management Systems and Element Management
Systems. Additionally, VNFs provide the ability to instrument the
networking applications by creating event records to test and monitor
end-to-end data flow through the network, similar to what physical or
virtual probes provide without the need to insert probes at various
points in the network. The VNF vendors must be able to provide the
aforementioned set of required data directly to the ONAP collection
layer using standardized interfaces.

Additional details can be found in the `Data Collection, Analytics, and Events (DCAE) <http://onap.readthedocs.io/en/latest/submodules/dcaegen2.git/docs/index.html>`_ project documentation.

Transports and Protocols Supporting Resource Interfaces
-------------------------------------------------------

Delivery of data from VNFs to ONAP must use the same common transport
mechanisms and protocols for all VNFs. Transport mechanisms and
protocols have been selected to enable both high volume and moderate
volume datasets, as well as asynchronous and synchronous communications
over secure connections. The specified encoding provides
self-documenting content, so data fields can be changed as needs evolve,
while minimizing changes to data delivery.

The term ‘Event Record’ is used throughout this document to represent
various forms instrumentation/telemetry made available by the VNF
including, faults, status events and various other types of VNF
measurements and logs. Headers received by themselves must be used as
heartbeat indicators. The common structure and delivery protocols for
other types of data will be given in future versions of this document as
we get more insight into data volumes and required processing.

In the following guidelines, we provide options for encoding,
serialization and data delivery. Agreements between Service Providers
and VNF vendors shall determine which encoding, serialization and
delivery method to use for particular data sets. The selected methods
must be agreed to prior to the on-boarding of the VNF into ONAP design
studio.

Monitoring & Management Requirements

**VNF telemetry via standardized interface**

* R-51910 The VNF **MUST** provide all telemetry (e.g., fault event records, syslog records, performance records etc.) to ONAP using the model, format and mechanisms described in this section.

**Encoding and Serialization**

* R-19624 The VNF **MUST** encode and serialize content delivered to ONAP using JSON (option 1). High-volume data is to be encoded and serialized using Avro, where Avro data format are described using JSON (option 2) [8]_.

 -  JSON plain text format is preferred for moderate volume data sets (option 1), as JSON has the advantage of having well-understood simple processing and being human-readable without additional decoding. Examples of moderate volume data sets include the fault alarms and performance alerts, heartbeat messages, measurements used for VNF scaling and syslogs.
 -  Binary format using Avro is preferred for high volume data sets (option 2) such as mobility flow measurements and other high-volume streaming events (such as mobility signaling events or SIP signaling) or bulk data, as this will significantly reduce the volume of data to be transmitted. As of the date of this document, all events are reported using plain text JSON and REST.
 -  Avro content is self-documented, using a JSON schema. The JSON schema is delivered along with the data content (http://avro.apache.org/docs/current/ ). This means the presence and position of data fields can be recognized automatically, as well as the data format, definition and other attributes. Avro content can be serialized as JSON tagged text or as binary. In binary format, the JSON schema is included as a separate data block, so the content is not tagged, further compressing the volume. For streaming data, Avro will read the schema when the stream is established and apply the schema to the received content.
 -  In the future, we may consider support for other types of encoding & serialization (e.g., gRPC) based on industry demand.

**Reporting Frequency**

* R-98191 The VNF **MUST** vary the frequency that asynchronous data is delivered based on the content and how data may be aggregated or grouped together. For example, alarms and alerts are expected to be delivered as soon as they appear. In contrast, other content, such as performance measurements, KPIs or reported network signaling may have various ways of packaging and delivering content. Some content should be streamed immediately; or content may be monitored over a time interval, then packaged as collection of records and delivered as block; or data may be collected until a package of a certain size has been collected; or content may be summarized statistically over a time interval, or computed as a KPI, with the summary or KPI being delivered. 
 
  -  We expect the reporting frequency to be configurable depending on the virtual network function’s needs for management. For example, Service Provider may choose to vary the frequency of collection between normal and trouble-shooting scenarios.
  -  Decisions about the frequency of data reporting will affect the size of delivered data sets, recommended delivery method, and how the data will be interpreted by ONAP. However, this should not affect deserialization and decoding of the data, which will be guided by the accompanying JSON schema.

**Addressing and Delivery Protocol**

ONAP destinations can be addressed by URLs for RESTful data PUT. Future data sets may also be addressed by host name and port number for TCP streaming, or by host name and landing zone directory for SFTP transfer of bulk files.

* R-88482 The VNF **SHOULD** use REST using HTTPS delivery of plain text JSON for moderate sized asynchronous data sets, and for high volume data sets when feasible.
* R-84879 The VNF **MUST** have the capability of maintaining a primary and backup DNS name (URL) for connecting to ONAP collectors, with the ability to switch between addresses based on conditions defined by policy such as time-outs, and buffering to store messages until they can be delivered. At its discretion, the service provider may choose to populate only one collector address for a VNF. In this case, the network will promptly resolve connectivity problems caused by a collector or network failure transparently to the VNF.
* R-81777 The VNF **MUST** be configured with initial address(es) to use at deployment time. After that the address(es) may be changed through ONAP-defined policies delivered from ONAP to the VNF using PUTs to a RESTful API, in the same way that other controls over data reporting will be controlled by policy.
* R-08312 The VNF **MAY** use other options which are expected to include
 
 -  REST delivery of binary encoded data sets.
 -  TCP for high volume streaming asynchronous data sets and for other high volume data sets. TCP delivery can be used for either JSON or binary encoded data sets.
 -  SFTP for asynchronous bulk files, such as bulk files that contain large volumes of data collected over a long time interval or data collected across many VNFs. This is not preferred. Preferred is to reorganize the data into more frequent or more focused data sets, and deliver these by REST or TCP as appropriate.
 -  REST for synchronous data, using RESTCONF (e.g., for VNF state polling).

* R-03070 The VNF **MUST**, by ONAP Policy, provide the ONAP addresses as data destinations for each VNF, and may be changed by Policy while the VNF is in operation. We expect the VNF to be capable of redirecting traffic to changed destinations with no loss of data, for example from one REST URL to another, or from one TCP host and port to another.

**Asynchronous and Synchronous Data Delivery**

* R-06924 The VNF **MUST** deliver asynchronous data as data becomes available, or according to the configured frequency.
* R-73285 The VNF **MUST** must encode the delivered data using JSON or Avro, addressed and delivered as described in the previous paragraphs.
* R-42140 The VNF **MUST** respond to data requests from ONAP as soon as those requests are received, as a synchronous response.
* R-34660 The VNF **MUST** use the RESTCONF/NETCONF framework used by the ONAP configuration subsystem for synchronous communication.
* R-86585 The VNF **MUST** use the YANG configuration models and RESTCONF (https://tools.ietf.org/html/draft-ietf-netconf-restconf-09#page-46).
* R-11240 The VNF **MUST** respond with content encoded in JSON, as described in the RESTCONF specification. This way the encoding of a synchronous communication will be consistent with Avro.
* R-70266 The VNF **MUST** respond to an ONAP request to deliver the current data for any of the record types defined in Section 8.d “Data Model for Event Records” by returning the requested record, populated with the current field values. (Currently the defined record types include the common header record, technology independent records such as Fault, Heartbeat, State Change, Syslog, and technology specific records such as Mobile Flow, Signaling and Voice Quality records.  Additional record types will be added in the future as they are standardized and become available.)
* R-46290 The VNF **MUST** respond to an ONAP request to deliver granular data on device or subsystem status or performance, referencing the YANG configuration model for the VNF by returning the requested data elements.
* R-43327 The VNF **SHOULD** use “Modeling JSON text with YANG”, https://trac.tools.ietf.org/id/draft-lhotka-netmod-yang-json-00.html, If YANG models need to be translated to and from JSON. YANG configuration and content can be represented via JSON, consistent with Avro, as described in “Encoding and Serialization” section.   

**Security**

* R-42366 The VNF **MUST** support secure connections and transports.
* R-44290 The VNF **MUST** control access to ONAP and to VNFs, and creation of connections, through secure credentials, log-on and exchange mechanisms.
* R-47597 The VNF **MUST** carry data in motion only over secure connections.
* R-68165 The VNF **MUST** encrypt any content containing Sensitive Personal Information (SPI) or certain proprietary data, in addition to applying the regular procedures for securing access and delivery.

Data Model for Event Records 
-----------------------------

This section describes the data model for the collection of telemetry
data from VNFs by Service Providers (SPs) to manage VNF health and
runtime lifecycle. This data model is referred to as the VNF Event
Streaming (VES) specifications. While this document is focused on
specifying some of the records from the ONAP perspective, there may be
other external bodies using the same framework to specify additional
records. For example, OPNFV has a VES project [9]_ that is looking to
specify records for OpenStack’s internal telemetry to manage Application
(VNFs), physical and virtual infrastructure (compute, storage, network
devices), and virtual infrastructure managers (cloud controllers, SDN
controllers). Note that any configurable parameters for these data
records (e.g., frequency, granularity, policy-based configuration) will
be managed using the “Configuration” framework described in the prior
sections of this document.

The Data Model consists of:

-  Common Header Record: This data structure precedes each of the
   Technology Independent and Technology Specific records sections of
   the data model.

-  Technology Independent Records: This version of the document
   specifies the model for Fault, Heartbeat, State Change, Syslog,
   Threshold Crossing Alerts, and VF Scaling\* (short for
   measurementForVfScalingFields) records. In the future, these may be
   extended to support other types of technology independent records.
   Each of these records allows additional fields (name/ value pairs)
   for extensibility. The vendors can use these vendor-specific
   additional fields to provide additional information that may be
   relevant to the managing systems.

-  Technology Specific Records: This version of the document specifies
   the model for Mobile Flow records, Signaling and Voice Quality
   records. In the future, these may be extended to support other types
   of records (e.g., Network Fabric, Security records, etc.). Each of
   these records allows additional fields (name/value pairs) for
   extensibility. The VNF vendors can use these VNF-specific additional
   fields to provide additional information that may be relevant to the
   managing systems. A placeholder for additional technology specific
   areas of interest to be defined in the future documents has been
   depicted.

|image0|
Figure 1. Data Model for Event Records

Event Records - Data Structure Description
------------------------------------------

The data structure for event records consists of:

-  a Common Event Header block;

-  zero or more technology independent domain blocks; and

   -  e.g., Fault domain, State Change domain, Syslog domain, etc.

-  zero or more technology specific domain blocks.

   -  e.g., Mobile Flow domain, Signaling domain, Voice Quality domain,
      etc.

Note: Heartbeat records would only have the Common Event Header block.
An optional heartbeat domain is available if required by the heartbeat
implementation.

Common Event Header
~~~~~~~~~~~~~~~~~~~~~

The common header that precedes any of the domain-specific records
contains information identifying the type of record to follow,
information about the sender and other identifying characteristics
related to timestamp, sequence number, etc.

Technology Independent Records – Fault Fields
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The Fault Record, describing a condition in the Fault domain, contains
information about the fault such as the entity under fault, the
severity, resulting status, etc.

Technology Independent Records – Heartbeat Fields
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The Heartbeat Record provides an optional structure for communicating
information about heartbeat or watchdog signaling events. It can contain
information about service intervals, status information etc. as required
by the heartbeat implementation.

Technology Independent Records – State Change Fields
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The State Change Record provides a structure for communicating
information about data flow through the VNF. It can contain information
about state change related to physical device that is reported by VNF.
As an example, when cards or port name of the entity that has changed
state.

Technology Independent Records – Syslog Fields
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The Syslog Record provides a structure for communicating any type of
information that may be logged by the VNF. It can contain information
about system internal events, status, errors, etc.

Technology Independent Records – Threshold Crossing Alert Fields
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The Threshold Crossing Alert (TCA) Record provides a structure for
communicating information about threshold crossing alerts. It can
contain alert definitions and types, actions, events, timestamps and
physical or logical details.

Technology Independent Records - VF Scaling Fields
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The VF Scaling\* (short for measurementForVfScalingFields) Record
contains information about VF and VNF resource structure and its
condition to help in the management of the resources for purposes of
elastic scaling.

Technology Independent Records – otherFields
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The otherFields Record defines fields for events belonging to the
otherFields domain of the Technology Independent domain enumeration.
This record provides a mechanism to convey a complex set of fields
(possibly nested or opaque) and is purely intended to address
miscellaneous needs such as addressing time-to-market considerations or
other proof-of-concept evaluations.  Hence, use of this record type is
discouraged and should be minimized.

Technology Specific Records – Mobile Flow Fields
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The Mobile Flow Record provides a structure for communicating
information about data flow through the VNF. It can contain information
about connectivity and data flows between serving elements for mobile
service, such as between LTE reference points, etc.

Technology Specific Records – Signaling Fields
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The Signaling Record provides a structure for communicating information
about signaling messages, parameters and signaling state. It can contain
information about data flows for
`signaling <https://en.wikipedia.org/wiki/Signaling_%28telecommunications%29>`__
and controlling
`multimedia <https://en.wikipedia.org/wiki/Multimedia>`__ communication
`session <https://en.wikipedia.org/wiki/Session_%28computer_science%29>`__\ s
such as `voice <https://en.wikipedia.org/wiki/Telephone_call>`__ and
`video calls <https://en.wikipedia.org/wiki/Video_call>`__.

Technology Specific Records – Voice Quality Fields
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The Voice Quality Record provides a structure for communicating
information about voice quality statistics including media connection
information, such as transmitted octet and packet counts, packet loss,
packet delay variation, round-trip delay, QoS parameters and codec
selection.

Technology Specific Records – Future Domains
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The futureDomains Record is a placeholder for additional technology
specific areas of interest that will be defined and described in the
future documents.

Data Structure Specification of the Event Record
------------------------------------------------

For additional information on the event record formats of the data
structures mentioned above, please refer to `VES Event
Listener <https://github.com/att/evel-test-collector/tree/master/docs/att_interface_definition>`__.

.. [2]
   https://github.com/mbj4668/pyang

.. [3]
   Decision on which Chef Server instance associates with a VNF will be
   made on a case-by-case basis depending on VNF, access requirements,
   etc. and are outside the scope of this document. The specific
   criteria for this would involve considerations like connectivity and
   access required by the VNF, security, VNF topology and proprietary
   cookbooks.

.. [4]
   Recall that the Node Object **is required** to be identical across
   all VMs of a VNF invoked as part of the action except for the “name”.

.. [5]
   Decision on which Ansible Server to use may happen on a case-by-case
   basis depending on VNF, access requirements etc. and are outside the
   scope of this document. The specific criteria for this could involve
   considerations like connectivity and access required by the VNF,
   security, VNF topology and proprietary playbooks.

.. [6]
   Upstream elements must provide the appropriate FQDN in the request to
   ONAP for the desired action.

.. [7]
   Multiple ONAP actions may map to one playbook.

.. [8]
   This option is not currently supported in ONAP and it is currently
   under consideration.

.. [9]
   https://wiki.opnfv.org/display/PROJ/VNF+Event+Stream

.. [10]
   The “name” field is a mandatory field in a valid Chef Node Object
   JSON dictionary.

.. |image0| image:: Data_Model_For_Event_Records.png
      :width: 7in
      :height: 8in