Purpose and Scope

Purpose

As a Designer, I should be able to

1. Create Workflow
2. Edit the Workflow Details
3. Collaborate with other users
4. Submit the workflow for Certification.
5. Distribute the workflow

We want to create a way where the integration of a new designer is seamless from the SDC perspective, we want to create a generic way where we can onboard new designers without needing to add specific code.

Scope

Workflow designer will be built as a pluggable designer with SDC as the host application.

The solution will provide several options for showing the designer as part of SDC.

The communication between the SDC and back-end side will be based on the external API’s SDC exposes.

Assumptions

In order to integrate between SDC and external workflow designer, the integrated external workflow has to be pre-configured at least with the following parameters:

1. SSL: the traffic should be SSL traffic
2. The communication between the application will be done based on RestAPI
3. External Workflow designer system must support iFrame.
4. Correlation between both SDC and external workflow based on ID's
5. External workflow designer system should be highly available
6. The workflow designer service is loosely integrated with SDC
7. The workflow designer service should come with version management built-in

Deployment

Workflow Frontend

The frontend will be deployed separately from the backend, particularly due to architectural constraints related to security.

Workflow Backend

Workflow designer backends will be maintained separately in the code base but deployed as a single deployment unit.

Workflow Versioning

An only major version is supported.

Lifecycle Behavior

The lifecycle of the workflow begins with the creation of the workflow.

Once the creator finishes the updates – he should check-in the asset.

An iterative flow of checkout-update-checkin can be performed until the workflow is ready to be certified.

Every checkout of the resource increases the minor version of it. Certification of the resource increases the major version.

Limitation

• once you certify the model, you cannot change or edit the model.
• when the model is certified and a new major version is created, all the minor versions are deleted from SDC

Use Cases

Workflow as a first-class citizen

1. Create new workflow
2. Save workflow
3. Versioning workflow
4. Createnewworkflowversion
5. Edit workflow
6. Associate workflow

Workflow in context of VF

1. Create Workflow Context in of VF based on Operation.
2. Launch workflow Designer
3. Submit VNF – Include Workflow Artifacts in CSAR.
4. Edit Operations – Update Workflow Context
5. Delete Operations – Update Workflow Context
6. New VNF Version Operations – Update Workflow Context

Collaborate Workflow

1. Versioning workflow
2. Createnewworkflowversion

Submit the workflow for Certification

1. Certify workflow

Distribution Workflow as part of

1. Tosca – Adding the input

2. Distribute WF as a separate artifact in the context of VF CSAR OOS

Operation on VF

1. Associate workflow to operation
2. Change to associated workflow
3. Adding inputs to the operation
4. Assign inputs to the operation
5. Save workflow artifact in SDC

Solution Overview

The solution will position SDC as a hosting application providing a design platform for workflows.

Each Workflow designer studio will be treated as an external service/application/system in the eyes of SDC.

SDC will call API’s forget, search for the external workflow application, assigned to the service/VF operations with the workflow artifacts.

Generic Workflow Logical Model

SDC extensibility

SDC provides extensibility framework architecture to achieve micro-service. 

Each external workflow studio must have a set of a micro-service with its own Front-End(UI) Back-End (Business logic) and Repository (Database)

Because SDC is a multi-tier application we expect external different workflows to uphold the same architecture.

Functional Specifications

Workflow Designer

Architecture Overview

1. SDC is a container
2. Workflow Designer is a set of micro-services supplying both UI (editor) and business logic backend.
   1. for BPMN.io (a.k.a ZTE) there is only FE without BE and the communication is with the Workflow Designer BE (CRUD API's)
   2. for Other Designer, Other providing their own FE and BE and the communication is with Other BE with Workflow Designer BE (CRUD API's)
3. The Editor exposes an operational API’s (CRUD) which will be invoked by the Workflow Manager (Save, Check-in, Check-out etc).
4. The Repository is optional and the external workflow can use the Workflow designer BE repository

Workflow Designer - Integrated Solution with ONAP

Workflow Designer - BPMN.io Editor

API's exposed by External Workflow BE

Functional Specification

Workflow Designer BE will expose API’stosupportoperationsoftheworkflow such as ‘get’ and 'search'.

Protocol

The protocol is RESTful GET API directly.

Format

The format is JSON object

Operational SDC API’s

1. Get Workflow Content by WF versionId that are in 'CERTIFIED' state
2. List Workflow Content that are in 'CERTIFIED' state
3. Search Workflow Content
4. Create New Workflow
5. Create New Version of existing Workflow
6. Copy Workflow
7. Update Workflow
8. Save Workflow into SDC

API’s exposed by External Workflow

Functional Flows

Create workflow (first-class citizen)

Sequence diagram

Limitations:

1. until the workflow is not in status "CERTIFY" it editable - the workflow system must be able to save intermediate state for the workflow.
2. once the workflow is in "CERTIFY" mode it cannot be edit
3. there are no mentions for versioning management and the assumption is that the workflow application has version management OOB.

Create workflow (from Operation in context of VF)

Sequence diagram

High-level flow

Associate workflow to an Operation and Save Artifact

Sequence diagram

High-level flow

Save Operation and Save Artifact (Download) (deprecated)

Sequence diagram

High-level flow

Related API's

Certify (Submit) VF/Operation

Sequence diagram

Edit Operations – Update Workflow from the VF/Operation

The user has created an operation, worked on the workflow, went back to the operation and changed inputs/outputs.worked on workflow and submitted VNF

Multiple changes to operation in a version of VNF

Sequence diagram

New VNF Version Operations – Update Workflow Context from the VF/Operation

The user created a new version of VNF and started to edit a previously existing operation change inputs/outputs. update workflow and submit VNF.

Changing an operation in a different version of VNF

Sequence diagram

High-level flow

Workflow Data Model Metadata