The BPMN for Function Orchestration (BPMN4FO) prototype enables users to model serverless function orchestration models using BPMN (formerly called MaToSWo). Serverless function orchestration models are then used to generate corresponding orchestrator-specific function orchestration models, making use of platform-specific serverless function orchestration constructs, for the supported function orchestrators. Currently, BPMN4FO supports four orchestrators:
- Step Functions (Amazon Web Services)
- Durable Functions (Microsoft Azure)
- Apache Openwhisk Composer for orchestrating functions on Apache Openwhisk
- IBM Composer (based on Apache Openwhisk Composer) for orchestrating functions on IBM Cloud Functions
BPMN4FO makes the generated workflow definitions available for download as a zip archive, right beneath the modeling area of the user interface.
- NodeJS, tested with v12.19.0
- Clone this repository
- Navigate to the main folder, containing
package.json - Run
npm install - Run
npm run devto start a local development server at port9013, and serve the BPMN4FO prototype - To execute the tests, run
npm run test
The BPMN4FO makes use of bpmn-js for modeling the BPMN function orchestrations graphically.
This functionality consists of a graphical BPMN editor and related functions, such as model import and export as xml files.
Since BPMN4FO uses customized BPMN elements with additional properties, bpmn-js is extended to accommodate this.
The app/descriptors and app/provider folders contain these customizations.
bpmn-js is set up via in the top-level app/index.html and app/index.js files.
The function orchestrations modeled in the user interface's modeling area can be transformed into the orchestrator-specific models with the help of the app/orchestrator-generation/BpmnModelOrchestratorTransformation class, invoked by the user interface.
The components of BPMN4FO are each separated into their own folders.
The orchestrator-generation/extractors component is invoked first with the user-created BPMN model as input.
The model is then converted into a simplified version, where each supported model element is handled separately.
This simplified model is handed to the orchestrator-generation/builders component, which builds a control flow hierarchy from it.
The control flow hierarchy is defined in the orchestrator-generation/model component and represents the control flow structure of the modeled function orchestration.
The control flow hierarchy has separate classes for each supported control flow construct and allows nesting them within each other to create a tree-like structure.
This control flow hierarchy is then traversed by the traversers/control-flow-hierarchy component.
The traversers/control-flow-hierarchy/validators component validates the control flow hierarchy and the traversers/control-flow-hierarchy/generators component generates the orchestrator-specific models from it.
For this they make use of the traversers/condition/generators component to generate conditional expressions used in the function orchestration models.
The generated function orchestration models are then made available as .zip archive to the user.
The project license is Apache License 2.0.
Initialization code for the bpmn-js library and the user interface is based on the code from the properties-panel-extension example project.