Human consumable text format for simple workflows

README.md

Motivation

Allow developers to specify workflows without the need for installing additional tooling such as a modeler.

Goals

• It should be easy to define a simple workflow with a text editor only
• The format must map down directly to BPMN
• The format must be based on an existing text based format like (XML, JSON, YAML, TOML, ...)

Non-Goals

• The format should not have the ambition to replace BPMN or reach BPMN's level of expressiveness
• The format must not introduce any new concepts which are not present in BPMN
• The format should not be workflow-engine agnostic. It should target zeebe.io directly and natively expose it's features. It should not have a concept of "Extension Elements".

example.yaml

name: Order Processing
description: >
    This workflow describes the processing of an order.
    There can be more text here...

tasks:
    - id:   COLLECT_MONEY
      type: process-payment
      inputParameters:
          - source: $.order.paymentData
      
    - id:   FETCH_ITEMS
      type: item-management
      headers:
          - operation-type: FETCH
      inputParameters:
          - source: $.order.itemData
      
    - id:   SHIP_PARCEL
      type: shipment-inbound
      
flow:
    - { from: COLLECT_MONEY, to: FETCH_ITEMS } 
    - { from: FETCH_ITEMS, to: SHIP_PARCEL }

      

related-work.md

Related Work

Amazon States Language

The language used by AWS Step Functions.

Reference:

https://states-language.net/spec.html

Example:

"LookupCustomerInfo": {
  "Type": "Parallel",
  "Branches": [
    {
      "StartAt": "LookupAddress",
      "States": {
        "LookupAddress": {
          "Type": "Task",
          "Resource": 
            "arn:aws:lambda:us-east-1:123456789012:function:AddressFinder",
          "End": true
        }
      }
    },
    {
      "StartAt": "LookupPhone",
      "States": {
        "LookupPhone": {
          "Type": "Task",
          "Resource": 
            "arn:aws:lambda:us-east-1:123456789012:function:PhoneFinder",
          "End": true
        }
      }
    }
  ],
  "Next": "NextState"
}

Netflix Conductor

JSON DSL used by Netflix Conductor

Reference:

https://netflix.github.io/conductor/metadata/

Example

{
  "name": "encode_and_deploy",
  "description": "Encodes a file and deploys to CDN",
  "version": 1,
  "tasks": [
    {
      "name": "encode",
      "taskReferenceName": "encode",
      "type": "SIMPLE",
      "inputParameters": {
        "fileLocation": "${workflow.input.fileLocation}"
      }
    },
    {
      "name": "deploy",
      "taskReferenceName": "d1",
      "type": "SIMPLE",
      "inputParameters": {
        "fileLocation": "${encode.output.encodeLocation}"
      }

    }
  ],
  "outputParameters": {
    "cdn_url": "${d1.output.location}"
  },
  "schemaVersion": 2
}