goflow

README

GoFlow

Goflow is a microservice orchestration workflows inspired from Netflix Conductor & Erlang's FSM

STILL IN DEVELOPMENT!

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Netflix Conductor

Overview

The Netflix Content Platform Engineering team runs a number of business processes which are driven by asynchronous orchestration of tasks executing on microservices.

Objectives

• Blueprint based, json DSL
• Workflow management including tracking
• Able to delay the task & resume
• Operate over HTTP or other transports ex: GRPC

---

FSM

Example Transitions

From Erlang's FSM Documentation:

A FSM can be described as a set of relations of the form:

State(S) x Event(E) -> Actions (A), State(S')

Flows:

State(current) -> Event (triggered) -> Action (worker) -> State(next)

If we are in state S and the event E occurs, we should perform the action of A and move the transition to next state S'.

References:

• http://erlang.org/documentation/doc-4.8.2/doc/design_principles/fsm.html
• http://cloudmark.github.io/FSM/
• https://levelup.gitconnected.com/implement-a-finite-state-machine-in-golang-f0438b6bc0a8

---

JSON DSL

Workflow Metadata

{
  "project": "goflow",
  "activity": "inquiry",
  "states": [
    "calculate_balance",
    "get_product",
	"calculate_voucher"
  ],
	"actions": [
		{
			"name": "calculate_balance",
			"type": "sync"
		},
		{
			"name": "get_product",
			"type": "sync"
		},
		{
			"name": "calculate_voucher",
			"type": "sync"
		}
	],
	"transitions": [
		{
			"current": "init",
			"event": "start",
			"action": "calculate_balance",
			"next": "calculate_balance"
		},
		{
			"current": "calculate_balance",
			"event": "success",
			"action": "continue",
			"next": "get_product"
		},
		{
			"current": "calculate_balance",
			"event": "error",
			"action": "continue",
			"next": "done"				
		},
		{
			"current": "get_product",
			"event": "start",
			"action": "get_product",
			"next": "get_product"		
		},
		{
			"current": "get_product",
			"event": "success",
			"action": "continue",
			"next": "calculate_voucher"		
		},
		{
			"current": "calculate_voucher",
			"event": "start",
			"action": "continue",
			"next": "calculate_voucher"		
		},
	]
}

Worker Metadata

{
	"project": "goflow",
	"activity": "inquiry",
	"workers": [
		{
			"name": "calculate_balance",
			"workerEndpoint": "worker_url",
			"retryCount": 3,
			"responseTimeout": 5,
			"priority": 1
		},
		{
			"name": "calculate_balance",
			"workerEndpoint": "worker_url_2",
			"retryCount": 3,
			"responseTimeout": 5,
			"priority": 2
		},
		{
			"name": "get_product",
			"workerEndpoint": "worker_url",
			"retryCount": 2,
			"responseTimeout": 5,
			"priority": 1
		},
		{
			"name": "calculate_voucher",
			"workerEndpoint": "worker_url",
			"retryCount": 5,
			"responseTimeout": 5,
			"priority": 1
		},
		{
			"name": "done",
			"workerEndpoint": "worker_url",
			"retryCount": 5,
			"responseTimeout": 5,
			"priority": 1		
		}
	]
}