Simple Workflow Framework in Go

simple-workflow-go is a lightweight and efficient workflow framework designed for easy integration into applications written in Go. This framework simplifies the orchestration of complex processes, enabling developers to manage workflow states, activities, and tasks seamlessly.

Demo

Experience the framework in action with our visual demo showcasing its capabilities and features!

Key Features

• Backend Support: The framework supports various backend systems for persisting workflow state, including PostgreSQL (PSQL).
• Manage Activities: Define service calls, I/O operations, and long-running tasks using non-deterministic activity functions.
• Orchestration: Easily orchestrate activities into workflows using a clear structure and concise syntax.
• Worker Management: Create and manage activity and workflow workers to handle execution with a robust design.
• Debugging Capability: Debug running workflows efficiently by querying user-defined variables and inspecting the workflow state.

Getting Started

The framework allows you to initialize your backend using a PSQL server. Here’s a quick example of how to set up the PSQL backend:

const (
    DbHost     = "localhost"
    DbPort     = 5432
    DbName     = "postgres"
    DbUser     = "user"
    DbPassword = "123456"
)

func InitPSQLBackend(logger *zap.Logger) (backend.Backend, error) {
    hostname, err := os.Hostname()
    if err != nil { return nil, err }
    db, err := psql.Connect(DbHost, DbPort, DbUser, DbPassword, DbName, nil)
    if err != nil { return nil, err }
    err = psql.PrepareDB(db) // auto-create table if not exists
    if err != nil { return nil, err }
    dataConverter := dataconverter.NewJsonDataConverter()
    be := psql.NewPSQLBackend(hostname, 5*time.Minute, dataConverter, db, logger)
    return be, nil
}

Define activities to carry out specific tasks. Here’s an example of a payment activity:

type PaymentInput struct {
    Value int64
}

func PaymentActivity(ctx context.Context, input *PaymentInput) (*Void, error) {
    r := rand.Intn(100)
    if r < 30 { // 30% chance of failure
        return &Void{}, nil
    } else {
        return nil, errors.New("payment failed")
    }
}

Build workflows by orchestrating these activities, handling errors and iterating through cycles:

func SubscriptionWorkflow(ctx context.Context, input *SubscriptionWorkflowInput) (*SubscriptionWorkflowOutput, error) {
    // Workflow logic here...
}

Workers

Workers are integral to executing activities and workflows. You can create both activity and workflow workers:

aw, err := worker.NewActivityWorkersBuilder().
    WithName("demo activity worker").
    WithBackend(be).
    WithLogger(logger).
    RegisterActivities(PaymentActivity).
    WithActivityWorkerOpts(activity_worker.WithTaskProcessorMaxBackoffInterval(1 * time.Minute)).
    Build()

Workflow Execution

Launching workflows is straightforward. Use the ScheduleWorkflow method:

err := client.ScheduleWorkflow(ctx, be, SubscriptionWorkflow, &SubscriptionWorkflowInput{
    TotalAmount: totalAmount,
    Cycles:      cycles,
}, client.WorkflowScheduleOptions{
    WorkflowID: workflowID,
    Version:    "1",
})

Debugging Workflows

To debug a workflow, utilize the WorkflowDebugger feature that allows you to inspect runtime variables and the current state:

dbg := debug.NewWorkflowDebugger(be)
vars, err := dbg.QueryUserDefinedVars(SubscriptionWorkflow, workflowID)

Example Projects

Explore various examples under the examples directory to see how to implement and utilize the simple-workflow-go framework effectively.

Start building efficient workflows today with simple-workflow-go!