Workflow - a library organizes steps with dependencies into DAG (Directed-Acyclic-Graph) for Go

Overview

Strongly encourage everyone to read examples in the examples directory to have a quick understanding of how to use this library.

go-workflow helps Go developers organize steps with dependencies into a Directed-Acyclic-Graph (DAG).

• It provides a simple and flexible way to define and execute a workflow.
• It is easy to implement steps and compose them into a composite step.
• It uses goroutine to execute steps concurrently.
• It supports retry, timeout, and other configurations for each step.
• It supports callbacks to hook before / after each step.

See it in action:

package yours

import (
    "context"

    flow "github.com/Azure/go-workflow"
)

type Step struct{ Value string }

// All required for a step is `Do(context.Context) error`
func (s *Step) Do(ctx context.Context) error {
    fmt.Println(s.Value)
    return nil
}

func main() {
    // declare steps
    var (
        a = new(Step)
        b = &Step{Value: "B"}
        c = flow.Func("declare from anonymous function", func(ctx context.Context) error {
            fmt.Println("C")
            return nil
        })
    )
    // compose steps into a workflow!
    w := new(flow.Workflow)
    w.Add(
        flow.Step(b).DependsOn(a),     // use DependsOn to define dependencies
        flow.Steps(a, b).DependsOn(c), // final execution order: c -> a -> b

        // other configurations, like retry, timeout, condition, etc.
        flow.Step(c).
            Retry(func(ro *flow.RetryOption) {
                ro.Attempts = 3 // retry 3 times
            }).
            Timeout(10*time.Minute), // timeout after 10 minutes

        // use Input to change step at runtime
        flow.Step(a).Input(func(ctx context.Context, a *Step) error {
            a.Value = "A"
            return nil
        }),
    )
    // execute the workflow and block until all steps are terminated
    err := w.Do(context.Background())
}

Contributing

This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit https://cla.opensource.microsoft.com.

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This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact [email protected] with any additional questions or comments.

Trademarks

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