Golang Hello World

This section provides step by step instructions on how to write and run a HelloWorld with Golang.

For complete, ready to build samples covering all the key Cadence concepts go to Cadence-Samples (opens new window) for more examples.

You can also review Cadence-Client (opens new window) and go-docs (opens new window) for more documentation.

Include Golang cadence-client dependency

Add cadence-client library to your project by running the command:

go get go.uber.org/cadence

Implement HelloWorld Workflow

package main
import (
	"context"
	"time"
	"go.uber.org/cadence/activity"
	"go.uber.org/cadence/workflow"
	"go.uber.org/zap"
)
/**
 * This is the hello world workflow sample.
 */
// ApplicationName is the task list for this sample
const ApplicationName = "helloWorldGroup"
// helloWorkflow workflow decider
func helloWorldWorkflow(ctx workflow.Context, name string) error {
	ao := workflow.ActivityOptions{
		ScheduleToStartTimeout: time.Minute,
		StartToCloseTimeout:    time.Minute,
		HeartbeatTimeout:       time.Second * 20,
	}
	ctx = workflow.WithActivityOptions(ctx, ao)
	logger := workflow.GetLogger(ctx)
	logger.Info("helloworld workflow started")
	var helloworldResult string
	err := workflow.ExecuteActivity(ctx, helloWorldActivity, name).Get(ctx, &helloworldResult)
	if err != nil {
		logger.Error("Activity failed.", zap.Error(err))
		return err
	}
	logger.Info("Workflow completed.", zap.String("Result", helloworldResult))
	return nil
}
func helloWorldActivity(ctx context.Context, name string) (string, error) {
	logger := activity.GetLogger(ctx)
	logger.Info("helloworld activity started")
	return "Hello " + name + "!", nil
}

Implement Worker

Follow the worker documentation or the samples (opens new window) to implement the worker.

Start the Worker and Workflow

Build the worker program with your project. You can follow the way in the sample (opens new window).

Then start the worker:

./bin/helloworld -m worker

And start a workflow:

./bin/helloworld

What is Next

Now you have completed the tutorials. You can continue to explore the key concepts in Cadence, and also how to use them with Go Client