Nexus SyncOperation context propagation

nexus-context-propagation/README.md

@@ -39,6 +39,8 @@ go run ./starter \
 
 which should result in:
 ```
-2025/02/27 12:57:40 Started workflow WorkflowID nexus_hello_caller_workflow_20240723195740 RunID c9789128-2fcd-4083-829d-95e43279f6d7
-2025/02/27 12:57:40 Workflow result: ¡Hola! Nexus, caller-id: samples-go 👋
+2025/02/28 14:54:29 Started workflow WorkflowID nexus_hello_caller_workflow_20250228145225 RunID 01954ec2-d1d2-72b7-a6cc-a83de5421754
+2025/02/28 14:54:30 Workflow result: Nexus Echo 👋, caller-id: samples-go
+2025/02/28 14:54:30 Started workflow WorkflowID nexus_hello_caller_workflow_20250228145430 RunID 01954ec4-bc4d-7dac-a311-d4ceacacfa9a
+2025/02/28 14:54:31 Workflow result: ¡Hola! Nexus, caller-id: samples-go 👋
 ```

nexus-context-propagation/caller/starter/main.go

@@ -27,16 +27,22 @@ func main() {
 	}
 	defer c.Close()
 	ctx := context.Background()
-	workflowOptions := client.StartWorkflowOptions{
-		ID:        "nexus_hello_caller_workflow_" + time.Now().Format("20060102150405"),
-		TaskQueue: caller.TaskQueue,
-	}
 
 	ctx = context.WithValue(ctx, ctxpropagation.PropagateKey, ctxpropagation.Values{
 		Key:   "caller-id",
 		Value: "samples-go",
 	})
-	wr, err := c.ExecuteWorkflow(ctx, workflowOptions, caller.HelloCallerWorkflow, "Nexus", service.ES)
+
+	runWorkflow(ctx, c, caller.EchoCallerWorkflow, "Nexus Echo 👋")
+	runWorkflow(ctx, c, caller.HelloCallerWorkflow, "Nexus", service.ES)
+}
+
+func runWorkflow(ctx context.Context, c client.Client, workflow interface{}, args ...interface{}) {
+	workflowOptions := client.StartWorkflowOptions{
+		ID:        "nexus_hello_caller_workflow_" + time.Now().Format("20060102150405"),
+		TaskQueue: caller.TaskQueue,
+	}
+	wr, err := c.ExecuteWorkflow(ctx, workflowOptions, workflow, args...)
 	if err != nil {
 		log.Fatalln("Unable to execute workflow", err)
 	}

nexus-context-propagation/caller/worker/main.go

@@ -43,6 +43,7 @@ func main() {
 	})
 
 	w.RegisterWorkflow(caller.HelloCallerWorkflow)
+	w.RegisterWorkflow(caller.EchoCallerWorkflow)
 
 	err = w.Run(worker.InterruptCh())
 	if err != nil {

nexus-context-propagation/handler/app.go

@@ -14,9 +14,26 @@ import (
 	"github.com/temporalio/samples-go/nexus/service"
 )
 
+// NewSyncOperation is a meant for exposing simple RPC handlers.
+var EchoOperation = nexus.NewSyncOperation(service.EchoOperationName, func(ctx context.Context, input service.EchoInput, options nexus.StartOperationOptions) (service.EchoOutput, error) {
+	// Values may be extracted from the context in the Operation handler body.
+	values, ok := ctx.Value(ctxpropagation.PropagateKey).(ctxpropagation.Values)
+	if ok {
+		input.Message += ", " + values.Key + ": " + values.Value
+	}
+	// Use temporalnexus.GetClient to get the client that the worker was initialized with to perform client calls
+	// such as signaling, querying, and listing workflows. Implementations are free to make arbitrary calls to other
+	// services or databases, or perform simple computations such as this one.
+	return service.EchoOutput(input), nil
+})
+
 // Use the NewWorkflowRunOperation constructor, which is the easiest way to expose a workflow as an operation.
 // See alternatives at https://pkg.go.dev/go.temporal.io/sdk/temporalnexus.
 var HelloOperation = temporalnexus.NewWorkflowRunOperation(service.HelloOperationName, HelloHandlerWorkflow, func(ctx context.Context, input service.HelloInput, options nexus.StartOperationOptions) (client.StartWorkflowOptions, error) {
+	// Values may be extracted from the context in the Operation handler body if necessary, this sample propagates
+	// the context to the handler workflow.
+	// values, ok := ctx.Value(ctxpropagation.PropagateKey).(ctxpropagation.Values)
+
 	return client.StartWorkflowOptions{
 		// Workflow IDs should typically be business meaningful IDs and are used to dedupe workflow starts.
 		// For this example, we're using the request ID allocated by Temporal when the caller workflow schedules
@@ -27,6 +44,7 @@ var HelloOperation = temporalnexus.NewWorkflowRunOperation(service.HelloOperatio
 })
 
 func HelloHandlerWorkflow(ctx workflow.Context, input service.HelloInput) (service.HelloOutput, error) {
+	// Values may be extracted from the handler workflow context.
 	values, ok := ctx.Value(ctxpropagation.PropagateKey).(ctxpropagation.Values)
 	if ok {
 		input.Name += ", " + values.Key + ": " + values.Value

nexus-context-propagation/handler/worker/main.go

@@ -47,7 +47,7 @@ func main() {
 		},
 	})
 	service := nexus.NewService(service.HelloServiceName)
-	err = service.Register(handler.HelloOperation)
+	err = service.Register(handler.HelloOperation, handler.EchoOperation)
 	if err != nil {
 		log.Fatalln("Unable to register operations", err)
 	}