feat: TLS Helloworld sample for gRPC calls to cadence (#114)

* TLS Helloworld sample for gRPC calls to cadence

Author: vishwa-uber

.gitignore

@@ -15,3 +15,6 @@ vendor/
 # Executables produced by cadence-samples repo
 bin/
 docker-compose.yml
+
+# Credentials
+new_samples/client_samples/helloworld_tls/credentials/

new_samples/client_samples/helloworld_tls/README.md

@@ -0,0 +1,65 @@
+## Pre-requisites
+
+Follow this document to start cadence server:
+https://github.com/cadence-workflow/cadence/blob/e1267de12f8bc670fc84fab456d3495c8fc2f8a8/CONTRIBUTING.md#L1
+
+1. **Build tools in cadence server**
+   ```bash
+   make bins
+   ```
+
+2. **Start cassandra**
+   ```bash
+   docker compose -f ./docker/dev/cassandra.yml up -d
+   ```
+
+3. **Install schema**
+   ```bash
+   make install-schema
+   ```
+
+4. **Start cadence server with TLS**
+   ```bash
+   ./cadence-server --env development --zone tls start
+   ```
+
+## Running the Sample
+
+### Step 1: Download Certificates
+Download certificates from config/credentials of cadence server and place them in below folder
+
+```bash
+new_samples/client_samples/helloworld_tls/credentials
+```
+
+### Step 2: Register the Domain
+Before running workflows, you must register the "default" domain:
+
+```bash
+cd new_samples/client_samples/helloworld_tls
+go run register_domain.go
+```
+
+Expected output:
+```
+Successfully registered domain  {"domain": "default"}
+```
+
+If the domain already exists, you'll see:
+```
+Domain already exists  {"domain": "default"}
+```
+
+### Step 3: Run the Sample
+In another terminal:
+```bash
+cd new_samples/client_samples/helloworld_tls
+go run hello_world_tls.go
+```
+
+## References
+
+- [Cadence Official Certificates](https://github.com/cadence-workflow/cadence/tree/master/config/credentials)
+- [Cadence Documentation](https://cadenceworkflow.io/)
+- [Go TLS Package](https://pkg.go.dev/crypto/tls)
+

new_samples/client_samples/helloworld_tls/hello_world_tls.go

@@ -0,0 +1,86 @@
+package main
+
+import (
+	"context"
+	"crypto/tls"
+	"crypto/x509"
+	"fmt"
+	"os"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/uber-common/cadence-samples/new_samples/worker"
+	"go.uber.org/cadence/.gen/go/shared"
+	"go.uber.org/yarpc/transport/grpc"
+	"go.uber.org/zap"
+	"google.golang.org/grpc/credentials"
+)
+
+func main() {
+	withTLSDialOption, err := withTLSDialOption()
+	if err != nil {
+		panic(err)
+	}
+
+	cadenceClient := worker.BuildCadenceClient(withTLSDialOption)
+	logger := worker.BuildLogger()
+
+	domain := "default"
+	tasklist := "default-tasklist"
+	workflowID := uuid.New().String()
+	requestID := uuid.New().String()
+	executionTimeout := int32(60)
+	closeTimeout := int32(60)
+
+	workflowType := "cadence_samples.HelloWorldWorkflow"
+	input := []byte(`{"message": "Uber"}`)
+
+	req := shared.StartWorkflowExecutionRequest{
+		Domain:     &domain,
+		WorkflowId: &workflowID,
+		WorkflowType: &shared.WorkflowType{
+			Name: &workflowType,
+		},
+		TaskList: &shared.TaskList{
+			Name: &tasklist,
+		},
+		Input:                               input,
+		ExecutionStartToCloseTimeoutSeconds: &executionTimeout,
+		TaskStartToCloseTimeoutSeconds:      &closeTimeout,
+		RequestId:                           &requestID,
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
+	defer cancel()
+	resp, err := cadenceClient.StartWorkflowExecution(ctx, &req)
+	if err != nil {
+		logger.Error("Failed to create workflow", zap.Error(err))
+		panic("Failed to create workflow.")
+	}
+
+	logger.Info("successfully started HelloWorld workflow", zap.String("runID", resp.GetRunId()))
+}
+
+func withTLSDialOption() (grpc.DialOption, error) {
+	// Present client cert for mutual TLS (if enabled on server)
+	clientCert, err := tls.LoadX509KeyPair("credentials/client.crt", "credentials/client.key")
+	if err != nil {
+		return nil, fmt.Errorf("Failed to load client certificate: %v", zap.Error(err))
+	}
+
+	// Load server CA
+	caCert, err := os.ReadFile("credentials/keytest.crt")
+	if err != nil {
+		return nil, fmt.Errorf("Failed to load server CA certificate: %v", zap.Error(err))
+	}
+	caCertPool := x509.NewCertPool()
+	caCertPool.AppendCertsFromPEM(caCert)
+	tlsConfig := tls.Config{
+		InsecureSkipVerify: true,
+		RootCAs:            caCertPool,
+		Certificates:       []tls.Certificate{clientCert},
+	}
+	creds := credentials.NewTLS(&tlsConfig)
+	grpc.DialerCredentials(creds)
+	return grpc.DialerCredentials(creds), nil
+}

new_samples/client_samples/helloworld_tls/register_domain.go

@@ -0,0 +1,88 @@
+package main
+
+import (
+	"context"
+	"crypto/tls"
+	"crypto/x509"
+	"fmt"
+	"os"
+	"time"
+
+	"github.com/uber-common/cadence-samples/new_samples/worker"
+	"go.uber.org/cadence/.gen/go/shared"
+	"go.uber.org/yarpc/transport/grpc"
+	"go.uber.org/zap"
+	"google.golang.org/grpc/credentials"
+)
+
+func main() {
+	logger := worker.BuildLogger()
+	logger.Info("Registering default domain for cadence-vishwa with TLS...")
+
+	withTLSDialOption, err := buildTLSDialOption()
+	if err != nil {
+		logger.Fatal("Failed to build TLS dial option", zap.Error(err))
+	}
+
+	cadenceClient := worker.BuildCadenceClient(withTLSDialOption)
+
+	// Register the domain
+	domain := "default"
+	retentionDays := int32(7)
+	emitMetric := true
+
+	req := &shared.RegisterDomainRequest{
+		Name:                                   &domain,
+		Description:                            stringPtr("Default domain for cadence samples"),
+		WorkflowExecutionRetentionPeriodInDays: &retentionDays,
+		EmitMetric:                             &emitMetric,
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+
+	err = cadenceClient.RegisterDomain(ctx, req)
+	if err != nil {
+		// Check if domain already exists
+		if _, ok := err.(*shared.DomainAlreadyExistsError); ok {
+			logger.Info("Domain already exists", zap.String("domain", domain))
+			return
+		}
+		logger.Fatal("Failed to register domain", zap.Error(err))
+	}
+
+	logger.Info("Successfully registered domain", zap.String("domain", domain))
+}
+
+func buildTLSDialOption() (grpc.DialOption, error) {
+	// Load client certificate
+	clientCert, err := tls.LoadX509KeyPair("credentials/client.crt", "credentials/client.key")
+	if err != nil {
+		return nil, fmt.Errorf("failed to load client certificate: %w", err)
+	}
+
+	// Load server CA
+	caCert, err := os.ReadFile("credentials/keytest.crt")
+	if err != nil {
+		return nil, fmt.Errorf("failed to load server CA certificate: %w", err)
+	}
+
+	caCertPool := x509.NewCertPool()
+	if !caCertPool.AppendCertsFromPEM(caCert) {
+		return nil, fmt.Errorf("failed to append CA certificate")
+	}
+
+	tlsConfig := &tls.Config{
+		InsecureSkipVerify: true,
+		RootCAs:            caCertPool,
+		Certificates:       []tls.Certificate{clientCert},
+		MinVersion:         tls.VersionTLS12,
+	}
+
+	creds := credentials.NewTLS(tlsConfig)
+	return grpc.DialerCredentials(creds), nil
+}
+
+func stringPtr(s string) *string {
+	return &s
+}

new_samples/worker/worker.go

@@ -11,6 +11,8 @@ import (
 	"go.uber.org/cadence/worker"
 	"go.uber.org/cadence/workflow"
 	"go.uber.org/yarpc"
+	"go.uber.org/yarpc/peer"
+	yarpchostport "go.uber.org/yarpc/peer/hostport"
 	"go.uber.org/yarpc/transport/grpc"
 	"go.uber.org/zap"
 	"go.uber.org/zap/zapcore"
@@ -69,11 +71,18 @@ func StartWorker() {
 
 }
 
-func BuildCadenceClient() workflowserviceclient.Interface {
+func BuildCadenceClient(dialOptions ...grpc.DialOption) workflowserviceclient.Interface {
+	grpcTransport := grpc.NewTransport()
+	myChooser := peer.NewSingle(
+		yarpchostport.Identify(HostPort),
+		grpcTransport.NewDialer(dialOptions...),
+	)
+	outbound := grpcTransport.NewOutbound(myChooser)
+
 	dispatcher := yarpc.NewDispatcher(yarpc.Config{
 		Name: ClientName,
 		Outbounds: yarpc.Outbounds{
-			CadenceService: {Unary: grpc.NewTransport().NewSingleOutbound(HostPort)},
+			CadenceService: {Unary: outbound},
 		},
 	})
 	if err := dispatcher.Start(); err != nil {