# Cadence® Connection Examples Using TLS [Blog](/blog/)>[Technology](/blog/category/technical/)>Cadence® Connection Examples Using TLS Cadence® Connection Examples Using TLS ====================================== December 02, 2022 | By [ Rony Rahman](https://www.instaclustr.com/blog/author/rony-rahman/) [ ](https://x.com/intent/tweet?text=Cadence%C2%AE%20Connection%20Examples%20Using%20TLS&url=https://www.instaclustr.com/blog/cadence-connection-examples-using-tls/) [ ](https://www.linkedin.com/shareArticle?mini=true&url=https://www.instaclustr.com/blog/cadence-connection-examples-using-tls/&title=&summary=Cadence%C2%AE%20Connection%20Examples%20Using%20TLS&source=) In Cadence® 0.24.0, TLS support was introduced for the gRPC transport (). In this blog we provide a couple of sample code snippets—one using the Go SDK and the other using the Java SDK—to demonstrate how to establish connection to the Cadence server using TLS. For both the snippets, we assume a X.509 Certificate Authority (CA) certificate from the Cadence server in PEM-encoded (ASCII) format called ***ca-certificate.pem***. ### **Go** To create a **Worker** using Go, the following code snippet can be used: package main import ( "fmt" "github.com/uber-go/tally" apiv1 "github.com/uber/cadence-idl/go/proto/api/v1" "go.uber.org/cadence/.gen/go/cadence/workflowserviceclient" "go.uber.org/cadence/compatibility" "go.uber.org/cadence/worker" "go.uber.org/yarpc" "go.uber.org/yarpc/transport/grpc" "go.uber.org/zap" "go.uber.org/zap/zapcore" "crypto/tls" "crypto/x509" "io/ioutil" "go.uber.org/yarpc/peer" "go.uber.org/yarpc/peer/hostport" "google.golang.org/grpc/credentials" ) var HostPort = "<HOST>:<PORT>" var Domain = "<DOMAIN>" var TaskListName = "<TASK>" var ClientName = "<CLIENT>" var CadenceService = "cadence-frontend" func main() { ………………… ………………… ………………… worker := getWorker(buildLogger(), buildCadenceClient()) ………………… ………………… ………………… } func buildLogger() \*zap.Logger { config := zap.NewDevelopmentConfig() config.Level.SetLevel(zapcore.InfoLevel) var err error logger, err := config.Build() if err != nil { panic("Failed to setup logger") } return logger } func buildCadenceClient() workflowserviceclient.Interface { grpcTransport := grpc.NewTransport() var dialOptions \[\]grpc.DialOption caCert, err := ioutil.ReadFile("ca-certificate.pem") if err != nil { fmt.Printf("Failed to load server CA certificate: %v", zap.Error(err)) } caCertPool := x509.NewCertPool() if !caCertPool.AppendCertsFromPEM(caCert) { fmt.Errorf("Failed to add server CA's certificate") } tlsConfig := tls.Config{ RootCAs: caCertPool, } creds := credentials.NewTLS(&tlsConfig) dialOptions = append(dialOptions, grpc.DialerCredentials(creds)) dialer := grpcTransport.NewDialer(dialOptions...) outbound := grpcTransport.NewOutbound( peer.NewSingle(hostport.PeerIdentifier(HostPort), dialer) ) dispatcher := yarpc.NewDispatcher(yarpc.Config{ Name: ClientName, Outbounds: yarpc.Outbounds{ CadenceService: {Unary: outbound}, }, }) if err := dispatcher.Start(); err != nil { panic("Failed to start dispatcher") } clientConfig := dispatcher.ClientConfig(CadenceService) return compatibility.NewThrift2ProtoAdapter( apiv1.NewDomainAPIYARPCClient(clientConfig), apiv1.NewWorkflowAPIYARPCClient(clientConfig), apiv1.NewWorkerAPIYARPCClient(clientConfig), apiv1.NewVisibilityAPIYARPCClient(clientConfig), ) } func getWorker(logger \*zap.Logger, service workflowserviceclient.Interface) worker.Worker { workerOptions := worker.Options{ Logger: logger, MetricsScope: tally.NewTestScope(TaskListName, map\[string\]string{}), } worker := worker.New( service, Domain, TaskListName, workerOptions) return worker } 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 package main import ( "fmt" "github.com/uber-go/tally" apiv1 "github.com/uber/cadence-idl/go/proto/api/v1" "go.uber.org/cadence/.gen/go/cadence/workflowserviceclient" "go.uber.org/cadence/compatibility" "go.uber.org/cadence/worker" "go.uber.org/yarpc" "go.uber.org/yarpc/transport/grpc" "go.uber.org/zap" "go.uber.org/zap/zapcore" "crypto/tls" "crypto/x509" "io/ioutil" "go.uber.org/yarpc/peer" "go.uber.org/yarpc/peer/hostport" "google.golang.org/grpc/credentials" ) var HostPort = "<HOST>:<PORT>" var Domain = "<DOMAIN>" var TaskListName = "<TASK>" var ClientName = "<CLIENT>" var CadenceService = "cadence-frontend" func main() { ………………… ………………… ………………… worker := getWorker(buildLogger(), buildCadenceClient()) ………………… ………………… ………………… } func buildLogger() \*zap.Logger { config := zap.NewDevelopmentConfig() config.Level.SetLevel(zapcore.InfoLevel) var err error logger, err := config.Build() if err != nil { panic("Failed to setup logger") } return logger } func buildCadenceClient() workflowserviceclient.Interface { grpcTransport := grpc.NewTransport() var dialOptions \[\]grpc.DialOption caCert, err := ioutil.ReadFile("ca-certificate.pem") if err != nil { fmt.Printf("Failed to load server CA certificate: %v", zap.Error(err)) } caCertPool := x509.NewCertPool() if !caCertPool.AppendCertsFromPEM(caCert) { fmt.Errorf("Failed to add server CA's certificate") } tlsConfig := tls.Config{ RootCAs: caCertPool, } creds := credentials.NewTLS(&tlsConfig) dialOptions = append(dialOptions, grpc.DialerCredentials(creds)) dialer := grpcTransport.NewDialer(dialOptions...) outbound := grpcTransport.NewOutbound( peer.NewSingle(hostport.PeerIdentifier(HostPort), dialer) ) dispatcher := yarpc.NewDispatcher(yarpc.Config{ Name: ClientName, Outbounds: yarpc.Outbounds{ CadenceService: {Unary: outbound}, }, }) if err := dispatcher.Start(); err != nil { panic("Failed to start dispatcher") } clientConfig := dispatcher.ClientConfig(CadenceService) return compatibility.NewThrift2ProtoAdapter( apiv1.NewDomainAPIYARPCClient(clientConfig), apiv1.NewWorkflowAPIYARPCClient(clientConfig), apiv1.NewWorkerAPIYARPCClient(clientConfig), apiv1.NewVisibilityAPIYARPCClient(clientConfig), ) } func getWorker(logger \*zap.Logger, service workflowserviceclient.Interface) worker.Worker { workerOptions := worker.Options{ Logger: logger, MetricsScope: tally.NewTestScope(TaskListName, map\[string\]string{}), } worker := worker.New( service, Domain, TaskListName, workerOptions) return worker } ### **Java** In order to use the Java SDK to establish a connection to the Cadence server over TLS, the following Maven dependencies are needed: <dependency> <groupId>io.grpc</groupId> <artifactId>grpc-netty</artifactId> <version>1.28.0</version> </dependency> <dependency> <groupId>com.uber.cadence</groupId> <artifactId>cadence-client</artifactId> <version>3.7.2</version> </dependency> <dependency> <groupId>io.netty</groupId> <artifactId>netty-all</artifactId> <version>4.1.17.Final</version> </dependency> 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 <dependency> <groupId>io.grpc</groupId> <artifactId>grpc-netty</artifactId> <version>1.28.0</version> </dependency> <dependency> <groupId>com.uber.cadence</groupId> <artifactId>cadence-client</artifactId> <version>3.7.2</version> </dependency> <dependency> <groupId>io.netty</groupId> <artifactId>netty-all</artifactId> <version>4.1.17.Final</version> </dependency> The following code snippet demonstrates how to create a new **Worker**. import com.uber.cadence.client.WorkflowClient; import com.uber.cadence.client.WorkflowClientOptions; import com.uber.cadence.internal.compatibility.Thrift2ProtoAdapter; import com.uber.cadence.internal.compatibility.proto.serviceclient.IGrpcServiceStubs; import com.uber.cadence.serviceclient.ClientOptions; import com.uber.cadence.worker.Worker; import com.uber.cadence.worker.WorkerFactory; import io.grpc.netty.GrpcSslContexts; import io.grpc.netty.NettyChannelBuilder; import java.io.File; …………………… …………………… …………………… WorkflowClient workflowClient = WorkflowClient.newInstance( new Thrift2ProtoAdapter( IGrpcServiceStubs.newInstance( ClientOptions.newBuilder() .setGRPCChannel( NettyChannelBuilder.forAddress("<HOST>", <PORT>) .useTransportSecurity() .defaultLoadBalancingPolicy("round\_robin") .sslContext(GrpcSslContexts.forClient() .trustManager(new File("ca-certificate.pem")) .build() ) .build() ) .build() ) ), WorkflowClientOptions.newBuilder() .setDomain("<DOMAIN>") .build() ); WorkerFactory factory = WorkerFactory.newInstance(workflowClient); Worker worker = factory.newWorker("<ACTIVITY>"); …………………… …………………… …………………… 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 import com.uber.cadence.client.WorkflowClient; import com.uber.cadence.client.WorkflowClientOptions; import com.uber.cadence.internal.compatibility.Thrift2ProtoAdapter; import com.uber.cadence.internal.compatibility.proto.serviceclient.IGrpcServiceStubs; import com.uber.cadence.serviceclient.ClientOptions; import com.uber.cadence.worker.Worker; import com.uber.cadence.worker.WorkerFactory; import io.grpc.netty.GrpcSslContexts; import io.grpc.netty.NettyChannelBuilder; import java.io.File; …………………… …………………… …………………… WorkflowClient workflowClient = WorkflowClient.newInstance( new Thrift2ProtoAdapter( IGrpcServiceStubs.newInstance( ClientOptions.newBuilder() .setGRPCChannel( NettyChannelBuilder.forAddress("<HOST>", <PORT>) .useTransportSecurity() .defaultLoadBalancingPolicy("round\_robin") .sslContext(GrpcSslContexts.forClient() .trustManager(new File("ca-certificate.pem")) .build() ) .build() ) .build() ) ), WorkflowClientOptions.newBuilder() .setDomain("<DOMAIN>") .build() ); WorkerFactory factory = WorkerFactory.newInstance(workflowClient); Worker worker = factory.newWorker("<ACTIVITY>"); …………………… …………………… …………………… ### About the author **[Rony Rahman](https://www.instaclustr.com/blog/author/rony-rahman/)** | Lead Software Engineer Rony is a Lead software engineer at Instaclustr. 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