Add Nexus sample

build.gradle

@@ -28,7 +28,7 @@ subprojects {
     ext {
         otelVersion = '1.30.1'
         otelVersionAlpha = "${otelVersion}-alpha"
-        javaSDKVersion = '1.25.0'
+        javaSDKVersion = '1.26.0'
         camelVersion = '3.22.1'
         jarVersion = '1.0.0'
     }

core/build.gradle

@@ -28,6 +28,7 @@ dependencies {
     implementation group: 'io.cloudevents', name: 'cloudevents-api', version: '4.0.1'
     implementation group: 'io.cloudevents', name: 'cloudevents-json-jackson', version: '3.0.0'
     implementation group: 'net.thisptr', name: 'jackson-jq', version: '1.0.0-preview.20240207'
+    implementation group: 'commons-cli', name: 'commons-cli', version: '1.9.0'
 
     // we don't update it to 2.1.0 because 2.1.0 requires Java 11
     implementation 'com.codingrodent:jackson-json-crypto:1.1.0'

core/src/main/java/io/temporal/samples/nexus/README.MD

@@ -0,0 +1,103 @@
+# Nexus
+
+Temporal Nexus is a new feature of the Temporal platform designed to connect durable executions across team, namespace,
+region, and cloud boundaries. It promotes a more modular architecture for sharing a subset of your team’s capabilities
+via well-defined service API contracts for other teams to use, that abstract underlying Temporal primitives, like
+Workflows, or execute arbitrary code.
+
+Learn more at [temporal.io/nexus](https://temporal.io/nexus).
+
+This sample shows how to use Temporal for authoring a Nexus service and call it from a workflow.
+
+### Sample directory structure
+
+- [service](./service) - shared service definition
+- [caller](./caller) - caller workflows, worker, and starter
+- [handler](./handler) - handler workflow, operations, and worker
+- [options](./options) - command line argument parsing utility
+
+## Getting started locally
+
+### Get `temporal` CLI to enable local development
+
+1. Follow the instructions on the [docs
+   site](https://learn.temporal.io/getting_started/go/dev_environment/#set-up-a-local-temporal-service-for-development-with-temporal-cli)
+   to install Temporal CLI.
+
+> NOTE: Required version is at least v1.1.0.
+
+### Spin up environment
+
+#### Start temporal server
+
+> HTTP port is required for Nexus communications
+
+```
+temporal server start-dev --http-port 7243 --dynamic-config-value system.enableNexus=true
+```
+
+### Initialize environment
+
+In a separate terminal window
+
+#### Create caller and target namespaces
+
+```
+temporal operator namespace create --namespace my-target-namespace
+temporal operator namespace create --namespace my-caller-namespace
+```
+
+#### Create Nexus endpoint
+
+```
+temporal operator nexus endpoint create \
+  --name my-nexus-endpoint-name \
+  --target-namespace my-target-namespace \
+  --target-task-queue my-handler-task-queue \
+  --description-file ./service/description.md
+```
+
+## Getting started with a self-hosted service or Temporal Cloud
+
+Nexus is currently available as
+[Public Preview](https://docs.temporal.io/evaluate/development-production-features/release-stages).
+
+Self hosted users can [try Nexus
+out](https://github.com/temporalio/temporal/blob/main/docs/architecture/nexus.md#trying-nexus-out) in single cluster
+deployments with server version 1.25.0.
+
+### Make Nexus calls across namespace boundaries
+
+> Instructions apply for local development, for Temporal Cloud or a self-hosted setups, supply the relevant [CLI
+> flags](./options/ClientOptions.java) to properly set up the connection.
+
+In separate terminal windows:
+
+### Nexus handler worker
+
+```
+./gradlew -q execute -PmainClass=io.temporal.samples.nexus.handler.HandlerWorker \
+    --args="-target-host localhost:7233 -namespace my-target-namespace"
+```
+
+### Nexus caller worker
+
+```
+./gradlew -q execute -PmainClass=io.temporal.samples.nexus.caller.CallerWorker \
+    --args="-target-host localhost:7233 -namespace my-caller-namespace"
+```
+
+### Start caller workflow
+
+```
+./gradlew -q execute -PmainClass=io.temporal.samples.nexus.caller.CallerStarter \
+    --args="-target-host localhost:7233 -namespace my-caller-namespace"
+```
+
+### Output
+
+which should result in:
+```
+[main] INFO  i.t.s.nexus.caller.CallerStarter - Workflow result: Nexus Echo 👋 
+[main] INFO  i.t.s.nexus.caller.CallerStarter - Workflow result: ¡Hola! Nexus 👋  
+```

core/src/main/java/io/temporal/samples/nexus/caller/CallerStarter.java

@@ -0,0 +1,53 @@
+/*
+ *  Copyright (c) 2020 Temporal Technologies, Inc. All Rights Reserved
+ *
+ *  Copyright 2012-2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ *  Modifications copyright (C) 2017 Uber Technologies, Inc.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"). You may not
+ *  use this file except in compliance with the License. A copy of the License is
+ *  located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ *  or in the "license" file accompanying this file. This file is distributed on
+ *  an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ *  express or implied. See the License for the specific language governing
+ *  permissions and limitations under the License.
+ */
+
+package io.temporal.samples.nexus.caller;
+
+import io.temporal.client.WorkflowClient;
+import io.temporal.client.WorkflowOptions;
+import io.temporal.client.WorkflowStub;
+import io.temporal.samples.nexus.options.ClientOptions;
+import io.temporal.samples.nexus.service.NexusService;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class CallerStarter {
+  private static final Logger logger = LoggerFactory.getLogger(CallerStarter.class);
+
+  public static void main(String[] args) {
+    WorkflowClient client = ClientOptions.getWorkflowClient(args);
+
+    WorkflowOptions workflowOptions =
+        WorkflowOptions.newBuilder().setTaskQueue(CallerWorker.DEFAULT_TASK_QUEUE_NAME).build();
+    EchoCallerWorkflow echoWorkflow =
+        client.newWorkflowStub(EchoCallerWorkflow.class, workflowOptions);
+    logger.info("Workflow result: {}", echoWorkflow.echo("Nexus Echo 👋"));
+    logger.info(
+        "Started workflow workflowId: {} runId: {}",
+        WorkflowStub.fromTyped(echoWorkflow).getExecution().getWorkflowId(),
+        WorkflowStub.fromTyped(echoWorkflow).getExecution().getRunId());
+    HelloCallerWorkflow helloWorkflow =
+        client.newWorkflowStub(HelloCallerWorkflow.class, workflowOptions);
+    logger.info("Workflow result: {}", helloWorkflow.hello("Nexus", NexusService.Language.ES));
+    logger.info(
+        "Started workflow workflowId: {} runId: {}",
+        WorkflowStub.fromTyped(helloWorkflow).getExecution().getWorkflowId(),
+        WorkflowStub.fromTyped(helloWorkflow).getExecution().getRunId());
+  }
+}

core/src/main/java/io/temporal/samples/nexus/caller/CallerWorker.java

@@ -0,0 +1,51 @@
+/*
+ *  Copyright (c) 2020 Temporal Technologies, Inc. All Rights Reserved
+ *
+ *  Copyright 2012-2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ *  Modifications copyright (C) 2017 Uber Technologies, Inc.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"). You may not
+ *  use this file except in compliance with the License. A copy of the License is
+ *  located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ *  or in the "license" file accompanying this file. This file is distributed on
+ *  an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ *  express or implied. See the License for the specific language governing
+ *  permissions and limitations under the License.
+ */
+
+package io.temporal.samples.nexus.caller;
+
+import io.temporal.client.WorkflowClient;
+import io.temporal.samples.nexus.options.ClientOptions;
+import io.temporal.worker.Worker;
+import io.temporal.worker.WorkerFactory;
+import io.temporal.worker.WorkflowImplementationOptions;
+import io.temporal.workflow.NexusServiceOptions;
+import java.util.Collections;
+
+public class CallerWorker {
+  public static final String DEFAULT_TASK_QUEUE_NAME = "my-caller-workflow-task-queue";
+
+  public static void main(String[] args) {
+    WorkflowClient client = ClientOptions.getWorkflowClient(args);
+
+    WorkerFactory factory = WorkerFactory.newInstance(client);
+
+    Worker worker = factory.newWorker(DEFAULT_TASK_QUEUE_NAME);
+    worker.registerWorkflowImplementationTypes(
+        WorkflowImplementationOptions.newBuilder()
+            .setNexusServiceOptions(
+                Collections.singletonMap(
+                    "NexusService",
+                    NexusServiceOptions.newBuilder().setEndpoint("my-nexus-endpoint-name").build()))
+            .build(),
+        EchoCallerWorkflowImpl.class,
+        HelloCallerWorkflowImpl.class);
+
+    factory.start();
+  }
+}

core/src/main/java/io/temporal/samples/nexus/caller/EchoCallerWorkflow.java

@@ -0,0 +1,29 @@
+/*
+ *  Copyright (c) 2020 Temporal Technologies, Inc. All Rights Reserved
+ *
+ *  Copyright 2012-2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ *  Modifications copyright (C) 2017 Uber Technologies, Inc.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"). You may not
+ *  use this file except in compliance with the License. A copy of the License is
+ *  located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ *  or in the "license" file accompanying this file. This file is distributed on
+ *  an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ *  express or implied. See the License for the specific language governing
+ *  permissions and limitations under the License.
+ */
+
+package io.temporal.samples.nexus.caller;
+
+import io.temporal.workflow.WorkflowInterface;
+import io.temporal.workflow.WorkflowMethod;
+
+@WorkflowInterface
+public interface EchoCallerWorkflow {
+  @WorkflowMethod
+  String echo(String message);
+}

core/src/main/java/io/temporal/samples/nexus/caller/EchoCallerWorkflowImpl.java

@@ -0,0 +1,43 @@
+/*
+ *  Copyright (c) 2020 Temporal Technologies, Inc. All Rights Reserved
+ *
+ *  Copyright 2012-2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ *  Modifications copyright (C) 2017 Uber Technologies, Inc.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"). You may not
+ *  use this file except in compliance with the License. A copy of the License is
+ *  located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ *  or in the "license" file accompanying this file. This file is distributed on
+ *  an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ *  express or implied. See the License for the specific language governing
+ *  permissions and limitations under the License.
+ */
+
+package io.temporal.samples.nexus.caller;
+
+import io.temporal.samples.nexus.service.NexusService;
+import io.temporal.workflow.NexusOperationOptions;
+import io.temporal.workflow.NexusServiceOptions;
+import io.temporal.workflow.Workflow;
+import java.time.Duration;
+
+public class EchoCallerWorkflowImpl implements EchoCallerWorkflow {
+  NexusService nexusService =
+      Workflow.newNexusServiceStub(
+          NexusService.class,
+          NexusServiceOptions.newBuilder()
+              .setOperationOptions(
+                  NexusOperationOptions.newBuilder()
+                      .setScheduleToCloseTimeout(Duration.ofSeconds(10))
+                      .build())
+              .build());
+
+  @Override
+  public String echo(String message) {
+    return nexusService.echo(new NexusService.EchoInput(message)).getMessage();
+  }
+}

core/src/main/java/io/temporal/samples/nexus/caller/HelloCallerWorkflow.java

@@ -0,0 +1,30 @@
+/*
+ *  Copyright (c) 2020 Temporal Technologies, Inc. All Rights Reserved
+ *
+ *  Copyright 2012-2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ *  Modifications copyright (C) 2017 Uber Technologies, Inc.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"). You may not
+ *  use this file except in compliance with the License. A copy of the License is
+ *  located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ *  or in the "license" file accompanying this file. This file is distributed on
+ *  an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ *  express or implied. See the License for the specific language governing
+ *  permissions and limitations under the License.
+ */
+
+package io.temporal.samples.nexus.caller;
+
+import io.temporal.samples.nexus.service.NexusService;
+import io.temporal.workflow.WorkflowInterface;
+import io.temporal.workflow.WorkflowMethod;
+
+@WorkflowInterface
+public interface HelloCallerWorkflow {
+  @WorkflowMethod
+  String hello(String message, NexusService.Language language);
+}

core/src/main/java/io/temporal/samples/nexus/caller/HelloCallerWorkflowImpl.java

@@ -0,0 +1,50 @@
+/*
+ *  Copyright (c) 2020 Temporal Technologies, Inc. All Rights Reserved
+ *
+ *  Copyright 2012-2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ *  Modifications copyright (C) 2017 Uber Technologies, Inc.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"). You may not
+ *  use this file except in compliance with the License. A copy of the License is
+ *  located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ *  or in the "license" file accompanying this file. This file is distributed on
+ *  an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ *  express or implied. See the License for the specific language governing
+ *  permissions and limitations under the License.
+ */
+
+package io.temporal.samples.nexus.caller;
+
+import io.temporal.samples.nexus.service.NexusService;
+import io.temporal.workflow.NexusOperationHandle;
+import io.temporal.workflow.NexusOperationOptions;
+import io.temporal.workflow.NexusServiceOptions;
+import io.temporal.workflow.Workflow;
+import java.time.Duration;
+
+public class HelloCallerWorkflowImpl implements HelloCallerWorkflow {
+  NexusService nexusService =
+      Workflow.newNexusServiceStub(
+          NexusService.class,
+          NexusServiceOptions.newBuilder()
+              .setOperationOptions(
+                  NexusOperationOptions.newBuilder()
+                      .setScheduleToCloseTimeout(Duration.ofSeconds(10))
+                      .build())
+              .build());
+
+  @Override
+  public String hello(String message, NexusService.Language language) {
+    NexusOperationHandle<NexusService.HelloOutput> handle =
+        Workflow.startNexusOperation(
+            nexusService::hello, new NexusService.HelloInput(message, language));
+    // Optionally wait for the operation to be started. NexusOperationExecution will contain the
+    // operation ID in case this operation is asynchronous.
+    handle.getExecution().get();
+    return handle.getResult().get().getMessage();
+  }
+}