Add Temporal Cloud OpenMetrics Prometheus+Grafana demo with scenario workflows

core/src/main/java/io/temporal/samples/temporalcloudopenmetrics/README.md

@@ -0,0 +1,102 @@
+# Temporal Cloud OpenMetrics → Prometheus → Grafana (Step-by-step)
+
+This demo shows how to **scrape Temporal Cloud OpenMetrics(https://docs.temporal.io/cloud/metrics/openmetrics/)** 
+with **Prometheus** and **visualize them in Grafana**.
+
+It uses the Grafana Temporal mixin dashboard template:
+https://github.com/grafana/jsonnet-libs/blob/master/temporal-mixin/dashboards/temporal-overview.json
+
+Once imported/provisioned, the dashboard lets you view the key Temporal metrics in a ready-made layout.
+
+Grafana dashboard view :-
+![Grafana dashboard 1](docs/images/img1.png)
+![Grafana dashboard 2](docs/images/img2.png)
+
+Prometheus -
+
+![Prometheus](docs/images/img3.png)
+
+---
+
+## 1) Create Service Account + API Key (Temporal Cloud)
+
+OpenMetrics auth reference:
+https://docs.temporal.io/production-deployment/cloud/metrics/openmetrics/api-reference#authentication
+
+In Temporal Cloud UI:
+- **Settings → Service Accounts**
+- Create a service account with **Metrics Read-Only** role
+- Generate an **API key** ( copy this, it will be needed later)
+---
+
+
+## 2) Create the `secrets/` folder + API key file
+
+From the repo root (same folder as `docker-compose.yml`), run:
+
+```
+cd temporalcloudopenmetrics
+mkdir -p secrets
+echo "put your CLOUD API KEY HERE" > secrets/temporal_cloud_api_key
+```
+now the folder will look like below and temporal_cloud_api_key will have the above api key that we generated in step 1
+
+```
+temporalcloudopenmetrics/
+├── docker-compose.yml
+├── prometheus/
+├── grafana/
+├── secrets/
+│   └── temporal_cloud_api_key
+```
+
+## 3) Configure TemporalConnection.java
+
+Edit `TemporalConnection.java` and set your defaults:
+
+```
+public static final String NAMESPACE = env("TEMPORAL_NAMESPACE", "<namespace>.<account-id>");
+public static final String ADDRESS   = env("TEMPORAL_ADDRESS", "<namespace>.<account-id>.tmprl.cloud:7233");
+public static final String CERT      = env("TEMPORAL_CERT", "/path/to/client.pem");
+public static final String KEY       = env("TEMPORAL_KEY",  "/path/to/client.key");
+public static final String TASK_QUEUE = env("TASK_QUEUE", "openmetrics-task-queue");
+public static final int WORKER_SECONDS = envInt("WORKER_SECONDS", 60);
+```
+
+## 4) 4) Update Prometheus scrape config
+
+prometheus/config.yml
+Update it to use your namespace
+```
+    params:
+      namespaces: [ '<namespace>.<account-id>' ]
+```
+
+
+## 5) Start Prometheus + Grafana
+
+docker compose up -d
+docker compose ps
+
+
+## 6) View Grafana dashboard
+
+http://localhost:3001/
+
+- Username: admin
+- Password: admin
+
+You should see the Temporal Cloud OpenMetrics dashboard.
+
+## 7) Verify metrics in Prometheus
+
+Prometheus: http://localhost:9093/
+
+Go to:
+Status → Targets (make sure the scrape target is UP)
+Graph tab (search for Temporal metrics and run a query)
+
+## 8) Ran the sample and view the cloud metrics 
+
+- `./gradlew -q execute -PmainClass=io.temporal.samples.temporalcloudopenmetrics.WorkerMain`
+- `./gradlew -q execute -PmainClass=io.temporal.samples.temporalcloudopenmetrics.Starter`

core/src/main/java/io/temporal/samples/temporalcloudopenmetrics/Starter.java

@@ -0,0 +1,54 @@
+package io.temporal.samples.temporalcloudopenmetrics;
+
+import io.temporal.client.WorkflowClient;
+import io.temporal.client.WorkflowOptions;
+import io.temporal.client.WorkflowStub;
+import io.temporal.samples.temporalcloudopenmetrics.workflows.ScenarioWorkflow;
+import java.time.Duration;
+import java.util.UUID;
+
+public class Starter {
+
+  public static void main(String[] args) throws Exception {
+    WorkflowClient client = TemporalConnection.client();
+
+    String name = "Temporal";
+    String[] scenarios = {"success", "fail", "timeout", "continue", "cancel"};
+
+    for (String scenario : scenarios) {
+      String wid = "scenario-" + scenario + "-" + UUID.randomUUID();
+
+      WorkflowOptions.Builder optionsBuilder =
+          WorkflowOptions.newBuilder()
+              .setTaskQueue(TemporalConnection.TASK_QUEUE)
+              .setWorkflowId(wid);
+
+      // workflow timeout
+      if ("timeout".equalsIgnoreCase(scenario)) {
+        optionsBuilder.setWorkflowRunTimeout(Duration.ofSeconds(3));
+      }
+
+      ScenarioWorkflow wf = client.newWorkflowStub(ScenarioWorkflow.class, optionsBuilder.build());
+
+      System.out.println("\n=== Starting scenario: " + scenario + " workflowId=" + wid + " ===");
+
+      try {
+        if ("cancel".equalsIgnoreCase(scenario)) {
+          WorkflowClient.start(wf::run, scenario, name);
+          Thread.sleep(2000);
+          WorkflowStub untyped = client.newUntypedWorkflowStub(wid);
+          untyped.cancel();
+          untyped.getResult(String.class);
+          continue;
+        }
+
+        // normal synchronous execution
+        String result = wf.run(scenario, name);
+        System.out.println("Scenario=" + scenario + " Result=" + result);
+
+      } catch (Exception e) {
+        System.out.println("Scenario=" + scenario + " ended: " + e.getClass().getSimpleName() + " - " + e.getMessage());
+      }
+    }
+  }
+}

core/src/main/java/io/temporal/samples/temporalcloudopenmetrics/TemporalConnection.java

@@ -0,0 +1,74 @@
+package io.temporal.samples.temporalcloudopenmetrics;
+
+import io.grpc.netty.shaded.io.grpc.netty.GrpcSslContexts;
+import io.grpc.netty.shaded.io.netty.handler.ssl.SslContext;
+import io.grpc.netty.shaded.io.netty.handler.ssl.SslContextBuilder;
+import io.temporal.client.WorkflowClient;
+import io.temporal.client.WorkflowClientOptions;
+import io.temporal.serviceclient.WorkflowServiceStubs;
+import io.temporal.serviceclient.WorkflowServiceStubsOptions;
+import java.io.FileInputStream;
+import java.io.InputStream;
+
+public final class TemporalConnection {
+  private TemporalConnection() {}
+
+  // add your namespace here
+  public static final String NAMESPACE = env("TEMPORAL_NAMESPACE", "deepika-test-namespace.a2dd6");
+
+  public static final String ADDRESS =
+      env("TEMPORAL_ADDRESS", "deepika-test-namespace.a2dd6.tmprl.cloud:7233");
+
+  public static final String CERT =
+      env("TEMPORAL_CERT", "/Users/deepikaawasthi/temporal/temporal-certs/client.pem");
+
+  public static final String KEY =
+      env("TEMPORAL_KEY", "/Users/deepikaawasthi/temporal/temporal-certs/client.key");
+
+  public static final String TASK_QUEUE = env("TASK_QUEUE", "openmetrics-task-queue");
+
+  // default 60s; override with WORKER_SECONDS env var
+  public static final int WORKER_SECONDS = envInt("WORKER_SECONDS", 60);
+
+  public static WorkflowClient client() {
+    WorkflowServiceStubs service = serviceStubs();
+    return WorkflowClient.newInstance(
+        service, WorkflowClientOptions.newBuilder().setNamespace(NAMESPACE).build());
+  }
+
+  // this will create servicestubs and which will be used by both workermain and starter
+  private static WorkflowServiceStubs serviceStubs() {
+    try (InputStream clientCert = new FileInputStream(CERT);
+        InputStream clientKey = new FileInputStream(KEY)) {
+
+      SslContext sslContext =
+          GrpcSslContexts.configure(SslContextBuilder.forClient().keyManager(clientCert, clientKey))
+              .build();
+
+      WorkflowServiceStubsOptions options =
+          WorkflowServiceStubsOptions.newBuilder()
+              .setTarget(ADDRESS)
+              .setSslContext(sslContext)
+              .build();
+
+      return WorkflowServiceStubs.newServiceStubs(options);
+    } catch (Exception e) {
+      throw new RuntimeException("Failed to create Temporal TLS connection", e);
+    }
+  }
+
+  private static String env(String key, String def) {
+    String v = System.getenv(key);
+    return (v == null || v.isBlank()) ? def : v;
+  }
+
+  private static int envInt(String key, int def) {
+    String v = System.getenv(key);
+    if (v == null || v.isBlank()) return def;
+    try {
+      return Integer.parseInt(v.trim());
+    } catch (Exception e) {
+      return def;
+    }
+  }
+}

core/src/main/java/io/temporal/samples/temporalcloudopenmetrics/WorkerMain.java

@@ -0,0 +1,30 @@
+package io.temporal.samples.temporalcloudopenmetrics;
+
+import io.temporal.client.WorkflowClient;
+import io.temporal.samples.temporalcloudopenmetrics.activities.ScenarioActivitiesImpl;
+import io.temporal.samples.temporalcloudopenmetrics.workflows.ScenarioWorkflowImpl;
+import io.temporal.worker.WorkerFactory;
+
+public class WorkerMain {
+  public static void main(String[] args) throws Exception {
+    WorkflowClient client = TemporalConnection.client();
+
+    WorkerFactory factory = WorkerFactory.newInstance(client);
+    io.temporal.worker.Worker worker = factory.newWorker(TemporalConnection.TASK_QUEUE);
+
+    worker.registerWorkflowImplementationTypes(ScenarioWorkflowImpl.class);
+    worker.registerActivitiesImplementations(new ScenarioActivitiesImpl());
+
+    factory.start();
+    System.out.println(
+        "Worker started. namespace="
+            + TemporalConnection.NAMESPACE
+            + " taskQueue="
+            + TemporalConnection.TASK_QUEUE);
+
+    Thread.sleep(TemporalConnection.WORKER_SECONDS * 1000L);
+
+    System.out.println("Stopping worker after " + TemporalConnection.WORKER_SECONDS + "s");
+    factory.shutdown();
+  }
+}

core/src/main/java/io/temporal/samples/temporalcloudopenmetrics/activities/ScenarioActivities.java

@@ -0,0 +1,10 @@
+package io.temporal.samples.temporalcloudopenmetrics.activities;
+
+import io.temporal.activity.ActivityInterface;
+import io.temporal.activity.ActivityMethod;
+
+@ActivityInterface
+public interface ScenarioActivities {
+  @ActivityMethod
+  String doWork(String name, String scenario);
+}

core/src/main/java/io/temporal/samples/temporalcloudopenmetrics/activities/ScenarioActivitiesImpl.java

@@ -0,0 +1,39 @@
+package io.temporal.samples.temporalcloudopenmetrics.activities;
+
+import io.temporal.activity.Activity;
+import io.temporal.failure.ApplicationFailure;
+
+public class ScenarioActivitiesImpl implements ScenarioActivities {
+
+  @Override
+  public String doWork(String name, String scenario) {
+    if ("fail".equalsIgnoreCase(scenario)) {
+      throw ApplicationFailure.newNonRetryableFailure(
+          "Intentional failure for dashboard", "SCENARIO_FAIL");
+    }
+
+    if ("timeout".equalsIgnoreCase(scenario)) {
+      sleepMs(5_000);
+      return "unreachable (should have timed out)";
+    }
+
+    if ("cancel".equalsIgnoreCase(scenario)) {
+      while (true) {
+        Activity.getExecutionContext().heartbeat("still-running");
+        sleepMs(1_000);
+      }
+    }
+
+    // success
+    return "Hello " + name;
+  }
+
+  private static void sleepMs(long ms) {
+    try {
+      Thread.sleep(ms);
+    } catch (InterruptedException e) {
+      Thread.currentThread().interrupt();
+      throw new RuntimeException("Interrupted", e);
+    }
+  }
+}

core/src/main/java/io/temporal/samples/temporalcloudopenmetrics/docker-compose.yml

@@ -0,0 +1,37 @@
+services:
+  grafana:
+    image: grafana/grafana:latest
+    ports:
+      - "3001:3000"
+    depends_on:
+      - prometheus
+    networks:
+      - temporal_network
+    volumes:
+      - ./grafana/provisioning:/etc/grafana/provisioning:ro
+      - ./grafana/dashboards:/var/lib/grafana/dashboards:ro
+
+
+  prometheus:
+    container_name: prometheus
+    image: prom/prometheus:v2.37.0
+    command:
+      - --web.enable-remote-write-receiver
+      - --config.file=/etc/prometheus/prometheus.yml
+    ports:
+      - "9093:9090"   # host port changed to avoid conflicts
+    volumes:
+      - type: bind
+        source: ./prometheus/config.yml
+        target: /etc/prometheus/prometheus.yml
+      - type: bind
+        source: ./secrets/temporal_cloud_api_key
+        target: /etc/prometheus/temporal_cloud_api_key
+        read_only: true
+    networks:
+      - temporal_network
+
+networks:
+  temporal_network:
+    driver: bridge
+    name: temporal_network