use describeNamespace

Author: yuandrew

temporal-sdk/src/main/java/io/temporal/worker/WorkerFactory.java

@@ -4,6 +4,8 @@
 import com.google.common.base.Preconditions;
 import com.google.common.base.Strings;
 import com.uber.m3.tally.Scope;
+import io.temporal.api.workflowservice.v1.DescribeNamespaceRequest;
+import io.temporal.api.workflowservice.v1.DescribeNamespaceResponse;
 import io.temporal.client.WorkflowClient;
 import io.temporal.client.WorkflowClientOptions;
 import io.temporal.common.converter.DataConverter;
@@ -196,9 +198,14 @@ public synchronized void start() {
 
     // Workers check and require that Temporal Server is available during start to fail-fast in case
     // of configuration issues.
-    // TODO(https://github.com/temporalio/sdk-java/issues/2060) consider using describeNamespace as
-    // a connection check.
-    workflowClient.getWorkflowServiceStubs().getServerCapabilities();
+    DescribeNamespaceResponse response =
+        workflowClient
+            .getWorkflowServiceStubs()
+            .blockingStub()
+            .describeNamespace(
+                DescribeNamespaceRequest.newBuilder()
+                    .setNamespace(workflowClient.getOptions().getNamespace())
+                    .build());
 
     for (Worker worker : workers.values()) {
       worker.start();

temporal-sdk/src/test/java/io/temporal/workerFactory/WorkerFactoryTests.java

@@ -1,9 +1,14 @@
 package io.temporal.workerFactory;
 
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertThrows;
 import static org.junit.Assert.assertTrue;
 
+import io.grpc.Status;
+import io.grpc.StatusRuntimeException;
 import io.temporal.client.WorkflowClient;
+import io.temporal.client.WorkflowClientOptions;
 import io.temporal.serviceclient.WorkflowServiceStubs;
 import io.temporal.serviceclient.WorkflowServiceStubsOptions;
 import io.temporal.worker.WorkerFactory;
@@ -128,4 +133,24 @@ public void factoryCanBeShutdownMoreThanOnce() {
     factory.shutdown();
     factory.awaitTermination(1, TimeUnit.MILLISECONDS);
   }
+
+  @Test
+  public void startFailsOnNonexistentNamespace() {
+    WorkflowServiceStubs serviceLocal =
+        WorkflowServiceStubs.newServiceStubs(
+            WorkflowServiceStubsOptions.newBuilder().setTarget(serviceAddress).build());
+    WorkflowClient clientLocal =
+        WorkflowClient.newInstance(
+            serviceLocal, WorkflowClientOptions.newBuilder().setNamespace("i_dont_exist").build());
+    WorkerFactory factoryLocal = WorkerFactory.newInstance(clientLocal);
+    factoryLocal.newWorker("task-queue");
+
+    StatusRuntimeException ex = assertThrows(StatusRuntimeException.class, factoryLocal::start);
+    assertEquals(Status.Code.NOT_FOUND, ex.getStatus().getCode());
+
+    factoryLocal.shutdownNow();
+    factoryLocal.awaitTermination(5, TimeUnit.SECONDS);
+    serviceLocal.shutdownNow();
+    serviceLocal.awaitTermination(5, TimeUnit.SECONDS);
+  }
 }