connecting to Bigtable emulator using environment variable

google-cloud-clients/google-cloud-bigtable/src/main/java/com/google/cloud/bigtable/admin/v2/BigtableInstanceAdminSettings.java

@@ -15,6 +15,8 @@
  */
 package com.google.cloud.bigtable.admin.v2;
 
+import static com.google.cloud.bigtable.admin.v2.BigtableTableAdminSettings.BIGTABLE_EMULATOR_HOST_ENV_VAR;
+
 import com.google.api.gax.core.CredentialsProvider;
 import com.google.cloud.bigtable.admin.v2.stub.BigtableInstanceAdminStubSettings;
 import com.google.common.base.Preconditions;
@@ -79,6 +81,9 @@ public Builder toBuilder() {
 
   /** Returns a new builder for this class. */
   public static Builder newBuilder() {
+    Preconditions.checkState(
+        System.getenv(BIGTABLE_EMULATOR_HOST_ENV_VAR) == null,
+        "BigtableInstanceAdminSettings doesn't supported on Emulator");
     return new Builder();
   }
 

google-cloud-clients/google-cloud-bigtable/src/main/java/com/google/cloud/bigtable/admin/v2/BigtableTableAdminSettings.java

@@ -21,9 +21,11 @@
 import com.google.api.gax.grpc.InstantiatingGrpcChannelProvider;
 import com.google.cloud.bigtable.admin.v2.stub.BigtableTableAdminStubSettings;
 import com.google.common.base.Preconditions;
+import com.google.common.base.Strings;
 import com.google.common.base.Verify;
 import io.grpc.ManagedChannelBuilder;
 import java.io.IOException;
+import java.util.logging.Logger;
 import javax.annotation.Nullable;
 
 /**
@@ -48,6 +50,10 @@
  * }</pre>
  */
 public final class BigtableTableAdminSettings {
+
+  private static final Logger LOGGER = Logger.getLogger(BigtableTableAdminSettings.class.getName());
+  static final String BIGTABLE_EMULATOR_HOST_ENV_VAR = "BIGTABLE_EMULATOR_HOST";
+
   private final String projectId;
   private final String instanceId;
   private final BigtableTableAdminStubSettings stubSettings;
@@ -84,19 +90,46 @@ public Builder toBuilder() {
     return new Builder(this);
   }
 
-  /** Returns a new builder for this class. */
+  /**
+   * Returns a new builder for this class.
+   *
+   * <p>If emulator configuration provided in BIGTABLE_EMULATOR_HOST environment variable then it
+   * creates a builder preconfigured to connect to Bigtable using emulator hostname and port number.
+   */
   public static Builder newBuilder() {
+    String hostAndPort = System.getenv(BIGTABLE_EMULATOR_HOST_ENV_VAR);
+    if (!Strings.isNullOrEmpty(hostAndPort)) {
+      int port;
+      try {
+        port = Integer.parseInt(hostAndPort.substring(hostAndPort.lastIndexOf(":") + 1));
+        return newBuilderForEmulator(hostAndPort.substring(0, hostAndPort.lastIndexOf(":")), port);
+      } catch (NumberFormatException | IndexOutOfBoundsException ex) {
+        throw new RuntimeException(
+            "Invalid host/port in "
+                + BIGTABLE_EMULATOR_HOST_ENV_VAR
+                + " environment variable: "
+                + hostAndPort);
+      }
+    }
     return new Builder();
   }
 
-  /** Create a new builder preconfigured to connect to the Bigtable emulator. */
+  /** Create a new builder preconfigured to connect to the Bigtable emulator with port number. */
   public static Builder newBuilderForEmulator(int port) {
-    Builder builder = newBuilder().setProjectId("fake-project").setInstanceId("fake-instance");
+    return newBuilderForEmulator("localhost", port);
+  }
+
+  /**
+   * Creates a new builder preconfigured to connect to the Bigtable emulator with host name and port
+   * number.
+   */
+  public static Builder newBuilderForEmulator(String hostname, int port) {
+    Builder builder = new Builder();
 
     builder
         .stubSettings()
         .setCredentialsProvider(NoCredentialsProvider.create())
-        .setEndpoint("localhost:" + port)
+        .setEndpoint(hostname + ":" + port)
         .setTransportChannelProvider(
             InstantiatingGrpcChannelProvider.newBuilder()
                 .setPoolSize(1)
@@ -109,6 +142,7 @@ public ManagedChannelBuilder apply(ManagedChannelBuilder input) {
                     })
                 .build());
 
+    LOGGER.info("Connecting to the Bigtable emulator at " + hostname + ":" + port);
     return builder;
   }
 

google-cloud-clients/google-cloud-bigtable/src/main/java/com/google/cloud/bigtable/data/v2/BigtableDataSettings.java

@@ -23,7 +23,9 @@
 import com.google.cloud.bigtable.data.v2.models.Query;
 import com.google.cloud.bigtable.data.v2.models.Row;
 import com.google.cloud.bigtable.data.v2.stub.EnhancedBigtableStubSettings;
+import com.google.common.base.Strings;
 import io.grpc.ManagedChannelBuilder;
+import java.util.logging.Logger;
 import javax.annotation.Nonnull;
 
 /**
@@ -55,27 +57,56 @@
  * EnhancedBigtableStubSettings}, which is exposed as {@link Builder#stubSettings()}.
  */
 public final class BigtableDataSettings {
+
+  private static final Logger LOGGER = Logger.getLogger(BigtableDataSettings.class.getName());
+  private static final String BIGTABLE_EMULATOR_HOST_ENV_VAR = "BIGTABLE_EMULATOR_HOST";
+
   private final EnhancedBigtableStubSettings stubSettings;
 
   private BigtableDataSettings(Builder builder) {
     stubSettings = builder.stubSettings().build();
   }
 
-  /** Create a new builder. */
+  /**
+   * Create a new builder.
+   *
+   * <p>If emulator configuration provided in BIGTABLE_EMULATOR_HOST environment variable then it
+   * creates a builder preconfigured to connect to Bigtable using emulator hostname and port number.
+   */
   public static Builder newBuilder() {
+    String hostAndPort = System.getenv(BIGTABLE_EMULATOR_HOST_ENV_VAR);
+    if (!Strings.isNullOrEmpty(hostAndPort)) {
+      try {
+        int lastIndexOfCol = hostAndPort.lastIndexOf(":");
+        int port = Integer.parseInt(hostAndPort.substring(lastIndexOfCol + 1));
+        return newBuilderForEmulator(hostAndPort.substring(0, lastIndexOfCol), port);
+      } catch (NumberFormatException | IndexOutOfBoundsException ex) {
+        throw new RuntimeException(
+            "Invalid host/port in "
+                + BIGTABLE_EMULATOR_HOST_ENV_VAR
+                + " environment variable: "
+                + hostAndPort);
+      }
+    }
     return new Builder();
   }
 
-  /** Create a new builder preconfigured to connect to the Bigtable emulator. */
+  /** Create a new builder preconfigured to connect to the Bigtable emulator with port number. */
   public static Builder newBuilderForEmulator(int port) {
-    Builder builder = newBuilder();
+    return newBuilderForEmulator("localhost", port);
+  }
+
+  /**
+   * Creates a new builder preconfigured to connect to the Bigtable emulator with a host name and
+   * port number.
+   */
+  public static Builder newBuilderForEmulator(String hostname, int port) {
+    Builder builder = new Builder();
 
     builder
         .stubSettings()
-        .setProjectId("fake-project")
-        .setInstanceId("fake-instance")
         .setCredentialsProvider(NoCredentialsProvider.create())
-        .setEndpoint("localhost:" + port)
+        .setEndpoint(hostname + ":" + port)
         .setTransportChannelProvider(
             InstantiatingGrpcChannelProvider.newBuilder()
                 .setMaxInboundMessageSize(256 * 1024 * 1024)
@@ -89,6 +120,7 @@ public ManagedChannelBuilder apply(ManagedChannelBuilder input) {
                     })
                 .build());
 
+    LOGGER.info("Connecting to the Bigtable emulator at " + hostname + ":" + port);
     return builder;
   }
 

google-cloud-clients/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/data/v2/it/env/EmulatorEnv.java

@@ -39,10 +39,16 @@ public void start() throws Exception {
 
     tableAdminClient =
         BigtableTableAdminClient.create(
-            BigtableTableAdminSettings.newBuilderForEmulator(emulator.getPort()).build());
+            BigtableTableAdminSettings.newBuilderForEmulator(emulator.getPort())
+                .setProjectId("fake-project")
+                .setInstanceId("fake-instance")
+                .build());
     dataClient =
         BigtableDataClient.create(
-            BigtableDataSettings.newBuilderForEmulator(emulator.getPort()).build());
+            BigtableDataSettings.newBuilderForEmulator(emulator.getPort())
+                .setProjectId("fake-project")
+                .setInstanceId("fake-instance")
+                .build());
 
     tableAdminClient.createTable(CreateTableRequest.of(TABLE_ID).addFamily(FAMILY_ID));
   }

google-cloud-clients/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/data/v2/it/env/TestEnvRule.java

@@ -15,6 +15,8 @@
  */
 package com.google.cloud.bigtable.data.v2.it.env;
 
+import static com.google.common.truth.TruthJUnit.assume;
+
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import org.junit.rules.ExternalResource;
@@ -37,14 +39,21 @@
  * <p>By default, {@code emulator} will be used
  */
 public class TestEnvRule extends ExternalResource {
-  private static final Logger LOGGER = Logger.getLogger(TestEnvRule.class.getName());
 
+  private static final Logger LOGGER = Logger.getLogger(TestEnvRule.class.getName());
+  private static final String BIGTABLE_EMULATOR_HOST_ENV_VAR = "BIGTABLE_EMULATOR_HOST";
   private static final String ENV_PROPERTY = "bigtable.env";
 
   private TestEnv testEnv;
 
   @Override
   protected void before() throws Throwable {
+    assume()
+        .withMessage(
+            "Integration tests can't run with the BIGTABLE_EMULATOR_HOST environment variable set"
+                + ". Please use the emulator-it maven profile instead")
+        .that(System.getenv())
+        .doesNotContainKey(BIGTABLE_EMULATOR_HOST_ENV_VAR);
     String env = System.getProperty(ENV_PROPERTY, "emulator");
 
     switch (env) {