feat: add some docs, use only setCredentials in DatastoreOptions (#1467)

* feat: add some docs, use only setCredentials in DatastoreOptions

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

---------

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: kolea2

README.md

@@ -50,7 +50,7 @@ If you are using Maven without the BOM, add this to your dependencies:
 If you are using Gradle 5.x or later, add this to your dependencies:
 
 ```Groovy
-implementation platform('com.google.cloud:libraries-bom:26.39.0')
+implementation platform('com.google.cloud:libraries-bom:26.40.0')
 
 implementation 'com.google.cloud:google-cloud-datastore'
 ```

google-cloud-datastore/src/main/java/com/google/cloud/datastore/DatastoreOptions.java

@@ -19,7 +19,6 @@
 import static com.google.cloud.datastore.Validator.validateNamespace;
 
 import com.google.api.core.BetaApi;
-import com.google.api.gax.core.CredentialsProvider;
 import com.google.api.gax.grpc.InstantiatingGrpcChannelProvider;
 import com.google.api.gax.rpc.TransportChannelProvider;
 import com.google.cloud.ServiceDefaults;
@@ -51,7 +50,6 @@ public class DatastoreOptions extends ServiceOptions<Datastore, DatastoreOptions
   public static final String LOCAL_HOST_ENV_VAR = "DATASTORE_EMULATOR_HOST";
 
   private transient TransportChannelProvider channelProvider = null;
-  private transient CredentialsProvider credentialsProvider = null;
 
   private final String namespace;
   private final String databaseId;
@@ -89,7 +87,6 @@ public static class Builder extends ServiceOptions.Builder<Datastore, DatastoreO
     private String namespace;
     private String databaseId;
     private TransportChannelProvider channelProvider = null;
-    private CredentialsProvider credentialsProvider = null;
     private String host;
     private TransportOptions transportOptions;
 
@@ -100,7 +97,6 @@ private Builder(DatastoreOptions options) {
       this.namespace = options.namespace;
       this.databaseId = options.databaseId;
       this.channelProvider = validateChannelProvider(options.channelProvider);
-      this.credentialsProvider = options.credentialsProvider;
     }
 
     @Override
@@ -113,6 +109,9 @@ public Builder setTransportOptions(TransportOptions transportOptions) {
       return super.setTransportOptions(transportOptions);
     }
 
+    /**
+     * Sets the transport to gRPC. Note this functionality is experimental and subject to change.
+     */
     @BetaApi
     public Builder setTransportOptions(GrpcTransportOptions transportOptions) {
       this.transportOptions = transportOptions;
@@ -128,6 +127,11 @@ public Builder setHost(String host) {
     /**
      * Sets the {@link TransportChannelProvider} to use with this Datastore client.
      *
+     * <p>This is only compatible with clients using a gRPC transport (see {@code
+     * DatastoreOptions#setTransportOptions(GrpcTransportOptions)} for more details).
+     *
+     * <p>This functionality is experimental and subject to change.
+     *
      * @param channelProvider A InstantiatingGrpcChannelProvider object that defines the transport
      *     provider for this client.
      */
@@ -137,18 +141,6 @@ public Builder setChannelProvider(TransportChannelProvider channelProvider) {
       return this;
     }
 
-    /**
-     * Sets the {@link CredentialsProvider} to use with this Datastore client.
-     *
-     * @param credentialsProvider A CredentialsProvider object that defines the credential provider
-     *     for this client.
-     */
-    @BetaApi
-    public Builder setCredentialsProvider(CredentialsProvider credentialsProvider) {
-      this.credentialsProvider = credentialsProvider;
-      return this;
-    }
-
     @Override
     public DatastoreOptions build() {
       if (this.host == null && this.transportOptions instanceof GrpcTransportOptions) {
@@ -183,8 +175,7 @@ private DatastoreOptions(Builder builder) {
     namespace = MoreObjects.firstNonNull(builder.namespace, defaultNamespace());
     databaseId = MoreObjects.firstNonNull(builder.databaseId, DEFAULT_DATABASE_ID);
 
-    if (getTransportOptions() instanceof HttpTransportOptions
-        && (builder.channelProvider != null || builder.credentialsProvider != null)) {
+    if (getTransportOptions() instanceof HttpTransportOptions && builder.channelProvider != null) {
       throw new IllegalArgumentException(
           "Only gRPC transport allows setting of channel provider or credentials provider");
     } else if (getTransportOptions() instanceof GrpcTransportOptions) {
@@ -193,18 +184,9 @@ private DatastoreOptions(Builder builder) {
               ? builder.channelProvider
               : GrpcTransportOptions.setUpChannelProvider(
                   DatastoreSettings.defaultGrpcTransportProviderBuilder(), this);
-
-      this.credentialsProvider =
-          builder.credentialsProvider != null
-              ? builder.credentialsProvider
-              : GrpcTransportOptions.setUpCredentialsProvider(this);
     }
   }
 
-  public CredentialsProvider getCredentialsProvider() {
-    return credentialsProvider;
-  }
-
   public TransportChannelProvider getTransportChannelProvider() {
     return channelProvider;
   }

google-cloud-datastore/src/main/java/com/google/cloud/datastore/spi/v1/GrpcDatastoreRpc.java

@@ -36,6 +36,7 @@
 import com.google.cloud.datastore.v1.DatastoreSettings;
 import com.google.cloud.datastore.v1.stub.DatastoreStubSettings;
 import com.google.cloud.datastore.v1.stub.GrpcDatastoreStub;
+import com.google.cloud.grpc.GrpcTransportOptions;
 import com.google.common.base.Strings;
 import com.google.datastore.v1.AllocateIdsRequest;
 import com.google.datastore.v1.AllocateIdsResponse;
@@ -169,7 +170,8 @@ private ClientContext getClientContext(DatastoreOptions datastoreOptions) throws
 
     DatastoreSettingsBuilder settingsBuilder =
         new DatastoreSettingsBuilder(DatastoreSettings.newBuilder().build());
-    settingsBuilder.setCredentialsProvider(datastoreOptions.getCredentialsProvider());
+    settingsBuilder.setCredentialsProvider(
+        GrpcTransportOptions.setUpCredentialsProvider(datastoreOptions));
     settingsBuilder.setTransportChannelProvider(datastoreOptions.getTransportChannelProvider());
     settingsBuilder.setInternalHeaderProvider(internalHeaderProvider);
     settingsBuilder.setHeaderProvider(

google-cloud-datastore/src/test/java/com/google/cloud/datastore/DatastoreOptionsTest.java

@@ -22,7 +22,6 @@
 import static org.junit.Assert.assertSame;
 import static org.junit.Assert.assertTrue;
 
-import com.google.api.gax.core.NoCredentialsProvider;
 import com.google.api.gax.grpc.ChannelPoolSettings;
 import com.google.api.gax.grpc.InstantiatingGrpcChannelProvider;
 import com.google.cloud.NoCredentials;
@@ -92,7 +91,6 @@ public void testDatastore() {
 
   @Test
   public void testCustomChannelAndCredentials() {
-    NoCredentialsProvider noCredentialsProvider = NoCredentialsProvider.create();
     InstantiatingGrpcChannelProvider channelProvider =
         DatastoreSettings.defaultGrpcTransportProviderBuilder()
             .setChannelPoolSettings(
@@ -108,11 +106,10 @@ public void testCustomChannelAndCredentials() {
             .setDatabaseId(DATABASE_ID)
             .setTransportOptions(GrpcTransportOptions.newBuilder().build())
             .setChannelProvider(channelProvider)
-            .setCredentialsProvider(noCredentialsProvider)
+            .setCredentials(NoCredentials.getInstance())
             .setHost("http://localhost:" + PORT)
             .build();
     assertEquals(datastoreOptions.getTransportChannelProvider(), channelProvider);
-    assertEquals(datastoreOptions.getCredentialsProvider(), noCredentialsProvider);
   }
 
   @Test
@@ -131,7 +128,7 @@ public void testInvalidConfigForHttp() {
                             .setMaxChannelCount(20)
                             .build())
                     .build())
-            .setCredentialsProvider(NoCredentialsProvider.create())
+            .setCredentials(NoCredentials.getInstance())
             .setHost("http://localhost:" + PORT);
     Assert.assertThrows(IllegalArgumentException.class, options::build);
   }
@@ -146,11 +143,9 @@ public void testTransport() {
         DatastoreOptions.newBuilder()
             .setTransportOptions(GrpcTransportOptions.newBuilder().build())
             .setProjectId(PROJECT_ID)
-            .setCredentialsProvider(NoCredentialsProvider.create())
+            .setCredentials(NoCredentials.getInstance())
             .build();
     assertThat(grpcTransportOptions.getTransportOptions()).isInstanceOf(GrpcTransportOptions.class);
-    assertThat(grpcTransportOptions.getCredentialsProvider())
-        .isInstanceOf(NoCredentialsProvider.class);
     assertThat(grpcTransportOptions.getTransportChannelProvider())
         .isInstanceOf(InstantiatingGrpcChannelProvider.class);
   }
@@ -161,7 +156,7 @@ public void testHostWithGrpcAndHttp() {
         DatastoreOptions.newBuilder()
             .setTransportOptions(GrpcTransportOptions.newBuilder().build())
             .setProjectId(PROJECT_ID)
-            .setCredentialsProvider(NoCredentialsProvider.create())
+            .setCredentials(NoCredentials.getInstance())
             .build();
     assertThat(grpcTransportOptions.getHost()).isEqualTo(DatastoreSettings.getDefaultEndpoint());
     assertThat(grpcTransportOptions.getHost()).isEqualTo("datastore.googleapis.com:443");
@@ -172,7 +167,7 @@ public void testHostWithGrpcAndHttp() {
             .setTransportOptions(GrpcTransportOptions.newBuilder().build())
             .setHost(customHost)
             .setProjectId(PROJECT_ID)
-            .setCredentialsProvider(NoCredentialsProvider.create())
+            .setCredentials(NoCredentials.getInstance())
             .build();
     assertThat(grpcTransportOptionsCustomHost.getHost()).isEqualTo(customHost);