fix: add nio entry to user-agent (#774)

Introduce StorageOptionsUtil which provides utilities and default instance access for StorageOptions which include our new user-agent entry.

To all tests which called com.google.cloud.storage.contrib.nio.CloudStorageFileSystemProvider.setStorageOptions in their @before, there is now a corresponding @after which sets the storageOptions back to defaults

google-cloud-nio/src/main/java/com/google/cloud/storage/contrib/nio/CloudStorageFileSystemProvider.java

@@ -93,7 +93,7 @@ public final class CloudStorageFileSystemProvider extends FileSystemProvider {
   private final @Nullable String userProject;
 
   // used only when we create a new instance of CloudStorageFileSystemProvider.
-  private static StorageOptions futureStorageOptions;
+  private static StorageOptions futureStorageOptions = StorageOptionsUtil.getDefaultInstance();
 
   private static class LazyPathIterator extends AbstractIterator<Path> {
     private final Iterator<Blob> blobIterator;
@@ -198,20 +198,18 @@ public CloudStorageFileSystemProvider() {
    */
   CloudStorageFileSystemProvider(
       @Nullable String userProject, @Nullable StorageOptions gcsStorageOptions) {
-    this.storageOptions = gcsStorageOptions;
+    this.storageOptions =
+        gcsStorageOptions != null
+            ? StorageOptionsUtil.mergeOptionsWithUserAgent(gcsStorageOptions)
+            : StorageOptionsUtil.getDefaultInstance();
     this.userProject = userProject;
   }
 
   // Initialize this.storage, once. This may throw an exception if default authentication
   // credentials are not available (hence not doing it in the ctor).
   private void initStorage() {
-    if (this.storage != null) {
-      return;
-    }
-    if (storageOptions == null) {
-      this.storage = StorageOptions.getDefaultInstance().getService();
-    } else {
-      this.storage = storageOptions.getService();
+    if (this.storage == null) {
+      doInitStorage();
     }
   }
 
@@ -1037,4 +1035,9 @@ private IOException asIoException(StorageException oops) {
     }
     return new IOException(oops.getMessage(), oops);
   }
+
+  @VisibleForTesting
+  void doInitStorage() {
+    this.storage = storageOptions.getService();
+  }
 }

google-cloud-nio/src/main/java/com/google/cloud/storage/contrib/nio/StorageOptionsUtil.java

@@ -0,0 +1,119 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License 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 com.google.cloud.storage.contrib.nio;
+
+import com.google.api.gax.rpc.FixedHeaderProvider;
+import com.google.api.gax.rpc.HeaderProvider;
+import com.google.cloud.storage.StorageOptions;
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.collect.ImmutableMap;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Properties;
+
+final class StorageOptionsUtil {
+  static final String USER_AGENT_ENTRY_NAME = "gcloud-java-nio";
+  static final String USER_AGENT_ENTRY_VERSION = getVersion();
+  private static final String USER_AGENT_ENTRY =
+      String.format("%s/%s", USER_AGENT_ENTRY_NAME, USER_AGENT_ENTRY_VERSION);
+  private static final FixedHeaderProvider DEFAULT_HEADER_PROVIDER =
+      FixedHeaderProvider.create("user-agent", USER_AGENT_ENTRY);
+
+  private static final StorageOptions DEFAULT_STORAGE_OPTIONS_INSTANCE =
+      StorageOptions.newBuilder().setHeaderProvider(DEFAULT_HEADER_PROVIDER).build();
+  private static final FixedHeaderProvider EMTPY_HEADER_PROVIDER =
+      FixedHeaderProvider.create(Collections.emptyMap());
+
+  private StorageOptionsUtil() {}
+
+  static StorageOptions getDefaultInstance() {
+    return DEFAULT_STORAGE_OPTIONS_INSTANCE;
+  }
+
+  static StorageOptions mergeOptionsWithUserAgent(StorageOptions providedStorageOptions) {
+    if (providedStorageOptions == DEFAULT_STORAGE_OPTIONS_INSTANCE) {
+      return providedStorageOptions;
+    }
+
+    String userAgent = providedStorageOptions.getUserAgent();
+    if (userAgent == null) {
+      return nullSafeSet(providedStorageOptions, DEFAULT_HEADER_PROVIDER);
+    } else {
+      if (!userAgent.contains(USER_AGENT_ENTRY_NAME)) {
+        HeaderProvider providedHeaderProvider = getHeaderProvider(providedStorageOptions);
+        Map<String, String> newHeaders = new HashMap<>(providedHeaderProvider.getHeaders());
+        newHeaders.put("user-agent", String.format("%s %s", userAgent, USER_AGENT_ENTRY));
+        FixedHeaderProvider headerProvider =
+            FixedHeaderProvider.create(ImmutableMap.copyOf(newHeaders));
+        return nullSafeSet(providedStorageOptions, headerProvider);
+      } else {
+        return providedStorageOptions;
+      }
+    }
+  }
+
+  /**
+   * Due to some complex interactions between init and mocking, it's possible that the builder
+   * instance returned from {@link StorageOptions#toBuilder()} can be null. This utility method will
+   * attempt to create the builder and set the new header provider. If however the builder instance
+   * is null, the orignal options will be returned without setting the header provider.
+   *
+   * <p>Since this method is only every called by us trying to add our user-agent entry to the
+   * headers this makes our attempt effectively a no-op, which is much better than failing customer
+   * code.
+   */
+  private static StorageOptions nullSafeSet(
+      StorageOptions storageOptions, HeaderProvider headerProvider) {
+    StorageOptions.Builder builder = storageOptions.toBuilder();
+    if (builder == null) {
+      return storageOptions;
+    } else {
+      return builder.setHeaderProvider(headerProvider).build();
+    }
+  }
+
+  /** Resolve the version of google-cloud-nio for inclusion in request meta-data */
+  private static String getVersion() {
+    // attempt to read the library's version from a properties file generated during the build
+    // this value should be read and cached for later use
+    String version = "";
+    try (InputStream inputStream =
+        CloudStorageFileSystemProvider.class.getResourceAsStream(
+            "/META-INF/maven/com.google.cloud/google-cloud-nio/pom.properties")) {
+      if (inputStream != null) {
+        final Properties properties = new Properties();
+        properties.load(inputStream);
+        version = properties.getProperty("version");
+      }
+    } catch (IOException e) {
+      // ignore
+    }
+    return version;
+  }
+
+  /**
+   * {@link com.google.cloud.ServiceOptions} does not specify a getter for the headerProvider, so
+   * instead merge with an empty provider.
+   */
+  @VisibleForTesting
+  static HeaderProvider getHeaderProvider(StorageOptions options) {
+    return options.getMergedHeaderProvider(EMTPY_HEADER_PROVIDER);
+  }
+}

google-cloud-nio/src/test/java/com/google/cloud/storage/contrib/nio/CloudStorageFileAttributeViewTest.java

@@ -30,6 +30,7 @@
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.nio.file.attribute.FileTime;
+import org.junit.After;
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Rule;
@@ -52,6 +53,11 @@ public void before() {
     path = Paths.get(URI.create("gs://red/water"));
   }
 
+  @After
+  public void after() {
+    CloudStorageFileSystemProvider.setStorageOptions(StorageOptionsUtil.getDefaultInstance());
+  }
+
   @Test
   public void testReadAttributes() throws IOException {
     Files.write(path, HAPPY, CloudStorageOptions.withCacheControl("potato"));

google-cloud-nio/src/test/java/com/google/cloud/storage/contrib/nio/CloudStorageFileAttributesTest.java

@@ -29,6 +29,7 @@
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import org.junit.After;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
@@ -53,6 +54,11 @@ public void before() {
     dir = Paths.get(URI.create("gs://bucket/randompath/"));
   }
 
+  @After
+  public void after() {
+    CloudStorageFileSystemProvider.setStorageOptions(StorageOptionsUtil.getDefaultInstance());
+  }
+
   @Test
   public void testCacheControl() throws IOException {
     Files.write(path, HAPPY, CloudStorageOptions.withCacheControl("potato"));

google-cloud-nio/src/test/java/com/google/cloud/storage/contrib/nio/CloudStorageFileSystemProviderTest.java

@@ -26,6 +26,7 @@
 import static java.nio.file.StandardOpenOption.CREATE_NEW;
 import static java.nio.file.StandardOpenOption.TRUNCATE_EXISTING;
 import static java.nio.file.StandardOpenOption.WRITE;
+import static org.junit.Assert.assertTrue;
 
 import com.google.cloud.storage.contrib.nio.testing.LocalStorageHelper;
 import com.google.cloud.testing.junit4.MultipleAttemptsRule;
@@ -52,6 +53,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import org.junit.After;
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Rule;
@@ -99,6 +101,11 @@ public void before() {
     CloudStorageFileSystemProvider.setStorageOptions(LocalStorageHelper.getOptions());
   }
 
+  @After
+  public void after() {
+    CloudStorageFileSystemProvider.setStorageOptions(StorageOptionsUtil.getDefaultInstance());
+  }
+
   @Test
   public void testSize() throws Exception {
     Path path = Paths.get(URI.create("gs://bucket/wat"));
@@ -795,6 +802,21 @@ public void testFromSpace() throws Exception {
     assertThat(path4.toString()).isEqualTo("/with/a%20percent");
   }
 
+  @Test
+  public void testVersion_matchesAcceptablePatterns() {
+    String acceptableVersionPattern = "|(?:\\d+\\.\\d+\\.\\d+(?:-.*?)?(?:-SNAPSHOT)?)";
+    String version = StorageOptionsUtil.USER_AGENT_ENTRY_VERSION;
+    assertTrue(
+        String.format("the loaded version '%s' did not match the acceptable pattern", version),
+        version.matches(acceptableVersionPattern));
+  }
+
+  @Test
+  public void getUserAgentStartsWithCorrectToken() {
+    assertThat(String.format("gcloud-java-nio/%s", StorageOptionsUtil.USER_AGENT_ENTRY_VERSION))
+        .startsWith("gcloud-java-nio/");
+  }
+
   private static CloudStorageConfiguration permitEmptyPathComponents(boolean value) {
     return CloudStorageConfiguration.builder().permitEmptyPathComponents(value).build();
   }

google-cloud-nio/src/test/java/com/google/cloud/storage/contrib/nio/CloudStorageFileSystemTest.java

@@ -46,6 +46,7 @@
 import java.nio.file.attribute.BasicFileAttributes;
 import java.util.ArrayList;
 import java.util.List;
+import org.junit.After;
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Rule;
@@ -73,6 +74,11 @@ public void before() {
     CloudStorageFileSystemProvider.setStorageOptions(LocalStorageHelper.getOptions());
   }
 
+  @After
+  public void after() {
+    CloudStorageFileSystemProvider.setStorageOptions(StorageOptionsUtil.getDefaultInstance());
+  }
+
   @Test
   public void checkDefaultOptions() throws IOException {
     // 1. We get the normal default if we don't do anything special.

google-cloud-nio/src/test/java/com/google/cloud/storage/contrib/nio/CloudStorageIsDirectoryTest.java

@@ -29,6 +29,7 @@
 import com.google.cloud.testing.junit4.MultipleAttemptsRule;
 import com.google.common.collect.Lists;
 import java.nio.file.Files;
+import org.junit.After;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
@@ -57,6 +58,11 @@ public void before() {
     CloudStorageFileSystemProvider.setStorageOptions(mockOptions);
   }
 
+  @After
+  public void after() {
+    CloudStorageFileSystemProvider.setStorageOptions(StorageOptionsUtil.getDefaultInstance());
+  }
+
   @Test
   public void testIsDirectoryNoUserProject() {
     CloudStorageFileSystem fs =

google-cloud-nio/src/test/java/com/google/cloud/storage/contrib/nio/CloudStorageLateInitializationTest.java

@@ -16,56 +16,41 @@
 
 package com.google.cloud.storage.contrib.nio;
 
-import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
 
-import com.google.cloud.storage.Storage;
-import com.google.cloud.storage.StorageOptions;
 import com.google.cloud.testing.junit4.MultipleAttemptsRule;
 import java.net.URI;
-import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
+import org.mockito.Spy;
+import org.mockito.junit.MockitoJUnitRunner;
 
 /** Unit tests for {@link CloudStorageFileSystemProvider} late initialization. */
-@RunWith(JUnit4.class)
+@RunWith(MockitoJUnitRunner.class)
 public class CloudStorageLateInitializationTest {
   @Rule public final MultipleAttemptsRule multipleAttemptsRule = new MultipleAttemptsRule(3);
 
-  private StorageOptions mockOptions;
-
-  @Before
-  public void before() {
-    mockOptions = mock(StorageOptions.class);
-    Storage mockStorage = mock(Storage.class);
-    when(mockOptions.getService()).thenReturn(mockStorage);
-    CloudStorageFileSystemProvider.setStorageOptions(mockOptions);
-  }
+  @Spy private final CloudStorageFileSystemProvider provider = new CloudStorageFileSystemProvider();
 
   @Test
   public void ctorDoesNotCreateStorage() {
-    new CloudStorageFileSystemProvider();
-    verify(mockOptions, never()).getService();
+    verify(provider, never()).doInitStorage();
   }
 
   @Test
   public void getPathCreatesStorageOnce() {
-    CloudStorageFileSystemProvider provider = new CloudStorageFileSystemProvider();
     provider.getPath(URI.create("gs://bucket1/wat"));
     provider.getPath(URI.create("gs://bucket2/wat"));
-    verify(mockOptions, times(1)).getService();
+    verify(provider, times(1)).doInitStorage();
   }
 
   @Test
   public void getFileSystemCreatesStorageOnce() {
-    CloudStorageFileSystemProvider provider = new CloudStorageFileSystemProvider();
     provider.getFileSystem(URI.create("gs://bucket1"));
     provider.getFileSystem(URI.create("gs://bucket2"));
-    verify(mockOptions, times(1)).getService();
+    verify(provider, times(1)).doInitStorage();
   }
 }

google-cloud-nio/src/test/java/com/google/cloud/storage/contrib/nio/CloudStorageOptionsTest.java

@@ -28,6 +28,7 @@
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import org.junit.After;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
@@ -44,6 +45,11 @@ public void before() {
     CloudStorageFileSystemProvider.setStorageOptions(LocalStorageHelper.getOptions());
   }
 
+  @After
+  public void after() {
+    CloudStorageFileSystemProvider.setStorageOptions(StorageOptionsUtil.getDefaultInstance());
+  }
+
   @Test
   public void testWithoutCaching() throws IOException {
     Path path = Paths.get(URI.create("gs://bucket/path"));

google-cloud-nio/src/test/java/com/google/cloud/storage/contrib/nio/CloudStoragePathTest.java

@@ -30,6 +30,7 @@
 import java.nio.file.FileSystems;
 import java.nio.file.Path;
 import java.nio.file.ProviderMismatchException;
+import org.junit.After;
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Rule;
@@ -47,6 +48,11 @@ public void before() {
     CloudStorageFileSystemProvider.setStorageOptions(LocalStorageHelper.getOptions());
   }
 
+  @After
+  public void after() {
+    CloudStorageFileSystemProvider.setStorageOptions(StorageOptionsUtil.getDefaultInstance());
+  }
+
   @Test
   public void testCreate_neverRemoveExtraSlashes() throws IOException {
     try (CloudStorageFileSystem fs = CloudStorageFileSystem.forBucket("doodle")) {