HADOOP-18684. S3A filesystem to support binding to to other URI schemes (#5521)

Contributed by Harshit Gupta

hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/S3A.java

@@ -18,14 +18,16 @@
 
 package org.apache.hadoop.fs.s3a;
 
+import java.io.IOException;
+import java.net.URI;
+import java.net.URISyntaxException;
+
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.DelegateToFileSystem;
 
-import java.io.IOException;
-import java.net.URI;
-import java.net.URISyntaxException;
+import static org.apache.hadoop.fs.s3a.Constants.FS_S3A;
 
 /**
  * S3A implementation of AbstractFileSystem.
@@ -37,7 +39,8 @@ public class S3A extends DelegateToFileSystem {
 
   public S3A(URI theUri, Configuration conf)
       throws IOException, URISyntaxException {
-    super(theUri, new S3AFileSystem(), conf, "s3a", false);
+    super(theUri, new S3AFileSystem(), conf,
+        theUri.getScheme().isEmpty() ? FS_S3A : theUri.getScheme(), false);
   }
 
   @Override

hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/S3AFileSystem.java

@@ -404,6 +404,11 @@ public class S3AFileSystem extends FileSystem implements StreamCapabilities,
    */
   private final Set<Path> deleteOnExit = new TreeSet<>();
 
+  /**
+   * Scheme for the current filesystem.
+   */
+  private String scheme = FS_S3A;
+
   /** Add any deprecated keys. */
   @SuppressWarnings("deprecation")
   private static void addDeprecatedKeys() {
@@ -617,6 +622,7 @@ public class S3AFileSystem extends FileSystem implements StreamCapabilities,
       vectoredActiveRangeReads = intOption(conf,
               AWS_S3_VECTOR_ACTIVE_RANGE_READS, DEFAULT_AWS_S3_VECTOR_ACTIVE_RANGE_READS, 1);
       vectoredIOContext = populateVectoredIOContext(conf);
+      scheme = (this.uri != null && this.uri.getScheme() != null) ? this.uri.getScheme() : FS_S3A;
     } catch (AmazonClientException e) {
       // amazon client exception: stop all services then throw the translation
       cleanupWithLogger(LOG, span);
@@ -1162,7 +1168,7 @@ public class S3AFileSystem extends FileSystem implements StreamCapabilities,
    */
   @Override
   public String getScheme() {
-    return "s3a";
+    return this.scheme;
   }
 
   /**

hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/ITestS3AUrlScheme.java

@@ -0,0 +1,51 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.hadoop.fs.s3a;
+
+import java.io.IOException;
+import java.net.URI;
+import java.net.URISyntaxException;
+
+import org.junit.Test;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+
+public class ITestS3AUrlScheme extends AbstractS3ATestBase{
+  @Override
+  protected Configuration createConfiguration() {
+    Configuration conf = super.createConfiguration();
+    conf.set("fs.s3.impl", "org.apache.hadoop.fs.s3a.S3AFileSystem");
+    return conf;
+  }
+
+  @Test
+  public void testFSScheme() throws IOException, URISyntaxException {
+    FileSystem fs = FileSystem.get(new URI("s3://mybucket/path"),
+        getConfiguration());
+    try {
+      assertEquals("s3", fs.getScheme());
+      Path path = fs.makeQualified(new Path("tmp/path"));
+      assertEquals("s3", path.toUri().getScheme());
+    } finally {
+      fs.close();
+    }
+  }
+}

hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/fileContext/ITestS3AFileContext.java

@@ -13,11 +13,34 @@
  */
 package org.apache.hadoop.fs.s3a.fileContext;
 
+import java.net.URI;
+import java.net.URISyntaxException;
+
+import org.junit.Test;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileContext;
+import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.fs.TestFileContext;
+import org.apache.hadoop.fs.UnsupportedFileSystemException;
+
+import static org.junit.Assert.assertEquals;
 
 /**
  * Implementation of TestFileContext for S3a.
  */
-public class ITestS3AFileContext extends TestFileContext{
+public class ITestS3AFileContext extends TestFileContext {
 
+  @Test
+  public void testScheme()
+      throws URISyntaxException, UnsupportedFileSystemException {
+    Configuration conf = new Configuration();
+    URI uri = new URI("s3://mybucket/path");
+    conf.set("fs.AbstractFileSystem.s3.impl",
+        "org.apache.hadoop.fs.s3a.S3A");
+    FileContext fc = FileContext.getFileContext(uri, conf);
+    assertEquals("s3", fc.getDefaultFileSystem().getUri().getScheme());
+    Path path = fc.makeQualified(new Path("tmp/path"));
+    assertEquals("s3", path.toUri().getScheme());
+  }
 }