HADOOP-18820. ITestS3AAWSCredentialsProvider enhancements

* use intercept() and InstantiationIOException where appropriate.
* change method names to distinguish them better.
* add test to verify that the static create() method is called.

Change-Id: I88e6c4eed6153861b6bd83300e6c484eb4dda08e

Author: steveloughran

hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/ITestS3AAWSCredentialsProvider.java

@@ -27,8 +27,8 @@
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.fs.s3a.impl.InstantiationIOException;
-import org.apache.hadoop.test.GenericTestUtils;
 
+import org.assertj.core.api.Assertions;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.Timeout;
@@ -43,10 +43,13 @@
 import static org.apache.hadoop.fs.s3a.S3ATestUtils.getCSVTestPath;
 import static org.apache.hadoop.fs.s3a.S3ATestUtils.removeBaseAndBucketOverrides;
 import static org.apache.hadoop.fs.s3a.auth.delegation.DelegationConstants.DELEGATION_TOKEN_BINDING;
+import static org.apache.hadoop.fs.s3a.impl.InstantiationIOException.CONSTRUCTOR_EXCEPTION;
+import static org.apache.hadoop.test.LambdaTestUtils.intercept;
 import static org.junit.Assert.*;
 
 /**
- * Integration tests for {@link Constants#AWS_CREDENTIALS_PROVIDER} logic.
+ * Integration tests for {@link Constants#AWS_CREDENTIALS_PROVIDER} logic
+ * through the S3A Filesystem instantiation process.
  */
 public class ITestS3AAWSCredentialsProvider {
   private static final Logger LOG =
@@ -55,32 +58,36 @@ public class ITestS3AAWSCredentialsProvider {
   @Rule
   public Timeout testTimeout = new Timeout(60_1000, TimeUnit.MILLISECONDS);
 
+  /**
+   * Expecting a wrapped ClassNotFoundException.
+   */
   @Test
-  public void testBadConfiguration() throws IOException {
-    Configuration conf = createConf();
-    conf.set(AWS_CREDENTIALS_PROVIDER, "no.such.class");
-    try {
-      createFailingFS(conf);
-    } catch (IOException e) {
-      if (!(e.getCause() instanceof ClassNotFoundException)) {
-        LOG.error("Unexpected nested cause: {} in {}", e.getCause(), e, e);
-        throw e;
-      }
+  public void testProviderClassNotFound() throws Exception {
+    Configuration conf = createConf("no.such.class");
+    final InstantiationIOException e =
+        intercept(InstantiationIOException.class, "java.lang.ClassNotFoundException", () ->
+            createFailingFS(conf));
+    if (InstantiationIOException.Kind.InstantiationFailure != e.getKind()) {
+      throw e;
+    }
+    if (!(e.getCause() instanceof ClassNotFoundException)) {
+      LOG.error("Unexpected nested cause: {} in {}", e.getCause(), e, e);
+      throw e;
     }
   }
 
   /**
    * A bad CredentialsProvider which has no suitable constructor.
    *
    * This class does not provide a public constructor accepting Configuration,
-   * or a public factory method named getInstance that accepts no arguments,
+   * or a public factory method named create() that accepts no arguments,
    * or a public default constructor.
    */
-  static class BadCredentialsProviderConstructor
+  public static class BadCredentialsProviderConstructor
       implements AwsCredentialsProvider {
 
     @SuppressWarnings("unused")
-    BadCredentialsProviderConstructor(String fsUri, Configuration conf) {
+    public BadCredentialsProviderConstructor(String fsUri, Configuration conf) {
     }
 
     @Override
@@ -92,40 +99,60 @@ public AwsCredentials resolveCredentials() {
 
   @Test
   public void testBadCredentialsConstructor() throws Exception {
-    Configuration conf = createConf();
-    conf.set(AWS_CREDENTIALS_PROVIDER,
-        BadCredentialsProviderConstructor.class.getName());
-    try {
-      createFailingFS(conf);
-    } catch (IOException e) {
-      GenericTestUtils.assertExceptionContains(InstantiationIOException.CONSTRUCTOR_EXCEPTION, e);
+    Configuration conf = createConf(BadCredentialsProviderConstructor.class);
+    final InstantiationIOException ex =
+        intercept(InstantiationIOException.class, CONSTRUCTOR_EXCEPTION, () ->
+            createFailingFS(conf));
+    if (InstantiationIOException.Kind.UnsupportedConstructor != ex.getKind()) {
+      throw ex;
     }
   }
 
-  protected Configuration createConf() {
+  /**
+   * Create a configuration bonded to the given provider classname.
+   * @param provider provider to bond to
+   * @return a configuration
+   */
+  protected Configuration createConf(String provider) {
     Configuration conf = new Configuration();
     removeBaseAndBucketOverrides(conf,
         DELEGATION_TOKEN_BINDING,
         AWS_CREDENTIALS_PROVIDER);
+    conf.set(AWS_CREDENTIALS_PROVIDER, provider);
+    conf.set(DELEGATION_TOKEN_BINDING, "");
     return conf;
   }
 
+  /**
+   * Create a configuration bonded to the given provider class.
+   * @param provider provider to bond to
+   * @return a configuration
+   */
+  protected Configuration createConf(Class provider) {
+    return createConf(provider.getName());
+  }
+
   /**
    * Create a filesystem, expect it to fail by raising an IOException.
    * Raises an assertion exception if in fact the FS does get instantiated.
+   * The FS is always deleted.
    * @param conf configuration
    * @throws IOException an expected exception.
    */
   private void createFailingFS(Configuration conf) throws IOException {
-    S3AFileSystem fs = S3ATestUtils.createTestFileSystem(conf);
-    fs.listStatus(new Path("/"));
-    fail("Expected exception - got " + fs);
+    try(S3AFileSystem fs = S3ATestUtils.createTestFileSystem(conf)) {
+      fs.listStatus(new Path("/"));
+      fail("Expected exception - got " + fs);
+    }
   }
 
-  static class BadCredentialsProvider implements AwsCredentialsProvider {
+  /**
+   * Returns an invalid set of credentials.
+   */
+  public static class BadCredentialsProvider implements AwsCredentialsProvider {
 
     @SuppressWarnings("unused")
-    BadCredentialsProvider(Configuration conf) {
+    public BadCredentialsProvider(Configuration conf) {
     }
 
     @Override
@@ -137,34 +164,60 @@ public AwsCredentials resolveCredentials() {
 
   @Test
   public void testBadCredentials() throws Exception {
-    Configuration conf = new Configuration();
-    conf.set(AWS_CREDENTIALS_PROVIDER, BadCredentialsProvider.class.getName());
-    try {
-      createFailingFS(conf);
-    } catch (AccessDeniedException e) {
-      // expected
-    } catch (AWSServiceIOException e) {
-      GenericTestUtils.assertExceptionContains(
-          "UnrecognizedClientException", e);
-      // expected
-    }
+    Configuration conf = createConf(BadCredentialsProvider.class);
+    intercept(AccessDeniedException.class, "", () ->
+        createFailingFS(conf));
   }
 
+  /**
+   * Test using the anonymous credential provider with the public csv
+   * test file; if the test file path is unset then it will be skipped.
+   */
   @Test
   public void testAnonymousProvider() throws Exception {
-    Configuration conf = new Configuration();
-    conf.set(AWS_CREDENTIALS_PROVIDER,
-        AnonymousAWSCredentialsProvider.class.getName());
+    Configuration conf = createConf(AnonymousAWSCredentialsProvider.class);
     Path testFile = getCSVTestPath(conf);
     try (FileSystem fs = FileSystem.newInstance(testFile.toUri(), conf)) {
-      assertNotNull("S3AFileSystem instance must not be null", fs);
-      assertTrue("FileSystem must be the instance of S3AFileSystem", fs instanceof S3AFileSystem);
+      Assertions.assertThat(fs)
+          .describedAs("Filesystem")
+          .isNotNull();
       FileStatus stat = fs.getFileStatus(testFile);
-      assertNotNull("FileStatus with qualified path must not be null", stat);
       assertEquals(
           "The qualified path returned by getFileStatus should be same as the original file",
           testFile, stat.getPath());
     }
   }
 
+  /**
+   * Create credentials via the create() method.
+   * They are invalid credentials, so IO will fail as access denied.
+   */
+  @Test
+  public void testCredentialsWithCreateMethod() throws Exception {
+    Configuration conf = createConf(CredentialsProviderWithCreateMethod.class);
+    intercept(AccessDeniedException.class, "", () ->
+        createFailingFS(conf));
+  }
+
+  /**
+   * Credentials via the create() method.
+   */
+  public static class CredentialsProviderWithCreateMethod implements AwsCredentialsProvider {
+
+    public static AwsCredentialsProvider create() {
+      LOG.info("creating CredentialsProviderWithCreateMethod");
+      return new CredentialsProviderWithCreateMethod();
+    }
+
+    /** Private: cannot be created directly. */
+    private CredentialsProviderWithCreateMethod() {
+    }
+
+    @Override
+    public AwsCredentials resolveCredentials() {
+      return AwsBasicCredentials.create("bad_key", "bad_secret");
+    }
+
+  }
+
 }