Wrong exception thrown when snapshot doesn't exist

As for elastic/elasticsearch-cloud-aws#86, we should raise a `SnapshotMissingException`.

Closes #23.

(cherry picked from commit 61ddb60)

Author: dadoonet

src/main/java/org/elasticsearch/cloud/azure/blobstore/AbstractAzureBlobContainer.java

@@ -30,6 +30,7 @@
 import org.elasticsearch.common.logging.ESLogger;
 import org.elasticsearch.common.logging.ESLoggerFactory;
 
+import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.URISyntaxException;
@@ -95,6 +96,12 @@ public void run() {
                 }
                 is.close();
                 listener.onCompleted();
+            } catch (ServiceException e) {
+                if (e.getHttpStatusCode() == 404) {
+                    listener.onFailure(new FileNotFoundException(e.getMessage()));
+                } else {
+                    listener.onFailure(e);
+                }
             } catch (Throwable e) {
                 IOUtils.closeWhileHandlingException(is);
                 listener.onFailure(e);

src/test/java/org/elasticsearch/repositories/azure/AzureSnapshotRestoreITest.java

@@ -35,6 +35,7 @@
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.repositories.RepositoryException;
 import org.elasticsearch.repositories.RepositoryMissingException;
+import org.elasticsearch.snapshots.SnapshotMissingException;
 import org.elasticsearch.snapshots.SnapshotState;
 import org.elasticsearch.test.ElasticsearchIntegrationTest;
 import org.elasticsearch.test.store.MockDirectoryHelper;
@@ -44,9 +45,7 @@
 
 import java.net.URISyntaxException;
 
-import static org.hamcrest.Matchers.equalTo;
-import static org.hamcrest.Matchers.greaterThan;
-import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.*;
 
 /**
  * This test needs Azure to run and -Dtests.azure=true to be set
@@ -268,6 +267,30 @@ private void checkContainerName(String container, boolean correct) {
         }
     }
 
+    /**
+     * Test case for issue #23: https://github.com/elasticsearch/elasticsearch-cloud-azure/issues/23
+     */
+    @Test
+    public void testNonExistingRepo_23() {
+        Client client = client();
+        logger.info("-->  creating azure repository with path [{}]", basePath);
+        PutRepositoryResponse putRepositoryResponse = client.admin().cluster().preparePutRepository("test-repo")
+                .setType("azure").setSettings(ImmutableSettings.settingsBuilder()
+                                .put(AzureStorageService.Fields.CONTAINER, "elasticsearch-integration")
+                                .put(AzureStorageService.Fields.BASE_PATH, basePath)
+                                .put(AzureStorageService.Fields.CHUNK_SIZE, randomIntBetween(1000, 10000))
+                ).get();
+        assertThat(putRepositoryResponse.isAcknowledged(), equalTo(true));
+
+        logger.info("--> restore non existing snapshot");
+        try {
+            client.admin().cluster().prepareRestoreSnapshot("test-repo", "no-existing-snapshot").setWaitForCompletion(true).execute().actionGet();
+            fail("Shouldn't be here");
+        } catch (SnapshotMissingException ex) {
+            // Expected
+        }
+    }
+
     /**
      * Deletes repositories, supports wildcard notation.
      */