Github user brosander commented on a diff in the pull request:
https://github.com/apache/nifi/pull/1719#discussion_r114168730
--- Diff:
nifi-nar-bundles/nifi-azure-bundle/nifi-azure-processors/src/main/java/org/apache/nifi/processors/azure/storage/FetchAzureBlobStorage.java
---
@@ -0,0 +1,112 @@
+/*
+ * 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.nifi.processors.azure.storage;
+
+import java.io.IOException;
+import java.net.URISyntaxException;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.TimeUnit;
+
+import org.apache.nifi.annotation.behavior.InputRequirement;
+import org.apache.nifi.annotation.behavior.WritesAttribute;
+import org.apache.nifi.annotation.behavior.InputRequirement.Requirement;
+import org.apache.nifi.annotation.behavior.WritesAttributes;
+import org.apache.nifi.annotation.documentation.CapabilityDescription;
+import org.apache.nifi.annotation.documentation.SeeAlso;
+import org.apache.nifi.annotation.documentation.Tags;
+import org.apache.nifi.components.PropertyDescriptor;
+import org.apache.nifi.flowfile.FlowFile;
+import org.apache.nifi.processor.ProcessContext;
+import org.apache.nifi.processor.ProcessSession;
+import org.apache.nifi.processor.exception.ProcessException;
+import org.apache.nifi.processors.azure.AbstractAzureBlobProcessor;
+import org.apache.nifi.processors.azure.AzureConstants;
+
+import com.microsoft.azure.storage.CloudStorageAccount;
+import com.microsoft.azure.storage.StorageException;
+import com.microsoft.azure.storage.blob.CloudBlob;
+import com.microsoft.azure.storage.blob.CloudBlobClient;
+import com.microsoft.azure.storage.blob.CloudBlobContainer;
+
+@Tags({ "azure", "microsoft", "cloud", "storage", "blob" })
+@CapabilityDescription("Retrieves contents of an Azure Storage Blob,
writing the contents to the content of the FlowFile")
+@SeeAlso({ ListAzureBlobStorage.class, PutAzureBlobStorage.class })
+@InputRequirement(Requirement.INPUT_REQUIRED)
+@WritesAttributes({
+ @WritesAttribute(attribute = "azure.length", description = "The length
of the blob fetched")
+})
+public class FetchAzureBlobStorage extends AbstractAzureBlobProcessor {
+
+ private static final List<PropertyDescriptor> PROPERTIES = Collections
+ .unmodifiableList(Arrays.asList(AzureConstants.ACCOUNT_NAME,
AzureConstants.ACCOUNT_KEY, AzureConstants.CONTAINER, BLOB));
+
+ @Override
+ protected List<PropertyDescriptor> getSupportedPropertyDescriptors() {
+ return PROPERTIES;
+ }
+
+ @Override
+ public void onTrigger(ProcessContext context, ProcessSession session)
throws ProcessException {
+ FlowFile flowFile = session.get();
+ if (flowFile == null) {
+ return;
+ }
+
+ final long startNanos = System.nanoTime();
+
+ String containerName =
context.getProperty(AzureConstants.CONTAINER).evaluateAttributeExpressions(flowFile).getValue();
+ String blobPath =
context.getProperty(BLOB).evaluateAttributeExpressions(flowFile).getValue();
+
+ try {
+ CloudStorageAccount storageAccount =
createStorageConnection(context, flowFile);
+ CloudBlobClient blobClient =
storageAccount.createCloudBlobClient();
+ CloudBlobContainer container =
blobClient.getContainerReference(containerName);
+
+ final Map<String, String> attributes = new HashMap<>();
+ final CloudBlob blob =
container.getBlockBlobReference(blobPath);
+
+ // TODO - we may be able do fancier things with ranges and
+ // distribution of download over threads, investigate
+ flowFile = session.write(flowFile, os -> {
+ try {
+ blob.download(os);
+ } catch (StorageException e) {
+ throw new IOException(e);
--- End diff --
Since we wrap the StorageException in an IOException here, we should
probably add it to the catch block below or use an AtomicReference to propagate
it instead of wrapping in an IOE. When I deliberately used a blob name that
didn't exist, it didn't get routed to failure but instead was retried over and
over.
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