joewitt commented on code in PR #8489: URL: https://github.com/apache/nifi/pull/8489#discussion_r1666265757
########## nifi-nar-bundles/nifi-standard-bundle/nifi-standard-processors/src/main/java/org/apache/nifi/processors/standard/DeleteFile.java: ########## @@ -0,0 +1,138 @@ +/* + * 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.standard; + +import org.apache.nifi.annotation.behavior.DefaultRunDuration; +import org.apache.nifi.annotation.behavior.InputRequirement; +import org.apache.nifi.annotation.behavior.SupportsBatching; +import org.apache.nifi.annotation.documentation.CapabilityDescription; +import org.apache.nifi.annotation.documentation.Tags; +import org.apache.nifi.annotation.documentation.UseCase; +import org.apache.nifi.components.PropertyDescriptor; +import org.apache.nifi.expression.ExpressionLanguageScope; +import org.apache.nifi.flowfile.FlowFile; +import org.apache.nifi.flowfile.attributes.CoreAttributes; +import org.apache.nifi.processor.AbstractProcessor; +import org.apache.nifi.processor.ProcessContext; +import org.apache.nifi.processor.ProcessSession; +import org.apache.nifi.processor.Relationship; +import org.apache.nifi.processor.exception.ProcessException; +import org.apache.nifi.processor.util.StandardValidators; + +import java.io.IOException; +import java.nio.file.Files; +import java.nio.file.NoSuchFileException; +import java.nio.file.Path; +import java.nio.file.Paths; +import java.util.List; +import java.util.Set; + +@SupportsBatching(defaultDuration = DefaultRunDuration.TWENTY_FIVE_MILLIS) +@InputRequirement(InputRequirement.Requirement.INPUT_REQUIRED) +@Tags({"file", "remove", "delete", "local", "files", "filesystem"}) +@CapabilityDescription("Deletes a file from the filesystem.") +@UseCase( + description = "Delete source file only after its processing completed", + configuration = """ + Retrieve a file from the filesystem, e.g. using 'ListFile' and 'FetchFile'. + Process the file using any combination of processors. + Store the resulting file to a destination, e.g. using 'PutSFTP'. + Using 'DeleteFile', delete the file from the filesystem only after the result has been stored. + """ +) +public class DeleteFile extends AbstractProcessor { + + public static final Relationship REL_SUCCESS = new Relationship.Builder() + .name("success") + .description("All FlowFiles, for which an existing file has been deleted, are routed to this relationship") + .build(); + public static final Relationship REL_NOT_FOUND = new Relationship.Builder() + .name("not found") + .description("All FlowFiles, for which the file to delete did not exist, are routed to this relationship") + .build(); + public static final Relationship REL_FAILURE = new Relationship.Builder() + .name("failure") + .description("All FlowFiles, for which an existing file could not be deleted, are routed to this relationship") + .build(); + + private final static Set<Relationship> relationships = Set.of(REL_SUCCESS, REL_NOT_FOUND, REL_FAILURE); + + public static final PropertyDescriptor DIRECTORY_PATH = new PropertyDescriptor.Builder() + .name("Directory Path") + .displayName("Directory Path") + .description("The path to the directory the file to delete is located in.") + .required(true) + .defaultValue("${" + CoreAttributes.ABSOLUTE_PATH.key() + "}") + .addValidator(StandardValidators.createDirectoryExistsValidator(true, false)) + .expressionLanguageSupported(ExpressionLanguageScope.FLOWFILE_ATTRIBUTES) + .build(); + public static final PropertyDescriptor FILENAME = new PropertyDescriptor.Builder() + .name("Filename") + .displayName("Filename") + .description("The name of the file to delete.") + .required(true) + .defaultValue("${" + CoreAttributes.FILENAME.key() + "}") + .addValidator(StandardValidators.NON_EMPTY_EL_VALIDATOR) + .expressionLanguageSupported(ExpressionLanguageScope.FLOWFILE_ATTRIBUTES) + .build(); + + private final static List<PropertyDescriptor> properties = List.of(DIRECTORY_PATH, FILENAME); + + @Override + public Set<Relationship> getRelationships() { + return relationships; + } + + @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 String directoryPathProperty = context.getProperty(DIRECTORY_PATH).evaluateAttributeExpressions(flowFile).getValue(); + final String filename = context.getProperty(FILENAME).evaluateAttributeExpressions(flowFile).getValue(); + + try { + final Path directoryPath = Paths.get(directoryPathProperty).toRealPath(); + final Path filePath = directoryPath.resolve(filename).toRealPath(); + + if (!directoryPath.equals(filePath.getParent())) { + getLogger().error("Attempting to delete file at path '{}' which is not a direct child of the directory '{}'", filePath, directoryPath); + session.penalize(flowFile); + session.transfer(flowFile, REL_FAILURE); + return; + } + + Files.delete(filePath); + + session.transfer(flowFile, REL_SUCCESS); + } catch (NoSuchFileException noSuchFileException) { + session.transfer(flowFile, REL_NOT_FOUND); + } catch (IOException ioException) { + getLogger().error("Failed to delete file '{}' in directory '{}'", filename, directoryPathProperty, ioException); + + session.penalize(flowFile); + session.transfer(flowFile, REL_FAILURE); Review Comment: @jrsteinebrey We should not start having a standard of writing exception class names in flowfile attributes nor should we make it a standard to have raw exception messages in an attribute. I certainly agree we can and should do more to provide more context to the user but doing it this way is not nearly as effective as the component/extension developer being thoughtful about which exceptions can occur and what would be best to convey to the user both in terms of what we log, what we may add as context in flowfile attributes, and what relatioships we give them to make different flow design decisions. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: issues-unsubscr...@nifi.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
