simonbence commented on a change in pull request #5059: URL: https://github.com/apache/nifi/pull/5059#discussion_r632378409
########## File path: nifi-nar-bundles/nifi-hadoop-bundle/nifi-hdfs-processors/src/main/java/org/apache/nifi/nar/hadoop/HDFSNarProvider.java ########## @@ -0,0 +1,231 @@ +/* + * 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.nar.hadoop; + +import org.apache.commons.io.IOUtils; +import org.apache.hadoop.conf.Configuration; +import org.apache.hadoop.fs.FSDataInputStream; +import org.apache.hadoop.fs.FileStatus; +import org.apache.hadoop.fs.FileSystem; +import org.apache.hadoop.fs.Path; +import org.apache.hadoop.net.NetUtils; +import org.apache.hadoop.security.UserGroupInformation; +import org.apache.nifi.hadoop.SecurityUtil; +import org.apache.nifi.nar.NarProvider; +import org.apache.nifi.nar.NarProviderInitializationContext; +import org.apache.nifi.nar.hadoop.util.ExtensionFilter; +import org.apache.nifi.processors.hadoop.ExtendedConfiguration; +import org.apache.nifi.processors.hadoop.HdfsResources; +import org.apache.nifi.security.krb.KerberosKeytabUser; +import org.apache.nifi.security.krb.KerberosPasswordUser; +import org.apache.nifi.security.krb.KerberosUser; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import javax.net.SocketFactory; +import java.io.IOException; +import java.io.InputStream; +import java.net.InetSocketAddress; +import java.net.Socket; +import java.net.URI; +import java.security.PrivilegedExceptionAction; +import java.util.Arrays; +import java.util.Collection; +import java.util.List; +import java.util.Objects; +import java.util.stream.Collectors; + +public class HDFSNarProvider implements NarProvider { + private static final Logger LOGGER = LoggerFactory.getLogger(HDFSNarProvider.class); + + private static final String RESOURCES_PARAMETER = "resources"; + private static final String SOURCE_DIRECTORY_PARAMETER = "source.directory"; + private static final String KERBEROS_PRINCIPAL_PARAMETER = "kerberos.principal"; + private static final String KERBEROS_KEYTAB_PARAMETER = "kerberos.keytab"; + private static final String KERBEROS_PASSWORD_PARAMETER = "kerberos.password"; + + private static final String NAR_EXTENSION = "nar"; + private static final String DELIMITER = "/"; + private static final int BUFFER_SIZE_DEFAULT = 4096; + private static final Object RESOURCES_LOCK = new Object(); + + private volatile List<String> resources = null; + private volatile Path sourceDirectory = null; + + private volatile NarProviderInitializationContext context; + + private volatile boolean initialized = false; + + public void initialize(final NarProviderInitializationContext context) { + resources = Arrays.stream(Objects.requireNonNull(context.getParameters().get(RESOURCES_PARAMETER)).split(",")).map(s -> s.trim()).collect(Collectors.toList()); + + if (resources.isEmpty()) { + throw new IllegalArgumentException("At least one HDFS configuration resource is necessary"); + } + + this.sourceDirectory = new Path(Objects.requireNonNull(context.getParameters().get(SOURCE_DIRECTORY_PARAMETER))); + this.context = context; + this.initialized = true; + } + + @Override + public Collection<String> listNars() throws IOException { + if (!initialized) { + LOGGER.error("Provider is not initialized"); + } + + final HdfsResources hdfsResources = getHdfsResources(); + final FileStatus[] fileStatuses = hdfsResources.getFileSystem().listStatus(sourceDirectory, new ExtensionFilter(NAR_EXTENSION)); + + final List<String> result = Arrays.stream(fileStatuses) + .filter(fileStatus -> fileStatus.isFile()) + .map(fileStatus -> fileStatus.getPath().getName()) + .collect(Collectors.toList()); + + if (LOGGER.isDebugEnabled()) { + LOGGER.debug("The following nars were found: " + String.join(", ", result)); + } + + return result; + } + + @Override + public InputStream fetchNarContents(final String location) throws IOException { + if (!initialized) { + LOGGER.error("Provider is not initialized"); + } + + + final Path path = getNarLocation(location); + final HdfsResources hdfsResources = getHdfsResources(); + + if (!hdfsResources.getFileSystem().exists(path)) { Review comment: I got this from `GetHDFS#performListing` which looks missing this, but now that I double check, it is wrapped in other places. -- This is an automated message from the Apache Git Service. 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