alopresto commented on a change in pull request #3495: NIFI-5973 Adds ShellUserGroupProvider URL: https://github.com/apache/nifi/pull/3495#discussion_r290576353
########## File path: nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-shell-authorizer/src/main/java/org/apache/nifi/authorization/util/ShellRunner.java ########## @@ -0,0 +1,75 @@ +/* + * 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.authorization.util; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.io.BufferedReader; +import java.io.IOException; +import java.io.InputStreamReader; +import java.io.Reader; + +import java.util.ArrayList; +import java.util.List; +import java.util.concurrent.TimeUnit; + +public class ShellRunner { + private final static Logger logger = LoggerFactory.getLogger(ShellRunner.class); + + static String SHELL = "bash"; + static String OPTS = "-c"; + static Integer TIMEOUT = 30; + + public static List<String> runShell(String command) throws IOException { + final ProcessBuilder builder = new ProcessBuilder(SHELL, OPTS, command); + final List<String> builderCommand = builder.command(); + + logger.debug("Starting command: " + builderCommand + ", with timeout: " + TIMEOUT); + final Process proc = builder.start(); + logger.debug("Started command: " + builderCommand); + + try { + proc.waitFor(TIMEOUT, TimeUnit.SECONDS); + } catch (InterruptedException irexc) { + throw new IOException(irexc.getMessage(), irexc.getCause()); + } + + if (proc.exitValue() != 0) { + try (final Reader stderr = new InputStreamReader(proc.getErrorStream()); + final BufferedReader reader = new BufferedReader(stderr)) { + String line; + while ((line = reader.readLine()) != null) { + logger.debug("" + line.trim()); Review comment: Is prepending with `""` used to perform type conversion? I believe [`String#trim()`](https://docs.oracle.com/javase/8/docs/api/java/lang/String.html#trim()) always returns a valid `String` (if the result becomes empty, it returns a new empty String object). ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
