SshSupport.java
- /*
- * Copyright (C) 2018, Markus Duft <markus.duft@ssi-schaefer.com> and others
- *
- * This program and the accompanying materials are made available under the
- * terms of the Eclipse Distribution License v. 1.0 which is available at
- * https://www.eclipse.org/org/documents/edl-v10.php.
- *
- * SPDX-License-Identifier: BSD-3-Clause
- */
- package org.eclipse.jgit.util;
- import java.io.IOException;
- import java.text.MessageFormat;
- import java.util.concurrent.TimeUnit;
- import org.eclipse.jgit.annotations.Nullable;
- import org.eclipse.jgit.errors.CommandFailedException;
- import org.eclipse.jgit.internal.JGitText;
- import org.eclipse.jgit.transport.CredentialsProvider;
- import org.eclipse.jgit.transport.RemoteSession;
- import org.eclipse.jgit.transport.SshSessionFactory;
- import org.eclipse.jgit.transport.URIish;
- import org.eclipse.jgit.util.io.MessageWriter;
- import org.eclipse.jgit.util.io.StreamCopyThread;
- /**
- * Extra utilities to support usage of SSH.
- *
- * @since 5.0
- */
- public class SshSupport {
- /**
- * Utility to execute a remote SSH command and read the first line of
- * output.
- *
- * @param sshUri
- * the SSH remote URI
- * @param provider
- * the {@link CredentialsProvider} or <code>null</code>.
- * @param fs
- * the {@link FS} implementation passed to
- * {@link SshSessionFactory}
- * @param command
- * the remote command to execute.
- * @param timeout
- * a timeout in seconds. The timeout may be exceeded in corner
- * cases.
- * @return The entire output read from stdout.
- * @throws IOException
- * @throws CommandFailedException
- * if the ssh command execution failed, error message contains
- * the content of stderr.
- */
- public static String runSshCommand(URIish sshUri,
- @Nullable CredentialsProvider provider, FS fs, String command,
- int timeout) throws IOException, CommandFailedException {
- RemoteSession session = null;
- Process process = null;
- StreamCopyThread errorThread = null;
- StreamCopyThread outThread = null;
- CommandFailedException failure = null;
- @SuppressWarnings("resource")
- MessageWriter stderr = new MessageWriter();
- @SuppressWarnings("resource")
- MessageWriter stdout = new MessageWriter();
- String out;
- try {
- long start = System.nanoTime();
- session = SshSessionFactory.getInstance().getSession(sshUri,
- provider, fs, 1000 * timeout);
- int commandTimeout = timeout;
- if (timeout > 0) {
- commandTimeout = checkTimeout(command, timeout, start);
- }
- process = session.exec(command, commandTimeout);
- if (timeout > 0) {
- commandTimeout = checkTimeout(command, timeout, start);
- }
- errorThread = new StreamCopyThread(process.getErrorStream(),
- stderr.getRawStream());
- errorThread.start();
- outThread = new StreamCopyThread(process.getInputStream(),
- stdout.getRawStream());
- outThread.start();
- try {
- boolean finished = false;
- if (timeout <= 0) {
- process.waitFor();
- finished = true;
- } else {
- finished = process.waitFor(commandTimeout,
- TimeUnit.SECONDS);
- }
- if (finished) {
- out = stdout.toString();
- } else {
- out = null; // still running after timeout
- }
- } catch (InterruptedException e) {
- out = null; // error
- }
- } finally {
- if (errorThread != null) {
- try {
- errorThread.halt();
- } catch (InterruptedException e) {
- // Stop waiting and return anyway.
- } finally {
- errorThread = null;
- }
- }
- if (outThread != null) {
- try {
- outThread.halt();
- } catch (InterruptedException e) {
- // Stop waiting and return anyway.
- } finally {
- outThread = null;
- }
- }
- if (process != null) {
- try {
- if (process.exitValue() != 0) {
- failure = new CommandFailedException(
- process.exitValue(),
- MessageFormat.format(
- JGitText.get().sshCommandFailed,
- command, stderr.toString()));
- }
- // It was successful after all
- out = stdout.toString();
- } catch (IllegalThreadStateException e) {
- failure = new CommandFailedException(0,
- MessageFormat.format(
- JGitText.get().sshCommandTimeout, command,
- Integer.valueOf(timeout)));
- }
- process.destroy();
- }
- stderr.close();
- stdout.close();
- if (session != null) {
- SshSessionFactory.getInstance().releaseSession(session);
- }
- }
- if (failure != null) {
- throw failure;
- }
- return out;
- }
- private static int checkTimeout(String command, int timeout, long since)
- throws CommandFailedException {
- long elapsed = System.nanoTime() - since;
- int newTimeout = timeout
- - (int) TimeUnit.NANOSECONDS.toSeconds(elapsed);
- if (newTimeout <= 0) {
- // All time used up for connecting the session
- throw new CommandFailedException(0,
- MessageFormat.format(JGitText.get().sshCommandTimeout,
- command, Integer.valueOf(timeout)));
- }
- return newTimeout;
- }
- }