Auto-configure Gerrit after ssh clone

ConfigureGerritAfterCloneTask.isGerrit() only worked for HTTP(S)
cloning in general; for ssh cloning it worked only for git.eclipse.org.

Use the same approach as for HTTP also for SSH: invoke Gerrit's
"gerrit version" SSH endpoint and see what we get.

Bug: 474019
Change-Id: Ic97040add0e805f34ef00f194e2a34ad3011fdcf
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

2 files changed, 114 insertions, 10 deletions

diff --git a/org.eclipse.egit.core/src/org/eclipse/egit/core/op/ConfigureGerritAfterCloneTask.java b/org.eclipse.egit.core/src/org/eclipse/egit/core/op/ConfigureGerritAfterCloneTask.java
index 0a76a58a0c..43723255d3 100644
--- a/org.eclipse.egit.core/src/org/eclipse/egit/core/op/ConfigureGerritAfterCloneTask.java
+++ b/org.eclipse.egit.core/src/org/eclipse/egit/core/op/ConfigureGerritAfterCloneTask.java
@@ -1,5 +1,6 @@
 /*******************************************************************************
  * Copyright (C) 2015, Matthias Sohn <matthias.sohn@sap.com>
+ * Copyright (C) 2015, Thomas Wolf <thomas.wolf@paranor.ch>
  *
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
@@ -8,13 +9,16 @@
  *******************************************************************************/
 package org.eclipse.egit.core.op;
 
+import java.io.BufferedReader;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.InputStreamReader;
 import java.net.HttpURLConnection;
 import java.net.MalformedURLException;
 import java.net.URISyntaxException;
 import java.net.URL;
+import java.util.regex.Pattern;
 
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IProgressMonitor;
@@ -25,8 +29,14 @@ import org.eclipse.egit.core.op.CloneOperation.PostCloneTask;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.lib.StoredConfig;
+import org.eclipse.jgit.transport.CredentialsProvider;
 import org.eclipse.jgit.transport.RemoteConfig;
+import org.eclipse.jgit.transport.RemoteSession;
+import org.eclipse.jgit.transport.SshSessionFactory;
 import org.eclipse.jgit.transport.URIish;
+import org.eclipse.jgit.util.FS;
+import org.eclipse.jgit.util.io.MessageWriter;
+import org.eclipse.jgit.util.io.StreamCopyThread;
 
 /**
  * Configure Gerrit if repository was cloned from a Gerrit server
@@ -45,6 +55,29 @@ public class ConfigureGerritAfterCloneTask implements PostCloneTask {
 
 	private static final String GERRIT_CONFIG_SERVER_VERSION_API = "/config/server/version"; //$NON-NLS-1$
 
+	private static final int GERRIT_SSHD_DEFAULT_PORT = 29418;
+
+	private static final String GERRIT_SSHD_VERSION_API = "gerrit version"; //$NON-NLS-1$
+
+	/**
+	 * Pattern to match the sshd reply[1] against to determine whether it's a
+	 * Gerrit.
+	 * <p>
+	 * [1]<a href=
+	 * "https://gerrit-documentation.storage.googleapis.com/Documentation/2.11/cmd-version.html">
+	 * Gerrit 2.11 gerrit version ssh command</a>
+	 * </p>
+	 * <p>
+	 * We match the whole reply from Gerrit's sshd (as opposed to a prefix match
+	 * for "gerrit version") just in case a non-Gerrit has the great idea to
+	 * return an error message like "gerrit version: unknown command" or some
+	 * such on its stdout...
+	 * </p>
+	 */
+	private static final Pattern GERRIT_SSHD_REPLY = Pattern
+			.compile(GERRIT_SSHD_VERSION_API
+					+ "\\s+(?:\\d+(?:\\.\\d+)+|.+-\\d+-g[0-9a-fA-F]{7})"); //$NON-NLS-1$
+
 	/**
 	 * To prevent against Cross Site Script Inclusion (XSSI) attacks, the Gerrit
 	 * JSON response body starts with a magic prefix line we can use as a second
@@ -61,6 +94,8 @@ public class ConfigureGerritAfterCloneTask implements PostCloneTask {
 
 	private final String remoteName;
 
+	private final CredentialsProvider credentialsProvider;
+
 	private int timeout;
 
 	/**
@@ -68,14 +103,19 @@ public class ConfigureGerritAfterCloneTask implements PostCloneTask {
 	 *            not null
 	 * @param remoteName
 	 *            not null
+	 * @param credentialsProvider
+	 *            {@link CredentialsProvider} to use for remote communication;
+	 *            if {@code null} auto-configuration for repositories cloned
+	 *            over ssh will work only for git.eclipse.org
 	 * @param timeout
 	 *            timeout for remote communication in seconds
 	 */
 	public ConfigureGerritAfterCloneTask(String uri, String remoteName,
-			int timeout) {
+			CredentialsProvider credentialsProvider, int timeout) {
 		this.uri = uri;
 		this.remoteName = remoteName;
 		this.timeout = timeout;
+		this.credentialsProvider = credentialsProvider;
 	}
 
 	public void execute(Repository repository, IProgressMonitor monitor)
@@ -121,7 +161,8 @@ public class ConfigureGerritAfterCloneTask implements PostCloneTask {
 			if (HTTPS.equals(s) && (u.getPort() == 443 || u.getPort() == -1)
 					&& path != null && path.startsWith(GERRIT_CONTEXT_ROOT)) {
 				return true;
-			} else if (SSH.equals(s) && (u.getPort() == 29418)) {
+			} else
+				if (SSH.equals(s) && u.getPort() == GERRIT_SSHD_DEFAULT_PORT) {
 				return true;
 			}
 		}
@@ -178,6 +219,25 @@ public class ConfigureGerritAfterCloneTask implements PostCloneTask {
 					httpConnection.disconnect();
 				}
 			}
+		} else if (SSH.equals(s)) {
+			if (u.getPort() < 0 || u.getUser() == null
+					|| credentialsProvider == null) {
+				return false;
+			}
+			URIish sshUri = u.setPath(""); //$NON-NLS-1$
+			try {
+				String result = runSshCommand(sshUri, credentialsProvider,
+						repo.getFS(), GERRIT_SSHD_VERSION_API);
+				return result != null
+						&& GERRIT_SSHD_REPLY.matcher(result).matches();
+			} catch (IOException e) {
+				// Something went wrong with the connection or with the command
+				// execution. Maybe the server didn't recognize the command. Do
+				// the safe thing and claim it wasn't a Gerrit. In the worst
+				// case, the user may have to do the Gerrit config setup via
+				// the ConfigureGerritWizard.
+				return false;
+			}
 		}
 		return false;
 	}
@@ -213,4 +273,40 @@ public class ConfigureGerritAfterCloneTask implements PostCloneTask {
 		config.save();
 	}
 
+	private String runSshCommand(URIish sshUri, CredentialsProvider provider,
+			FS fs, String command) throws IOException {
+		RemoteSession session = null;
+		Process process = null;
+		StreamCopyThread errorThread = null;
+		try (MessageWriter stderr = new MessageWriter()) {
+			session = SshSessionFactory.getInstance().getSession(sshUri,
+					provider, fs, 1000 * timeout);
+			process = session.exec(command, 0);
+			errorThread = new StreamCopyThread(process.getErrorStream(),
+					stderr.getRawStream());
+			errorThread.start();
+			try (BufferedReader reader = new BufferedReader(
+					new InputStreamReader(process.getInputStream(),
+							Constants.CHARSET))) {
+				return reader.readLine();
+			}
+		} finally {
+			if (errorThread != null) {
+				try {
+					errorThread.halt();
+				} catch (InterruptedException e) {
+					// Stop waiting and return anyway.
+				} finally {
+					errorThread = null;
+				}
+			}
+			if (process != null) {
+				process.destroy();
+			}
+			if (session != null) {
+				SshSessionFactory.getInstance().releaseSession(session);
+			}
+		}
+	}
+
 }
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/clone/AbstractGitCloneWizard.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/clone/AbstractGitCloneWizard.java
index b1c53431e5..49ff1d1777 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/clone/AbstractGitCloneWizard.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/clone/AbstractGitCloneWizard.java
@@ -61,6 +61,7 @@ import org.eclipse.jface.wizard.Wizard;
 import org.eclipse.jface.wizard.WizardPage;
 import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.transport.CredentialsProvider;
 import org.eclipse.jgit.transport.URIish;
 import org.eclipse.osgi.util.NLS;
 import org.eclipse.ui.IWorkingSet;
@@ -245,17 +246,21 @@ public abstract class AbstractGitCloneWizard extends Wizard {
 		final CloneOperation op = new CloneOperation(uri, allSelected,
 				selectedBranches, workdir, ref != null ? ref.getName() : null,
 				remoteName, timeout);
-		if (credentials != null)
-			op.setCredentialsProvider(new EGitCredentialsProvider(
-					credentials.getUser(), credentials.getPassword()));
-		else
-			op.setCredentialsProvider(new EGitCredentialsProvider());
+		CredentialsProvider credentialsProvider = null;
+		if (credentials != null) {
+			credentialsProvider = new EGitCredentialsProvider(
+					credentials.getUser(), credentials.getPassword());
+		} else {
+			credentialsProvider = new EGitCredentialsProvider();
+		}
+		op.setCredentialsProvider(credentialsProvider);
 		op.setCloneSubmodules(cloneDestination.isCloneSubmodules());
 
 		configureFetchSpec(op, gitRepositoryInfo, remoteName);
 		configurePush(op, gitRepositoryInfo, remoteName);
 		configureRepositoryConfig(op, gitRepositoryInfo);
-		configureGerrit(op, gitRepositoryInfo, remoteName, timeout);
+		configureGerrit(op, gitRepositoryInfo, credentialsProvider, remoteName,
+				timeout);
 
 		if (cloneDestination.isImportProjects()) {
 			final IWorkingSet[] sets = cloneDestination.getWorkingSets();
@@ -349,9 +354,12 @@ public abstract class AbstractGitCloneWizard extends Wizard {
 	}
 
 	private void configureGerrit(CloneOperation op,
-			GitRepositoryInfo gitRepositoryInfo, String remoteName, int timeout) {
+			GitRepositoryInfo gitRepositoryInfo,
+			CredentialsProvider credentialsProvider, String remoteName,
+			int timeout) {
 		ConfigureGerritAfterCloneTask task = new ConfigureGerritAfterCloneTask(
-				gitRepositoryInfo.getCloneUri(), remoteName, timeout);
+				gitRepositoryInfo.getCloneUri(), remoteName,
+				credentialsProvider, timeout);
 		op.addPostCloneTask(task);
 	}