Propagate failure of ssh command to caller of SshSupport

When SshSupport.runSshCommand fails since the executed external ssh
command failed throw a CommandFailedException.

If discovery of LFS server fails due to failure of the
git-lfs-authenticate command chain the CommandFailureException to the
LfsConfigInvalidException in order to allow root cause analysis in the
application using that.

Change-Id: I2f9ea2be11274549f6d845937164c248b3d840b2
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit.lfs/resources/org/eclipse/jgit/lfs/internal/LfsText.properties

@@ -1,4 +1,3 @@
-cannotDiscoverLfs=Cannot discover LFS URI
 corruptLongObject=The content hash ''{0}'' of the long object ''{1}'' doesn''t match its id, the corrupt object will be deleted.
 incorrectLONG_OBJECT_ID_LENGTH=Incorrect LONG_OBJECT_ID_LENGTH.
 inconsistentMediafileLength=Mediafile {0} has unexpected length; expected {1} but found {2}.

org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/errors/LfsConfigInvalidException.java

@@ -63,4 +63,17 @@ public class LfsConfigInvalidException extends IOException {
 		super(msg);
 	}
 
+	/**
+	 * Constructor for LfsConfigInvalidException.
+	 *
+	 * @param msg
+	 *            the error description
+	 * @param e
+	 *            cause of this exception
+	 * @since 5.0
+	 */
+	public LfsConfigInvalidException(String msg, Exception e) {
+		super(msg, e);
+	}
+
 }

org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/internal/LfsConnectionFactory.java

@@ -49,6 +49,7 @@ import static org.eclipse.jgit.util.HttpSupport.HDR_CONTENT_TYPE;
 
 import java.io.IOException;
 import java.net.ProxySelector;
+import java.net.URISyntaxException;
 import java.net.URL;
 import java.text.SimpleDateFormat;
 import java.util.LinkedList;
@@ -56,6 +57,7 @@ import java.util.Map;
 import java.util.TreeMap;
 
 import org.eclipse.jgit.annotations.NonNull;
+import org.eclipse.jgit.errors.CommandFailedException;
 import org.eclipse.jgit.lfs.LfsPointer;
 import org.eclipse.jgit.lfs.Protocol;
 import org.eclipse.jgit.lfs.errors.LfsConfigInvalidException;
@@ -68,17 +70,12 @@ import org.eclipse.jgit.transport.URIish;
 import org.eclipse.jgit.transport.http.HttpConnection;
 import org.eclipse.jgit.util.HttpSupport;
 import org.eclipse.jgit.util.SshSupport;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 /**
  * Provides means to get a valid LFS connection for a given repository.
  */
 public class LfsConnectionFactory {
 
-	private static final Logger log = LoggerFactory
-			.getLogger(LfsConnectionFactory.class);
-
 	private static final int SSH_AUTH_TIMEOUT_SECONDS = 30;
 	private static final String SCHEME_HTTPS = "https"; //$NON-NLS-1$
 	private static final String SCHEME_SSH = "ssh"; //$NON-NLS-1$
@@ -133,6 +130,7 @@ public class LfsConnectionFactory {
 		String lfsUrl = config.getString(ConfigConstants.CONFIG_SECTION_LFS,
 				null,
 				ConfigConstants.CONFIG_KEY_URL);
+		Exception ex = null;
 		if (lfsUrl == null) {
 			String remoteUrl = null;
 			for (String remote : db.getRemoteNames()) {
@@ -151,39 +149,44 @@ public class LfsConnectionFactory {
 				break;
 			}
 			if (lfsUrl == null && remoteUrl != null) {
+				try {
 					lfsUrl = discoverLfsUrl(db, purpose, additionalHeaders,
 							remoteUrl);
+				} catch (URISyntaxException | IOException
+						| CommandFailedException e) {
+					ex = e;
+				}
 			} else {
 				lfsUrl = lfsUrl + Protocol.INFO_LFS_ENDPOINT;
 			}
 		}
 		if (lfsUrl == null) {
+			if (ex != null) {
+				throw new LfsConfigInvalidException(
+						LfsText.get().lfsNoDownloadUrl, ex);
+			}
 			throw new LfsConfigInvalidException(LfsText.get().lfsNoDownloadUrl);
 		}
 		return lfsUrl;
 	}
 
 	private static String discoverLfsUrl(Repository db, String purpose,
-			Map<String, String> additionalHeaders, String remoteUrl) {
-		try {
+			Map<String, String> additionalHeaders, String remoteUrl)
+			throws URISyntaxException, IOException, CommandFailedException {
 		URIish u = new URIish(remoteUrl);
 		if (u.getScheme() == null || SCHEME_SSH.equals(u.getScheme())) {
-				Protocol.ExpiringAction action = getSshAuthentication(
-						db, purpose, remoteUrl, u);
+			Protocol.ExpiringAction action = getSshAuthentication(db, purpose,
+					remoteUrl, u);
 			additionalHeaders.putAll(action.header);
 			return action.href;
 		} else {
 			return remoteUrl + Protocol.INFO_LFS_ENDPOINT;
 		}
-		} catch (Exception e) {
-			log.error(LfsText.get().cannotDiscoverLfs, e);
-			return null; // could not discover
-		}
 	}
 
 	private static Protocol.ExpiringAction getSshAuthentication(
 			Repository db, String purpose, String remoteUrl, URIish u)
-			throws IOException {
+			throws IOException, CommandFailedException {
 		AuthCache cached = sshAuthCache.get(remoteUrl);
 		Protocol.ExpiringAction action = null;
 		if (cached != null && cached.validUntil > System.currentTimeMillis()) {

org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/internal/LfsText.java

@@ -60,7 +60,6 @@ public class LfsText extends TranslationBundle {
 	}
 
 	// @formatter:off
-	/***/ public String cannotDiscoverLfs;
 	/***/ public String corruptLongObject;
 	/***/ public String inconsistentMediafileLength;
 	/***/ public String inconsistentContentLength;

org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties

@@ -629,6 +629,7 @@ sourceIsNotAWildcard=Source is not a wildcard.
 sourceRefDoesntResolveToAnyObject=Source ref {0} doesn''t resolve to any object.
 sourceRefNotSpecifiedForRefspec=Source ref not specified for refspec: {0}
 squashCommitNotUpdatingHEAD=Squash commit -- not updating HEAD
+sshCommandFailed=Execution of ssh command ''{0}'' failed with error ''{1}''
 sshUserNameError=Jsch error: failed to set SSH user name correctly to ''{0}''; using ''{1}'' picked up from SSH config file.
 sslFailureExceptionMessage=Secure connection to {0} could not be stablished because of SSL problems
 sslFailureInfo=A secure connection to {0}\ncould not be established because the server''s certificate could not be validated.

org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java

@@ -690,6 +690,7 @@ public class JGitText extends TranslationBundle {
 	/***/ public String sourceRefDoesntResolveToAnyObject;
 	/***/ public String sourceRefNotSpecifiedForRefspec;
 	/***/ public String squashCommitNotUpdatingHEAD;
+	/***/ public String sshCommandFailed;
 	/***/ public String sshUserNameError;
 	/***/ public String sslFailureExceptionMessage;
 	/***/ public String sslFailureInfo;

org.eclipse.jgit/src/org/eclipse/jgit/util/SshSupport.java

@@ -43,8 +43,11 @@
 package org.eclipse.jgit.util;
 
 import java.io.IOException;
+import java.text.MessageFormat;
 
 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;
@@ -75,18 +78,23 @@ public class SshSupport {
 	 * @param timeout
 	 *            a timeout in seconds. The timeout may be exceeded in corner
 	 *            cases.
-	 * @return The entire output read from stdout. Stderr is discarded.
+	 * @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 {
+			int timeout) throws IOException, CommandFailedException {
 		RemoteSession session = null;
 		Process process = null;
 		StreamCopyThread errorThread = null;
 		StreamCopyThread outThread = null;
-		try (MessageWriter stderr = new MessageWriter();
-				MessageWriter stdout = new MessageWriter()) {
+		CommandFailedException failure = null;
+		@SuppressWarnings("resource")
+		MessageWriter stderr = new MessageWriter();
+		try (MessageWriter stdout = new MessageWriter()) {
 			session = SshSessionFactory.getInstance().getSession(sshUri,
 					provider, fs, 1000 * timeout);
 			process = session.exec(command, 0);
@@ -127,11 +135,21 @@ public class SshSupport {
 				}
 			}
 			if (process != null) {
+				if (process.exitValue() != 0) {
+					failure = new CommandFailedException(process.exitValue(),
+							MessageFormat.format(
+							JGitText.get().sshCommandFailed, command,
+							stderr.toString()));
+				}
 				process.destroy();
 			}
+			stderr.close();
 			if (session != null) {
 				SshSessionFactory.getInstance().releaseSession(session);
 			}
+			if (failure != null) {
+				throw failure;
+			}
 		}
 	}