Enable smart HTTP under /p/ URLs

The new smart HTTP Git protocol is now supported through the Gerrit
web application context by using the URL /p/$project.git.

Like SSH, push requires user authentication.  However, since
user authentication is currently based solely upon HTTP cookies,
and cookies aren't supported by the C Git command line client,
using push is not currently possible.  We need to introduce our
own password based user authentication process.

Change-Id: I76a894226a583ce6f47fd246f7d0f88b77ea4505
Signed-off-by: Shawn O. Pearce <sop@google.com>

gerrit-httpd/pom.xml

@@ -38,6 +38,11 @@ limitations under the License.
       <artifactId>servlet-api</artifactId>
       <scope>provided</scope>
     </dependency>
+ 
+    <dependency>
+      <groupId>org.eclipse.jgit</groupId>
+      <artifactId>org.eclipse.jgit.http.server</artifactId>
+    </dependency>
 
     <dependency>
       <groupId>org.eclipse.jgit</groupId>

gerrit-httpd/src/main/java/com/google/gerrit/httpd/ProjectServlet.java

@@ -0,0 +1,210 @@
+// Copyright (C) 2010 The Android Open Source Project
+//
+// Licensed 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 com.google.gerrit.httpd;
+
+import com.google.gerrit.common.PageLinks;
+import com.google.gerrit.reviewdb.Change;
+import com.google.gerrit.reviewdb.Project;
+import com.google.gerrit.server.IdentifiedUser;
+import com.google.gerrit.server.config.CanonicalWebUrl;
+import com.google.gerrit.server.config.Nullable;
+import com.google.gerrit.server.git.GitRepositoryManager;
+import com.google.gerrit.server.git.ReceiveCommits;
+import com.google.gerrit.server.project.NoSuchProjectException;
+import com.google.gerrit.server.project.ProjectControl;
+import com.google.inject.AbstractModule;
+import com.google.inject.Inject;
+import com.google.inject.Provider;
+import com.google.inject.Singleton;
+
+import org.eclipse.jgit.errors.RepositoryNotFoundException;
+import org.eclipse.jgit.http.server.GitServlet;
+import org.eclipse.jgit.http.server.resolver.AsIsFileService;
+import org.eclipse.jgit.http.server.resolver.ReceivePackFactory;
+import org.eclipse.jgit.http.server.resolver.RepositoryResolver;
+import org.eclipse.jgit.http.server.resolver.ServiceNotAuthorizedException;
+import org.eclipse.jgit.http.server.resolver.ServiceNotEnabledException;
+import org.eclipse.jgit.http.server.resolver.UploadPackFactory;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.transport.ReceivePack;
+import org.eclipse.jgit.transport.UploadPack;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+
+import javax.servlet.ServletConfig;
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+/** Serves Git repositories over HTTP. */
+@Singleton
+public class ProjectServlet extends GitServlet {
+  private static final Logger log =
+      LoggerFactory.getLogger(ProjectServlet.class);
+
+  private static final String ATT_CONTROL = ProjectControl.class.getName();
+
+  static class Module extends AbstractModule {
+    @Override
+    protected void configure() {
+      bind(Resolver.class);
+      bind(Upload.class);
+      bind(Receive.class);
+    }
+  }
+
+  static ProjectControl getProjectControl(HttpServletRequest req)
+      throws ServiceNotEnabledException {
+    ProjectControl pc = (ProjectControl) req.getAttribute(ATT_CONTROL);
+    if (pc == null) {
+      log.error("No " + ATT_CONTROL + " in request", new Exception("here"));
+      throw new ServiceNotEnabledException();
+    }
+    return pc;
+  }
+
+  private final Provider<String> urlProvider;
+
+  @Inject
+  ProjectServlet(final Resolver resolver, final Upload upload,
+      final Receive receive,
+      @CanonicalWebUrl @Nullable Provider<String> urlProvider) {
+    this.urlProvider = urlProvider;
+
+    setRepositoryResolver(resolver);
+    setAsIsFileService(AsIsFileService.DISABLED);
+    setUploadPackFactory(upload);
+    setReceivePackFactory(receive);
+  }
+
+  @Override
+  public void init(ServletConfig config) throws ServletException {
+    super.init(config);
+
+    serveRegex("^/(.*?)/?$").with(new HttpServlet() {
+      @Override
+      protected void doGet(HttpServletRequest req, HttpServletResponse rsp)
+          throws IOException {
+        ProjectControl pc;
+        try {
+          pc = getProjectControl(req);
+        } catch (ServiceNotEnabledException e) {
+          rsp.sendError(HttpServletResponse.SC_NOT_FOUND);
+          return;
+        }
+
+        Project.NameKey dst = pc.getProject().getNameKey();
+        StringBuilder r = new StringBuilder();
+        r.append(urlProvider.get());
+        r.append('#');
+        r.append(PageLinks.toProject(dst, Change.Status.NEW));
+        rsp.sendRedirect(r.toString());
+      }
+    });
+  }
+
+  static class Resolver implements RepositoryResolver {
+    private final GitRepositoryManager manager;
+    private final ProjectControl.Factory projectControlFactory;
+
+    @Inject
+    Resolver(GitRepositoryManager manager,
+        ProjectControl.Factory projectControlFactory) {
+      this.manager = manager;
+      this.projectControlFactory = projectControlFactory;
+    }
+
+    @Override
+    public Repository open(HttpServletRequest req, String projectName)
+        throws RepositoryNotFoundException {
+      if (projectName.endsWith(".git")) {
+        // Be nice and drop the trailing ".git" suffix, which we never keep
+        // in our database, but clients might mistakenly provide anyway.
+        //
+        projectName = projectName.substring(0, projectName.length() - 4);
+      }
+
+      if (projectName.startsWith("/")) {
+        // Be nice and drop the leading "/" if supplied by an absolute path.
+        // We don't have a file system hierarchy, just a flat namespace in
+        // the database's Project entities. We never encode these with a
+        // leading '/' but users might accidentally include them in Git URLs.
+        //
+        projectName = projectName.substring(1);
+      }
+
+      final ProjectControl pc;
+      try {
+        final Project.NameKey nameKey = new Project.NameKey(projectName);
+        pc = projectControlFactory.validateFor(nameKey);
+      } catch (NoSuchProjectException err) {
+        throw new RepositoryNotFoundException(projectName);
+      }
+      req.setAttribute(ATT_CONTROL, pc);
+
+      return manager.openRepository(pc.getProject().getName());
+    }
+  }
+
+  static class Upload implements UploadPackFactory {
+    @Override
+    public UploadPack create(HttpServletRequest req, Repository db)
+        throws ServiceNotEnabledException {
+      // The Resolver above already checked READ access for us.
+      //
+      ProjectControl pc = getProjectControl(req);
+      UploadPack up = new UploadPack(db);
+      return up;
+    }
+  }
+
+  static class Receive implements ReceivePackFactory {
+    private final ReceiveCommits.Factory factory;
+
+    @Inject
+    Receive(final ReceiveCommits.Factory factory) {
+      this.factory = factory;
+    }
+
+    @Override
+    public ReceivePack create(HttpServletRequest req, Repository db)
+        throws ServiceNotEnabledException, ServiceNotAuthorizedException {
+      final ProjectControl pc = getProjectControl(req);
+      if (pc.getCurrentUser() instanceof IdentifiedUser) {
+        final IdentifiedUser user = (IdentifiedUser) pc.getCurrentUser();
+        final ReceiveCommits rc = factory.create(pc, db);
+        final ReceiveCommits.Capable s = rc.canUpload();
+        if (s != ReceiveCommits.Capable.OK) {
+          // TODO We should alert the user to this message on the HTTP
+          // response channel, assuming Git will even report it to them.
+          //
+          final String who = user.getUserName();
+          final String why = s.getMessage();
+          log.warn("Rejected push from " + who + ": " + why);
+          throw new ServiceNotEnabledException();
+        }
+
+        rc.getReceivePack().setRefLogIdent(user.newRefLogIdent());
+        return rc.getReceivePack();
+
+      } else {
+        throw new ServiceNotAuthorizedException();
+      }
+    }
+  }
+}

gerrit-httpd/src/main/java/com/google/gerrit/httpd/UrlModule.java

@@ -49,6 +49,7 @@ class UrlModule extends ServletModule {
     serve("/signout").with(HttpLogoutServlet.class);
     serve("/ssh_info").with(SshInfoServlet.class);
     serve("/static/*").with(StaticServlet.class);
+    serve("/p/*").with(ProjectServlet.class);
 
     serve("/Main.class").with(notFound());
     serve("/com/google/gerrit/launcher/*").with(notFound());

gerrit-httpd/src/main/java/com/google/gerrit/httpd/WebModule.java

@@ -118,6 +118,7 @@ public class WebModule extends FactoryModule {
     install(new UrlModule());
     install(new UiRpcModule());
     install(new GerritRequestModule());
+    install(new ProjectServlet.Module());
 
     bind(SshInfo.class).toProvider(sshInfoProvider);
     bind(SshKeyCache.class).toProvider(sshKeyCacheProvider);

pom.xml

@@ -632,6 +632,12 @@ limitations under the License.
         </exclusions>
       </dependency>
 
+      <dependency>
+        <groupId>org.eclipse.jgit</groupId>
+        <artifactId>org.eclipse.jgit.http.server</artifactId>
+        <version>${jgitVersion}</version>
+      </dependency>
+
       <dependency>
         <groupId>junit</groupId>
         <artifactId>junit</artifactId>