Configure database from gerrit.config

Instead of relying on the horribly ugly GerritServer.properties we
now configure the database out of gerrit.config through database.*
configuration settings.

Change-Id: I34734ebe880181480cf149d664368c8e7e469bef
Signed-off-by: Shawn O. Pearce <sop@google.com>

gerrit-war/src/main/java/com/google/gerrit/httpd/ReviewDbDataSourceProvider.java

@@ -0,0 +1,128 @@
+// Copyright (C) 2009 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.lifecycle.LifecycleListener;
+import com.google.gwtorm.jdbc.SimpleDataSource;
+import com.google.inject.Provider;
+import com.google.inject.ProvisionException;
+import com.google.inject.Singleton;
+
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.sql.SQLException;
+import java.util.Map;
+import java.util.Properties;
+
+import javax.naming.InitialContext;
+import javax.naming.NamingException;
+import javax.sql.DataSource;
+
+/** Provides access to the {@code ReviewDb} DataSource. */
+@Singleton
+final class ReviewDbDataSourceProvider implements Provider<DataSource>,
+    LifecycleListener {
+  private DataSource ds;
+
+  @Override
+  public synchronized DataSource get() {
+    if (ds == null) {
+      ds = open();
+    }
+    return ds;
+  }
+
+  @Override
+  public void start() {
+  }
+
+  @Override
+  public synchronized void stop() {
+    if (ds != null) {
+      closeDataSource(ds);
+    }
+  }
+
+  private DataSource open() {
+    final String dsName = "java:comp/env/jdbc/ReviewDb";
+    try {
+      return (DataSource) new InitialContext().lookup(dsName);
+    } catch (NamingException namingErr) {
+      final Properties p = readGerritDataSource();
+      if (p == null) {
+        throw new ProvisionException("Initialization error:\n"
+            + "  * No DataSource " + dsName + "\n"
+            + "  * No -DGerritServer=GerritServer.properties"
+            + " on Java command line", namingErr);
+      }
+
+      try {
+        return new SimpleDataSource(p);
+      } catch (SQLException se) {
+        throw new ProvisionException("Database unavailable", se);
+      }
+    }
+  }
+
+  private static Properties readGerritDataSource() throws ProvisionException {
+    final Properties srvprop = new Properties();
+    String name = System.getProperty("GerritServer");
+    if (name == null) {
+      name = "GerritServer.properties";
+    }
+    try {
+      final InputStream in = new FileInputStream(name);
+      try {
+        srvprop.load(in);
+      } finally {
+        in.close();
+      }
+    } catch (IOException e) {
+      throw new ProvisionException("Cannot read " + name, e);
+    }
+
+    final Properties dbprop = new Properties();
+    for (final Map.Entry<Object, Object> e : srvprop.entrySet()) {
+      final String key = (String) e.getKey();
+      if (key.startsWith("database.")) {
+        dbprop.put(key.substring("database.".length()), e.getValue());
+      }
+    }
+    return dbprop;
+  }
+
+  private void closeDataSource(final DataSource ds) {
+    try {
+      Class<?> type = Class.forName("org.apache.commons.dbcp.BasicDataSource");
+      if (type.isInstance(ds)) {
+        type.getMethod("close").invoke(ds);
+        return;
+      }
+    } catch (Throwable bad) {
+      // Oh well, its not a Commons DBCP pooled connection.
+    }
+
+    try {
+      Class<?> type = Class.forName("com.mchange.v2.c3p0.DataSources");
+      if (type.isInstance(ds)) {
+        type.getMethod("destroy", DataSource.class).invoke(null, ds);
+        return;
+      }
+    } catch (Throwable bad) {
+      // Oh well, its not a c3p0 pooled connection.
+    }
+  }
+}

gerrit-war/src/main/java/com/google/gerrit/httpd/WebAppInitializer.java

@@ -14,33 +14,43 @@
 
 package com.google.gerrit.httpd;
 
+import static com.google.inject.Scopes.SINGLETON;
 import static com.google.inject.Stage.PRODUCTION;
 
 import com.google.gerrit.lifecycle.LifecycleManager;
+import com.google.gerrit.lifecycle.LifecycleModule;
+import com.google.gerrit.server.config.AuthConfigModule;
 import com.google.gerrit.server.config.CanonicalWebUrlModule;
 import com.google.gerrit.server.config.DatabaseModule;
-import com.google.gerrit.server.config.GerritConfigModule;
 import com.google.gerrit.server.config.GerritGlobalModule;
+import com.google.gerrit.server.config.GerritServerConfigModule;
 import com.google.gerrit.server.config.MasterNodeStartup;
+import com.google.gerrit.server.config.SitePath;
+import com.google.gerrit.server.config.SitePathFromSystemConfigProvider;
 import com.google.gerrit.sshd.SshModule;
 import com.google.gerrit.sshd.commands.MasterCommandModule;
+import com.google.inject.AbstractModule;
 import com.google.inject.CreationException;
 import com.google.inject.Guice;
 import com.google.inject.Injector;
+import com.google.inject.Key;
 import com.google.inject.Module;
 import com.google.inject.Provider;
+import com.google.inject.name.Names;
 import com.google.inject.servlet.GuiceServletContextListener;
 import com.google.inject.spi.Message;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.io.File;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 
 import javax.servlet.ServletContextEvent;
 import javax.servlet.http.HttpServletRequest;
+import javax.sql.DataSource;
 
 /** Configures the web application environment for Gerrit Code Review. */
 public class WebAppInitializer extends GuiceServletContextListener {
@@ -57,7 +67,7 @@ public class WebAppInitializer extends GuiceServletContextListener {
   private synchronized void init() {
     if (manager == null) {
       try {
-        dbInjector = Guice.createInjector(PRODUCTION, new DatabaseModule());
+        dbInjector = createDbInjector();
       } catch (CreationException ce) {
         final Message first = ce.getErrorMessages().iterator().next();
         final StringBuilder buf = new StringBuilder();
@@ -77,7 +87,7 @@ public class WebAppInitializer extends GuiceServletContextListener {
         throw new CreationException(Collections.singleton(first));
       }
 
-      cfgInjector = dbInjector.createChildInjector(new GerritConfigModule());
+      cfgInjector = createCfgInjector();
       sysInjector = createSysInjector();
       sshInjector = createSshInjector();
       webInjector = createWebInjector();
@@ -103,6 +113,34 @@ public class WebAppInitializer extends GuiceServletContextListener {
     }
   }
 
+  private Injector createDbInjector() {
+    final List<Module> modules = new ArrayList<Module>();
+    modules.add(new LifecycleModule() {
+      @Override
+      protected void configure() {
+        bind(Key.get(DataSource.class, Names.named("ReviewDb"))).toProvider(
+            ReviewDbDataSourceProvider.class).in(SINGLETON);
+        listener().to(ReviewDbDataSourceProvider.class);
+      }
+    });
+    modules.add(new DatabaseModule());
+    return Guice.createInjector(PRODUCTION, modules);
+  }
+
+  private Injector createCfgInjector() {
+    final List<Module> modules = new ArrayList<Module>();
+    modules.add(new AbstractModule() {
+      @Override
+      protected void configure() {
+        bind(File.class).annotatedWith(SitePath.class).toProvider(
+            SitePathFromSystemConfigProvider.class).in(SINGLETON);
+      }
+    });
+    modules.add(new GerritServerConfigModule());
+    modules.add(new AuthConfigModule());
+    return dbInjector.createChildInjector(modules);
+  }
+
   private Injector createSysInjector() {
     final List<Module> modules = new ArrayList<Module>();
     modules.add(cfgInjector.getInstance(GerritGlobalModule.class));