java/com/google/gerrit/httpd/raw/StaticModule.java - gerrit - Git at Google

 // Copyright (C) 2015 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.raw;

 import static com.google.common.base.Preconditions.checkArgument;
 import static java.nio.file.Files.exists;
 import static java.nio.file.Files.isReadable;

 import com.google.common.cache.Cache;
 import com.google.common.collect.ImmutableList;
 import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.common.Nullable;
 import com.google.gerrit.extensions.api.GerritApi;
 import com.google.gerrit.httpd.XsrfCookieFilter;
 import com.google.gerrit.httpd.raw.ResourceServlet.Resource;
 import com.google.gerrit.launcher.GerritLauncher;
 import com.google.gerrit.server.cache.CacheModule;
 import com.google.gerrit.server.config.CanonicalWebUrl;
 import com.google.gerrit.server.config.GerritOptions;
 import com.google.gerrit.server.config.GerritServerConfig;
 import com.google.gerrit.server.config.SitePaths;
 import com.google.inject.Inject;
 import com.google.inject.Key;
 import com.google.inject.Provides;
 import com.google.inject.ProvisionException;
 import com.google.inject.Singleton;
 import com.google.inject.name.Named;
 import com.google.inject.name.Names;
 import com.google.inject.servlet.ServletModule;
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.nio.file.FileSystem;
 import java.nio.file.Path;
 import javax.servlet.Filter;
 import javax.servlet.FilterChain;
 import javax.servlet.FilterConfig;
 import javax.servlet.ServletException;
 import javax.servlet.ServletRequest;
 import javax.servlet.ServletResponse;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletRequestWrapper;
 import javax.servlet.http.HttpServletResponse;
 import org.eclipse.jgit.lib.Config;

 public class StaticModule extends ServletModule {
   private static final FluentLogger logger = FluentLogger.forEnclosingClass();

   public static final String CACHE = "static_content";

   /**
    * Paths at which we should serve the main PolyGerrit application {@code index.html}.
    *
    * <p>Supports {@code "/*"} as a trailing wildcard.
    */
   public static final ImmutableList<String> POLYGERRIT_INDEX_PATHS =
       ImmutableList.of(
           "/",
           "/c/*",
           "/p/*",
           "/q/*",
           "/x/*",
           "/admin/*",
           "/dashboard/*",
           "/groups/self",
           "/settings/*",
           "/Documentation/q/*");

   /**
    * Paths that should be treated as static assets when serving PolyGerrit.
    *
    * <p>Supports {@code "/*"} as a trailing wildcard.
    */
   private static final ImmutableList<String> POLYGERRIT_ASSET_PATHS =
       ImmutableList.of(
           "/behaviors/*",
           "/bower_components/*",
           "/elements/*",
           "/fonts/*",
           "/scripts/*",
           "/styles/*");

   private static final String DOC_SERVLET = "DocServlet";
   private static final String FAVICON_SERVLET = "FaviconServlet";
   private static final String POLYGERRIT_INDEX_SERVLET = "PolyGerritUiIndexServlet";
   private static final String ROBOTS_TXT_SERVLET = "RobotsTxtServlet";

   private final GerritOptions options;
   private Paths paths;

   @Inject
   public StaticModule(GerritOptions options) {
     this.options = options;
   }

   @Provides
   @Singleton
   private Paths getPaths() {
     if (paths == null) {
       paths = new Paths(options);
     }
     return paths;
   }

   @Override
   protected void configureServlets() {
     serveRegex("^/Documentation$").with(named(DOC_SERVLET));
     serveRegex("^/Documentation/$").with(named(DOC_SERVLET));
     serveRegex("^/Documentation/(.+)$").with(named(DOC_SERVLET));
     serve("/static/*").with(SiteStaticDirectoryServlet.class);
     install(
         new CacheModule() {
           @Override
           protected void configure() {
             cache(CACHE, Path.class, Resource.class)
                 .maximumWeight(1 << 20)
                 .weigher(ResourceServlet.Weigher.class);
           }
         });
     if (!options.headless()) {
       install(new CoreStaticModule());
       install(new PolyGerritModule());
     }
   }

   @Provides
   @Singleton
   @Named(DOC_SERVLET)
   HttpServlet getDocServlet(@Named(CACHE) Cache<Path, Resource> cache) {
     Paths p = getPaths();
     if (p.warFs != null) {
       return new WarDocServlet(cache, p.warFs);
     } else if (p.unpackedWar != null && !p.isDev()) {
       return new DirectoryDocServlet(cache, p.unpackedWar);
     } else {
       return new HttpServlet() {
         private static final long serialVersionUID = 1L;

         @Override
         protected void service(HttpServletRequest req, HttpServletResponse resp)
             throws IOException {
           resp.sendError(HttpServletResponse.SC_NOT_FOUND);
         }
       };
     }
   }

   private class CoreStaticModule extends ServletModule {
     @Override
     public void configureServlets() {
       serve("/robots.txt").with(named(ROBOTS_TXT_SERVLET));
       serve("/favicon.ico").with(named(FAVICON_SERVLET));
     }

     @Provides
     @Singleton
     @Named(ROBOTS_TXT_SERVLET)
     HttpServlet getRobotsTxtServlet(
         @GerritServerConfig Config cfg,
         SitePaths sitePaths,
         @Named(CACHE) Cache<Path, Resource> cache) {
       Path configPath = sitePaths.resolve(cfg.getString("httpd", null, "robotsFile"));
       if (configPath != null) {
         if (exists(configPath) && isReadable(configPath)) {
           return new SingleFileServlet(cache, configPath, true);
         }
         logger.atWarning().log("Cannot read httpd.robotsFile, using default");
       }
       Paths p = getPaths();
       if (p.warFs != null) {
         return new SingleFileServlet(cache, p.warFs.getPath("/robots.txt"), false);
       }
       return new SingleFileServlet(cache, webappSourcePath("robots.txt"), true);
     }

     @Provides
     @Singleton
     @Named(FAVICON_SERVLET)
     HttpServlet getFaviconServlet(@Named(CACHE) Cache<Path, Resource> cache) {
       Paths p = getPaths();
       if (p.warFs != null) {
         return new SingleFileServlet(cache, p.warFs.getPath("/favicon.ico"), false);
       }
       return new SingleFileServlet(cache, webappSourcePath("favicon.ico"), true);
     }

     private Path webappSourcePath(String name) {
       Paths p = getPaths();
       if (p.unpackedWar != null) {
         return p.unpackedWar.resolve(name);
       }
       return p.sourceRoot.resolve("webapp/" + name);
     }
   }

   private class PolyGerritModule extends ServletModule {
     @Override
     public void configureServlets() {
       for (String p : POLYGERRIT_INDEX_PATHS) {
         filter(p).through(XsrfCookieFilter.class);
       }
       filter("/*").through(PolyGerritFilter.class);
     }

     @Provides
     @Singleton
     @Named(POLYGERRIT_INDEX_SERVLET)
     HttpServlet getPolyGerritUiIndexServlet(
         @CanonicalWebUrl @Nullable String canonicalUrl,
         @GerritServerConfig Config cfg,
         GerritApi gerritApi) {
       String cdnPath = cfg.getString("gerrit", null, "cdnPath");
       String faviconPath = cfg.getString("gerrit", null, "faviconPath");
       return new IndexServlet(canonicalUrl, cdnPath, faviconPath, gerritApi);
     }

     @Provides
     @Singleton
     PolyGerritUiServlet getPolyGerritUiServlet(@Named(CACHE) Cache<Path, Resource> cache) {
       return new PolyGerritUiServlet(cache, polyGerritBasePath());
     }

     @Provides
     @Singleton
     BowerComponentsDevServlet getBowerComponentsServlet(@Named(CACHE) Cache<Path, Resource> cache)
         throws IOException {
       return getPaths().isDev() ? new BowerComponentsDevServlet(cache, getPaths().builder) : null;
     }

     @Provides
     @Singleton
     FontsDevServlet getFontsServlet(@Named(CACHE) Cache<Path, Resource> cache) throws IOException {
       return getPaths().isDev() ? new FontsDevServlet(cache, getPaths().builder) : null;
     }

     private Path polyGerritBasePath() {
       Paths p = getPaths();
       if (options.forcePolyGerritDev()) {
         checkArgument(
             p.sourceRoot != null, "no source root directory found for PolyGerrit developer mode");
       }

       if (p.isDev()) {
         return p.sourceRoot.resolve("polygerrit-ui").resolve("app");
       }

       return p.warFs != null
           ? p.warFs.getPath("/polygerrit_ui")
           : p.unpackedWar.resolve("polygerrit_ui");
     }
   }

   private static class Paths {
     private final FileSystem warFs;
     private final BazelBuild builder;
     private final Path sourceRoot;
     private final Path unpackedWar;
     private final boolean development;

     private Paths(GerritOptions options) {
       try {
         File launcherLoadedFrom = getLauncherLoadedFrom();
         if (launcherLoadedFrom != null && launcherLoadedFrom.getName().endsWith(".jar")) {
           // Special case: unpacked war archive deployed in container.
           // The path is something like:
           // <container>/<gerrit>/WEB-INF/lib/launcher.jar
           // Switch to exploded war case with <container>/webapp>/<gerrit>
           // root directory
           warFs = null;
           unpackedWar =
               java.nio.file.Paths.get(
                   launcherLoadedFrom.getParentFile().getParentFile().getParentFile().toURI());
           sourceRoot = null;
           development = false;
           builder = null;
           return;
         }
         warFs = getDistributionArchive(launcherLoadedFrom);
         if (warFs == null) {
           unpackedWar = makeWarTempDir();
           development = true;
         } else if (options.forcePolyGerritDev()) {
           unpackedWar = null;
           development = true;
         } else {
           unpackedWar = null;
           development = false;
           sourceRoot = null;
           builder = null;
           return;
         }
       } catch (IOException e) {
         throw new ProvisionException("Error initializing static content paths", e);
       }

       sourceRoot = getSourceRootOrNull();
       builder = new BazelBuild(sourceRoot);
     }

     private static Path getSourceRootOrNull() {
       try {
         return GerritLauncher.resolveInSourceRoot(".");
       } catch (FileNotFoundException e) {
         return null;
       }
     }

     private FileSystem getDistributionArchive(File war) throws IOException {
       if (war == null) {
         return null;
       }
       return GerritLauncher.getZipFileSystem(war.toPath());
     }

     private File getLauncherLoadedFrom() {
       File war;
       try {
         war = GerritLauncher.getDistributionArchive();
       } catch (IOException e) {
         if ((e instanceof FileNotFoundException)
             && GerritLauncher.NOT_ARCHIVED.equals(e.getMessage())) {
           return null;
         }
         throw new ProvisionException("Error reading gerrit.war", e);
       }
       return war;
     }

     private boolean isDev() {
       return development;
     }

     private Path makeWarTempDir() {
       // Obtain our local temporary directory, but it comes back as a file
       // so we have to switch it to be a directory post creation.
       //
       try {
         File dstwar = GerritLauncher.createTempFile("gerrit_", "war");
         if (!dstwar.delete() || !dstwar.mkdir()) {
           throw new IOException("Cannot mkdir " + dstwar.getAbsolutePath());
         }

         // Jetty normally refuses to serve out of a symlinked directory, as
         // a security feature. Try to resolve out any symlinks in the path.
         //
         try {
           return dstwar.getCanonicalFile().toPath();
         } catch (IOException e) {
           return dstwar.getAbsoluteFile().toPath();
         }
       } catch (IOException e) {
         throw new ProvisionException("Cannot create war tempdir", e);
       }
     }
   }

   private static Key<HttpServlet> named(String name) {
     return Key.get(HttpServlet.class, Names.named(name));
   }

   @Singleton
   private static class PolyGerritFilter implements Filter {
     private final Paths paths;
     private final HttpServlet polyGerritIndex;
     private final PolyGerritUiServlet polygerritUI;
     private final BowerComponentsDevServlet bowerComponentServlet;
     private final FontsDevServlet fontServlet;

     @Inject
     PolyGerritFilter(
         Paths paths,
         @Named(POLYGERRIT_INDEX_SERVLET) HttpServlet polyGerritIndex,
         PolyGerritUiServlet polygerritUI,
         @Nullable BowerComponentsDevServlet bowerComponentServlet,
         @Nullable FontsDevServlet fontServlet) {
       this.paths = paths;
       this.polyGerritIndex = polyGerritIndex;
       this.polygerritUI = polygerritUI;
       this.bowerComponentServlet = bowerComponentServlet;
       this.fontServlet = fontServlet;
     }

     @Override
     public void init(FilterConfig filterConfig) throws ServletException {}

     @Override
     public void destroy() {}

     @Override
     public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
         throws IOException, ServletException {
       HttpServletRequest req = (HttpServletRequest) request;
       HttpServletResponse res = (HttpServletResponse) response;

       GuiceFilterRequestWrapper reqWrapper = new GuiceFilterRequestWrapper(req);
       String path = pathInfo(req);

       // Special case assets during development that are built by Bazel and not
       // served out of the source tree.
       //
       // In the war case, these are either inlined, or live under
       // /polygerrit_ui in the war file, so we can just treat them as normal
       // assets.
       if (paths.isDev()) {
         if (path.startsWith("/bower_components/")) {
           bowerComponentServlet.service(reqWrapper, res);
           return;
         } else if (path.startsWith("/fonts/")) {
           fontServlet.service(reqWrapper, res);
           return;
         }
       }

       if (isPolyGerritIndex(path)) {
         polyGerritIndex.service(reqWrapper, res);
         return;
       }
       if (isPolyGerritAsset(path)) {
         polygerritUI.service(reqWrapper, res);
         return;
       }

       chain.doFilter(req, res);
     }

     private static String pathInfo(HttpServletRequest req) {
       String uri = req.getRequestURI();
       String ctx = req.getContextPath();
       return uri.startsWith(ctx) ? uri.substring(ctx.length()) : uri;
     }

     private static boolean isPolyGerritAsset(String path) {
       return matchPath(POLYGERRIT_ASSET_PATHS, path);
     }

     private static boolean isPolyGerritIndex(String path) {
       return matchPath(POLYGERRIT_INDEX_PATHS, path);
     }

     private static boolean matchPath(Iterable<String> paths, String path) {
       for (String p : paths) {
         if (p.endsWith("/*")) {
           if (path.regionMatches(0, p, 0, p.length() - 1)) {
             return true;
           }
         } else if (p.equals(path)) {
           return true;
         }
       }
       return false;
     }
   }

   private static class GuiceFilterRequestWrapper extends HttpServletRequestWrapper {
     GuiceFilterRequestWrapper(HttpServletRequest req) {
       super(req);
     }

     @Override
     public String getPathInfo() {
       String uri = getRequestURI();
       String ctx = getContextPath();
       // This is a workaround for long standing guice filter bug:
       // https://github.com/google/guice/issues/807
       String res = uri.startsWith(ctx) ? uri.substring(ctx.length()) : uri;

       // Match the logic in the ResourceServlet, that re-add "/"
       // for null path info
       if ("/".equals(res)) {
         return null;
       }
       return res;
     }
   }
 }
	// Copyright (C) 2015 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.raw;

	import static com.google.common.base.Preconditions.checkArgument;
	import static java.nio.file.Files.exists;
	import static java.nio.file.Files.isReadable;

	import com.google.common.cache.Cache;
	import com.google.common.collect.ImmutableList;
	import com.google.common.flogger.FluentLogger;
	import com.google.gerrit.common.Nullable;
	import com.google.gerrit.extensions.api.GerritApi;
	import com.google.gerrit.httpd.XsrfCookieFilter;
	import com.google.gerrit.httpd.raw.ResourceServlet.Resource;
	import com.google.gerrit.launcher.GerritLauncher;
	import com.google.gerrit.server.cache.CacheModule;
	import com.google.gerrit.server.config.CanonicalWebUrl;
	import com.google.gerrit.server.config.GerritOptions;
	import com.google.gerrit.server.config.GerritServerConfig;
	import com.google.gerrit.server.config.SitePaths;
	import com.google.inject.Inject;
	import com.google.inject.Key;
	import com.google.inject.Provides;
	import com.google.inject.ProvisionException;
	import com.google.inject.Singleton;
	import com.google.inject.name.Named;
	import com.google.inject.name.Names;
	import com.google.inject.servlet.ServletModule;
	import java.io.File;
	import java.io.FileNotFoundException;
	import java.io.IOException;
	import java.nio.file.FileSystem;
	import java.nio.file.Path;
	import javax.servlet.Filter;
	import javax.servlet.FilterChain;
	import javax.servlet.FilterConfig;
	import javax.servlet.ServletException;
	import javax.servlet.ServletRequest;
	import javax.servlet.ServletResponse;
	import javax.servlet.http.HttpServlet;
	import javax.servlet.http.HttpServletRequest;
	import javax.servlet.http.HttpServletRequestWrapper;
	import javax.servlet.http.HttpServletResponse;
	import org.eclipse.jgit.lib.Config;

	public class StaticModule extends ServletModule {
	private static final FluentLogger logger = FluentLogger.forEnclosingClass();

	public static final String CACHE = "static_content";

	/**
	* Paths at which we should serve the main PolyGerrit application {@code index.html}.
	*
	* <p>Supports {@code "/*"} as a trailing wildcard.
	*/
	public static final ImmutableList<String> POLYGERRIT_INDEX_PATHS =
	ImmutableList.of(
	"/",
	"/c/*",
	"/p/*",
	"/q/*",
	"/x/*",
	"/admin/*",
	"/dashboard/*",
	"/groups/self",
	"/settings/*",
	"/Documentation/q/*");

	/**
	* Paths that should be treated as static assets when serving PolyGerrit.
	*
	* <p>Supports {@code "/*"} as a trailing wildcard.
	*/
	private static final ImmutableList<String> POLYGERRIT_ASSET_PATHS =
	ImmutableList.of(
	"/behaviors/*",
	"/bower_components/*",
	"/elements/*",
	"/fonts/*",
	"/scripts/*",
	"/styles/*");

	private static final String DOC_SERVLET = "DocServlet";
	private static final String FAVICON_SERVLET = "FaviconServlet";
	private static final String POLYGERRIT_INDEX_SERVLET = "PolyGerritUiIndexServlet";
	private static final String ROBOTS_TXT_SERVLET = "RobotsTxtServlet";

	private final GerritOptions options;
	private Paths paths;

	@Inject
	public StaticModule(GerritOptions options) {
	this.options = options;
	}

	@Provides
	@Singleton
	private Paths getPaths() {
	if (paths == null) {
	paths = new Paths(options);
	}
	return paths;
	}

	@Override
	protected void configureServlets() {
	serveRegex("^/Documentation$").with(named(DOC_SERVLET));
	serveRegex("^/Documentation/$").with(named(DOC_SERVLET));
	serveRegex("^/Documentation/(.+)$").with(named(DOC_SERVLET));
	serve("/static/*").with(SiteStaticDirectoryServlet.class);
	install(
	new CacheModule() {
	@Override
	protected void configure() {
	cache(CACHE, Path.class, Resource.class)
	.maximumWeight(1 << 20)
	.weigher(ResourceServlet.Weigher.class);
	}
	});
	if (!options.headless()) {
	install(new CoreStaticModule());
	install(new PolyGerritModule());
	}
	}

	@Provides
	@Singleton
	@Named(DOC_SERVLET)
	HttpServlet getDocServlet(@Named(CACHE) Cache<Path, Resource> cache) {
	Paths p = getPaths();
	if (p.warFs != null) {
	return new WarDocServlet(cache, p.warFs);
	} else if (p.unpackedWar != null && !p.isDev()) {
	return new DirectoryDocServlet(cache, p.unpackedWar);
	} else {
	return new HttpServlet() {
	private static final long serialVersionUID = 1L;

	@Override
	protected void service(HttpServletRequest req, HttpServletResponse resp)
	throws IOException {
	resp.sendError(HttpServletResponse.SC_NOT_FOUND);
	}
	};
	}
	}

	private class CoreStaticModule extends ServletModule {
	@Override
	public void configureServlets() {
	serve("/robots.txt").with(named(ROBOTS_TXT_SERVLET));
	serve("/favicon.ico").with(named(FAVICON_SERVLET));
	}

	@Provides
	@Singleton
	@Named(ROBOTS_TXT_SERVLET)
	HttpServlet getRobotsTxtServlet(
	@GerritServerConfig Config cfg,
	SitePaths sitePaths,
	@Named(CACHE) Cache<Path, Resource> cache) {
	Path configPath = sitePaths.resolve(cfg.getString("httpd", null, "robotsFile"));
	if (configPath != null) {
	if (exists(configPath) && isReadable(configPath)) {
	return new SingleFileServlet(cache, configPath, true);
	}
	logger.atWarning().log("Cannot read httpd.robotsFile, using default");
	}
	Paths p = getPaths();
	if (p.warFs != null) {
	return new SingleFileServlet(cache, p.warFs.getPath("/robots.txt"), false);
	}
	return new SingleFileServlet(cache, webappSourcePath("robots.txt"), true);
	}

	@Provides
	@Singleton
	@Named(FAVICON_SERVLET)
	HttpServlet getFaviconServlet(@Named(CACHE) Cache<Path, Resource> cache) {
	Paths p = getPaths();
	if (p.warFs != null) {
	return new SingleFileServlet(cache, p.warFs.getPath("/favicon.ico"), false);
	}
	return new SingleFileServlet(cache, webappSourcePath("favicon.ico"), true);
	}

	private Path webappSourcePath(String name) {
	Paths p = getPaths();
	if (p.unpackedWar != null) {
	return p.unpackedWar.resolve(name);
	}
	return p.sourceRoot.resolve("webapp/" + name);
	}
	}

	private class PolyGerritModule extends ServletModule {
	@Override
	public void configureServlets() {
	for (String p : POLYGERRIT_INDEX_PATHS) {
	filter(p).through(XsrfCookieFilter.class);
	}
	filter("/*").through(PolyGerritFilter.class);
	}

	@Provides
	@Singleton
	@Named(POLYGERRIT_INDEX_SERVLET)
	HttpServlet getPolyGerritUiIndexServlet(
	@CanonicalWebUrl @Nullable String canonicalUrl,
	@GerritServerConfig Config cfg,
	GerritApi gerritApi) {
	String cdnPath = cfg.getString("gerrit", null, "cdnPath");
	String faviconPath = cfg.getString("gerrit", null, "faviconPath");
	return new IndexServlet(canonicalUrl, cdnPath, faviconPath, gerritApi);
	}

	@Provides
	@Singleton
	PolyGerritUiServlet getPolyGerritUiServlet(@Named(CACHE) Cache<Path, Resource> cache) {
	return new PolyGerritUiServlet(cache, polyGerritBasePath());
	}

	@Provides
	@Singleton
	BowerComponentsDevServlet getBowerComponentsServlet(@Named(CACHE) Cache<Path, Resource> cache)
	throws IOException {
	return getPaths().isDev() ? new BowerComponentsDevServlet(cache, getPaths().builder) : null;
	}

	@Provides
	@Singleton
	FontsDevServlet getFontsServlet(@Named(CACHE) Cache<Path, Resource> cache) throws IOException {
	return getPaths().isDev() ? new FontsDevServlet(cache, getPaths().builder) : null;
	}

	private Path polyGerritBasePath() {
	Paths p = getPaths();
	if (options.forcePolyGerritDev()) {
	checkArgument(
	p.sourceRoot != null, "no source root directory found for PolyGerrit developer mode");
	}

	if (p.isDev()) {
	return p.sourceRoot.resolve("polygerrit-ui").resolve("app");
	}

	return p.warFs != null
	? p.warFs.getPath("/polygerrit_ui")
	: p.unpackedWar.resolve("polygerrit_ui");
	}
	}

	private static class Paths {
	private final FileSystem warFs;
	private final BazelBuild builder;
	private final Path sourceRoot;
	private final Path unpackedWar;
	private final boolean development;

	private Paths(GerritOptions options) {
	try {
	File launcherLoadedFrom = getLauncherLoadedFrom();
	if (launcherLoadedFrom != null && launcherLoadedFrom.getName().endsWith(".jar")) {
	// Special case: unpacked war archive deployed in container.
	// The path is something like:
	// <container>/<gerrit>/WEB-INF/lib/launcher.jar
	// Switch to exploded war case with <container>/webapp>/<gerrit>
	// root directory
	warFs = null;
	unpackedWar =
	java.nio.file.Paths.get(
	launcherLoadedFrom.getParentFile().getParentFile().getParentFile().toURI());
	sourceRoot = null;
	development = false;
	builder = null;
	return;
	}
	warFs = getDistributionArchive(launcherLoadedFrom);
	if (warFs == null) {
	unpackedWar = makeWarTempDir();
	development = true;
	} else if (options.forcePolyGerritDev()) {
	unpackedWar = null;
	development = true;
	} else {
	unpackedWar = null;
	development = false;
	sourceRoot = null;
	builder = null;
	return;
	}
	} catch (IOException e) {
	throw new ProvisionException("Error initializing static content paths", e);
	}

	sourceRoot = getSourceRootOrNull();
	builder = new BazelBuild(sourceRoot);
	}

	private static Path getSourceRootOrNull() {
	try {
	return GerritLauncher.resolveInSourceRoot(".");
	} catch (FileNotFoundException e) {
	return null;
	}
	}

	private FileSystem getDistributionArchive(File war) throws IOException {
	if (war == null) {
	return null;
	}
	return GerritLauncher.getZipFileSystem(war.toPath());
	}

	private File getLauncherLoadedFrom() {
	File war;
	try {
	war = GerritLauncher.getDistributionArchive();
	} catch (IOException e) {
	if ((e instanceof FileNotFoundException)
	&& GerritLauncher.NOT_ARCHIVED.equals(e.getMessage())) {
	return null;
	}
	throw new ProvisionException("Error reading gerrit.war", e);
	}
	return war;
	}

	private boolean isDev() {
	return development;
	}

	private Path makeWarTempDir() {
	// Obtain our local temporary directory, but it comes back as a file
	// so we have to switch it to be a directory post creation.
	//
	try {
	File dstwar = GerritLauncher.createTempFile("gerrit_", "war");
	if (!dstwar.delete() \|\| !dstwar.mkdir()) {
	throw new IOException("Cannot mkdir " + dstwar.getAbsolutePath());
	}

	// Jetty normally refuses to serve out of a symlinked directory, as
	// a security feature. Try to resolve out any symlinks in the path.
	//
	try {
	return dstwar.getCanonicalFile().toPath();
	} catch (IOException e) {
	return dstwar.getAbsoluteFile().toPath();
	}
	} catch (IOException e) {
	throw new ProvisionException("Cannot create war tempdir", e);
	}
	}
	}

	private static Key<HttpServlet> named(String name) {
	return Key.get(HttpServlet.class, Names.named(name));
	}

	@Singleton
	private static class PolyGerritFilter implements Filter {
	private final Paths paths;
	private final HttpServlet polyGerritIndex;
	private final PolyGerritUiServlet polygerritUI;
	private final BowerComponentsDevServlet bowerComponentServlet;
	private final FontsDevServlet fontServlet;

	@Inject
	PolyGerritFilter(
	Paths paths,
	@Named(POLYGERRIT_INDEX_SERVLET) HttpServlet polyGerritIndex,
	PolyGerritUiServlet polygerritUI,
	@Nullable BowerComponentsDevServlet bowerComponentServlet,
	@Nullable FontsDevServlet fontServlet) {
	this.paths = paths;
	this.polyGerritIndex = polyGerritIndex;
	this.polygerritUI = polygerritUI;
	this.bowerComponentServlet = bowerComponentServlet;
	this.fontServlet = fontServlet;
	}

	@Override
	public void init(FilterConfig filterConfig) throws ServletException {}

	@Override
	public void destroy() {}

	@Override
	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
	throws IOException, ServletException {
	HttpServletRequest req = (HttpServletRequest) request;
	HttpServletResponse res = (HttpServletResponse) response;

	GuiceFilterRequestWrapper reqWrapper = new GuiceFilterRequestWrapper(req);
	String path = pathInfo(req);

	// Special case assets during development that are built by Bazel and not
	// served out of the source tree.
	//
	// In the war case, these are either inlined, or live under
	// /polygerrit_ui in the war file, so we can just treat them as normal
	// assets.
	if (paths.isDev()) {
	if (path.startsWith("/bower_components/")) {
	bowerComponentServlet.service(reqWrapper, res);
	return;
	} else if (path.startsWith("/fonts/")) {
	fontServlet.service(reqWrapper, res);
	return;
	}
	}

	if (isPolyGerritIndex(path)) {
	polyGerritIndex.service(reqWrapper, res);
	return;
	}
	if (isPolyGerritAsset(path)) {
	polygerritUI.service(reqWrapper, res);
	return;
	}

	chain.doFilter(req, res);
	}

	private static String pathInfo(HttpServletRequest req) {
	String uri = req.getRequestURI();
	String ctx = req.getContextPath();
	return uri.startsWith(ctx) ? uri.substring(ctx.length()) : uri;
	}

	private static boolean isPolyGerritAsset(String path) {
	return matchPath(POLYGERRIT_ASSET_PATHS, path);
	}

	private static boolean isPolyGerritIndex(String path) {
	return matchPath(POLYGERRIT_INDEX_PATHS, path);
	}

	private static boolean matchPath(Iterable<String> paths, String path) {
	for (String p : paths) {
	if (p.endsWith("/*")) {
	if (path.regionMatches(0, p, 0, p.length() - 1)) {
	return true;
	}
	} else if (p.equals(path)) {
	return true;
	}
	}
	return false;
	}
	}

	private static class GuiceFilterRequestWrapper extends HttpServletRequestWrapper {
	GuiceFilterRequestWrapper(HttpServletRequest req) {
	super(req);
	}

	@Override
	public String getPathInfo() {
	String uri = getRequestURI();
	String ctx = getContextPath();
	// This is a workaround for long standing guice filter bug:
	// https://github.com/google/guice/issues/807
	String res = uri.startsWith(ctx) ? uri.substring(ctx.length()) : uri;

	// Match the logic in the ResourceServlet, that re-add "/"
	// for null path info
	if ("/".equals(res)) {
	return null;
	}
	return res;
	}
	}
	}