Serve PolyGerrit index.html from a Soy template

Rather than serving a static file, serve the PolyGerrit index HTML
document from a Soy template. In this way, the path to load PG
dependencies can be safely parameterized in two ways:

* If Gerrit is not running on the root of the domain (e.g. listening on
  https://example.com/my-gerrit/) the path component of the Canonical
  Web URL is used to load PG dependencies.

  Instead of /elements/gr-app.js off the root of the domain it uses
  /my-gerrit/elements/gr-app.js

* If the PolyGerrit static resources are to be served from a CDN rather
  than the Gerrit WAR, the `cdnPath` config in the [gerrit] section can
  be used.

  For example, if the server config says ...

  [gerrit]
    cdnPath = http://my-cdn.com/pg/version/123

  ... then it uses the following style of path for PG dependencies.

  http://my-cdn.com/pg/version/123/my-gerrit/elements/gr-app.js

  If a CDN-path is configured, it supersedes subdirectories appearing
  in the Canonical-Web-URL for this purpose.

Feature: Issue 5845
Change-Id: I2b2d704fe33c90ea2f2a2183fc79897642a48175
(cherry picked from commit 414659c792)

Documentation/config-gerrit.txt

@@ -2059,6 +2059,10 @@ Setting this option to true will prevent this behavior.
 +
 By default false.
 
+[[gerrit.cdnPath]]gerrit.cdnPath::
++
+Path prefix for PolyGerrit's static resources if using a CDN.
+
 [[gitweb]]
 === Section gitweb
 

gerrit-httpd/BUILD

@@ -37,6 +37,7 @@ java_library(
         "//lib:jsch",
         "//lib:mime-util",
         "//lib:servlet-api-3_1",
+        "//lib:soy",
         "//lib/auto:auto-value",
         "//lib/commons:codec",
         "//lib/guice",
@@ -54,6 +55,7 @@ junit_tests(
     srcs = glob(["src/test/java/**/*.java"]),
     deps = [
         ":httpd",
+        "//gerrit-common:annotations",
         "//gerrit-common:server",
         "//gerrit-extension-api:api",
         "//gerrit-reviewdb:server",
@@ -66,6 +68,7 @@ junit_tests(
         "//lib:jimfs",
         "//lib:junit",
         "//lib:servlet-api-3_1-without-neverlink",
+        "//lib:soy",
         "//lib:truth",
         "//lib/easymock",
         "//lib/guice",

gerrit-httpd/src/main/java/com/google/gerrit/httpd/raw/IndexServlet.java

@@ -0,0 +1,85 @@
+// Copyright (C) 2017 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 java.nio.charset.StandardCharsets.UTF_8;
+import static javax.servlet.http.HttpServletResponse.SC_OK;
+
+import com.google.common.io.Resources;
+import com.google.gerrit.common.Nullable;
+import com.google.template.soy.SoyFileSet;
+import com.google.template.soy.data.SanitizedContent;
+import com.google.template.soy.data.SoyMapData;
+import com.google.template.soy.tofu.SoyTofu;
+import com.google.template.soy.data.UnsafeSanitizedContentOrdainer;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.net.URI;
+import java.net.URISyntaxException;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+public class IndexServlet extends HttpServlet {
+  private final byte[] indexSource;
+
+  IndexServlet(String canonicalURL, @Nullable String cdnPath) throws URISyntaxException {
+    String resourcePath = "com/google/gerrit/httpd/raw/index.html.soy";
+    SoyFileSet.Builder builder = SoyFileSet.builder();
+    builder.add(Resources.getResource(resourcePath));
+    SoyTofu.Renderer renderer = builder.build().compileToTofu()
+        .newRenderer("com.google.gerrit.httpd.raw.Index")
+        .setContentKind(SanitizedContent.ContentKind.HTML)
+        .setData(getTemplateData(canonicalURL, cdnPath));
+    indexSource = renderer.render().getBytes();
+  }
+
+  @Override
+  protected void doGet(HttpServletRequest req, HttpServletResponse rsp) throws IOException {
+    rsp.setCharacterEncoding(UTF_8.name());
+    rsp.setContentType("text/html");
+    rsp.setStatus(SC_OK);
+    try (OutputStream w = rsp.getOutputStream()) {
+      w.write(indexSource);
+    }
+  }
+
+  static String computeCanonicalPath(String canonicalURL) throws URISyntaxException {
+    // If we serving from a sub-directory rather than root, determine the path
+    // from the cannonical web URL.
+    URI uri = new URI(canonicalURL);
+    return uri.getPath().replaceAll("/$", "");
+  }
+
+  static SoyMapData getTemplateData(String canonicalURL, String cdnPath) throws URISyntaxException {
+    String canonicalPath = computeCanonicalPath(canonicalURL);
+
+    String staticPath = "";
+    if (cdnPath != null) {
+      staticPath = cdnPath;
+    } else if (canonicalPath != null) {
+      staticPath = canonicalPath;
+    }
+
+    // The resource path must be typed as safe for use in a script src.
+    // TODO(wyatta): Upgrade this to use an appropriate safe URL type.
+    SanitizedContent sanitizedStaticPath = UnsafeSanitizedContentOrdainer.ordainAsSafe(staticPath,
+        SanitizedContent.ContentKind.TRUSTED_RESOURCE_URI);
+
+    return new SoyMapData(
+        "canonicalPath", canonicalPath,
+        "staticResourcePath", sanitizedStaticPath);
+  }
+}

gerrit-httpd/src/main/java/com/google/gerrit/httpd/raw/StaticModule.java

@@ -27,11 +27,13 @@ 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.Provider;
 import com.google.inject.Provides;
 import com.google.inject.ProvisionException;
 import com.google.inject.Singleton;
@@ -41,6 +43,7 @@ import com.google.inject.servlet.ServletModule;
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.net.URISyntaxException;
 import java.nio.file.FileSystem;
 import java.nio.file.Path;
 import javax.servlet.Filter;
@@ -249,9 +252,10 @@ public class StaticModule extends ServletModule {
     @Provides
     @Singleton
     @Named(POLYGERRIT_INDEX_SERVLET)
-    HttpServlet getPolyGerritUiIndexServlet(@Named(CACHE) Cache<Path, Resource> cache) {
+    HttpServlet getPolyGerritUiIndexServlet(@CanonicalWebUrl @Nullable String canonicalUrl,
-      return new SingleFileServlet(
+        @GerritServerConfig Config cfg) throws URISyntaxException {
-          cache, polyGerritBasePath().resolve("index.html"), getPaths().isDev(), false);
+      String cdnPath = cfg.getString("gerrit", null, "cdnPath");
+      return new IndexServlet(canonicalUrl, cdnPath);
     }
 
     @Provides

gerrit-httpd/src/main/resources/com/google/gerrit/httpd/raw/index.html.soy

@@ -0,0 +1,42 @@
+/**
+ * Copyright (C) 2017 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.
+ */
+
+{namespace com.google.gerrit.httpd.raw}
+
+/**
+ * @param canonicalPath
+ * @param staticResourcePath
+ */
+{template .Index autoescape="strict" kind="html"}
+  <!DOCTYPE html>{\n}
+  <html lang="en">{\n}
+  <meta charset="utf-8">{\n}
+  <meta name="description" content="Gerrit Code Review">{\n}
+  <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=0">{\n}
+
+  // SourceCodePro fonts are used in styles/fonts.css
+  // @see https://github.com/w3c/preload/issues/32 regarding crossorigin
+  <link rel="preload" href="{$staticResourcePath}/fonts/SourceCodePro-Regular.woff2" as="font" type="font/woff2" crossorigin>{\n}
+  <link rel="preload" href="{$staticResourcePath}/fonts/SourceCodePro-Regular.woff" as="font" type="font/woff" crossorigin>{\n}
+  <link rel="stylesheet" href="{$staticResourcePath}/styles/fonts.css">{\n}
+  <link rel="stylesheet" href="{$staticResourcePath}/styles/main.css">{\n}
+  <script src="{$staticResourcePath}/bower_components/webcomponentsjs/webcomponents-lite.js"></script>{\n}
+  <link rel="preload" href="{$staticResourcePath}/elements/gr-app.js" as="script" crossorigin="anonymous">{\n}
+  <link rel="import" href="{$staticResourcePath}/elements/gr-app.html">{\n}
+
+  <body unresolved>{\n}
+  <gr-app id="app" canonical-path="{$canonicalPath}"></gr-app>{\n}
+{/template}

gerrit-httpd/src/test/java/com/google/gerrit/httpd/raw/IndexServletTest.java

@@ -0,0 +1,56 @@
+// Copyright (C) 2017 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 com.google.gerrit.common.Nullable;
+import com.google.template.soy.data.SoyMapData;
+import java.net.URISyntaxException;
+import org.junit.Test;
+
+import static com.google.common.truth.Truth.assertThat;
+
+public class IndexServletTest {
+  @Test
+  public void noPathAndNoCDN() throws URISyntaxException {
+    SoyMapData data = IndexServlet.getTemplateData("http://example.com/", null);
+    assertThat(data.getSingle("canonicalPath").stringValue()).isEqualTo("");
+    assertThat(data.getSingle("staticResourcePath").stringValue()).isEqualTo("");
+  }
+
+  @Test
+  public void pathAndNoCDN() throws URISyntaxException {
+    SoyMapData data = IndexServlet.getTemplateData("http://example.com/gerrit/", null);
+    assertThat(data.getSingle("canonicalPath").stringValue()).isEqualTo("/gerrit");
+    assertThat(data.getSingle("staticResourcePath").stringValue()).isEqualTo("/gerrit");
+  }
+
+  @Test
+  public void noPathAndCDN() throws URISyntaxException {
+    SoyMapData data = IndexServlet.getTemplateData("http://example.com/",
+        "http://my-cdn.com/foo/bar/");
+    assertThat(data.getSingle("canonicalPath").stringValue()).isEqualTo("");
+    assertThat(data.getSingle("staticResourcePath").stringValue())
+        .isEqualTo("http://my-cdn.com/foo/bar/");
+  }
+
+  @Test
+  public void pathAndCDN() throws URISyntaxException {
+    SoyMapData data = IndexServlet.getTemplateData("http://example.com/gerrit",
+        "http://my-cdn.com/foo/bar/");
+    assertThat(data.getSingle("canonicalPath").stringValue()).isEqualTo("/gerrit");
+    assertThat(data.getSingle("staticResourcePath").stringValue())
+        .isEqualTo("http://my-cdn.com/foo/bar/");
+  }
+}

polygerrit-ui/app/elements/gr-app.js

@@ -37,6 +37,12 @@
         value: function() { return document.body; },
       },
 
+      /**
+       * The path component of the canonicalWebURL. If Gerrit is running from
+       * the root of the domain, this should be empty.
+       */
+      canonicalPath: String,
+
       _account: {
         type: Object,
         observer: '_accountChanged',
@@ -73,8 +79,11 @@
       '?': '_showKeyboardShortcuts',
     },
 
-    attached: function() {
+    ready: function() {
+      Gerrit.CANONICAL_PATH = this.canonicalPath;
+
       this.$.router.start();
+
       this.$.restAPI.getAccount().then(function(account) {
         this._account = account;
       }.bind(this));
@@ -84,9 +93,7 @@
       this.$.restAPI.getVersion().then(function(version) {
         this._version = version;
       }.bind(this));
-    },
 
-    ready: function() {
       this.$.reporting.appStarted();
       this._viewState = {
         changeView: {
@@ -108,6 +115,8 @@
     },
 
     _accountChanged: function(account) {
+      if (!account) { return; }
+
       // Preferences are cached when a user is logged in; warm them.
       this.$.restAPI.getPreferences();
       this.$.restAPI.getDiffPreferences();

polygerrit-ui/app/elements/gr-app_test.html

@@ -25,7 +25,7 @@ limitations under the License.
 
 <test-fixture id="basic">
   <template>
-    <gr-app id="app"></gr-app>
+    <gr-app id="app" canonical-path="/abc/def/ghi"></gr-app>
   </template>
 </test-fixture>
 
@@ -39,6 +39,9 @@ limitations under the License.
       stub('gr-reporting', {
         appStarted: sandbox.stub(),
       });
+      stub('gr-account-dropdown', {
+        _getTopContent: sinon.stub(),
+      });
       stub('gr-rest-api-interface', {
         getAccount: function() { return Promise.resolve(null); },
         getConfig: function() {
@@ -94,5 +97,9 @@ limitations under the License.
       element._loadPlugins([]);
       assert.isTrue(Gerrit._setPluginsCount.calledWithExactly(0));
     });
+
+    test('canonical-path', function() {
+      assert.equal(Gerrit.CANONICAL_PATH, '/abc/def/ghi');
+    });
   });
 </script>