1 files changed, 76 insertions, 0 deletions
diff --git a/java/com/google/gerrit/httpd/HttpCanonicalWebUrlProvider.java b/java/com/google/gerrit/httpd/HttpCanonicalWebUrlProvider.java
new file mode 100644
index 0000000000..6943faa87f
--- /dev/null
+++ b/java/com/google/gerrit/httpd/HttpCanonicalWebUrlProvider.java
@@ -0,0 +1,76 @@
+// 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.server.config.CanonicalWebUrlProvider;
+import com.google.gerrit.server.config.GerritServerConfig;
+import com.google.inject.Inject;
+import com.google.inject.OutOfScopeException;
+import com.google.inject.Provider;
+import com.google.inject.ProvisionException;
+import java.util.Optional;
+import javax.servlet.http.HttpServletRequest;
+import org.eclipse.jgit.lib.Config;
+import org.eclipse.jgit.util.SystemReader;
+
+/** Sets {@code CanonicalWebUrl} to current HTTP request if not configured. */
+public class HttpCanonicalWebUrlProvider extends CanonicalWebUrlProvider {
+  private Provider<HttpServletRequest> requestProvider;
+
+  @Inject
+  HttpCanonicalWebUrlProvider(@GerritServerConfig Config config) {
+    super(config);
+  }
+
+  @Inject(optional = true)
+  public void setHttpServletRequest(Provider<HttpServletRequest> hsr) {
+    requestProvider = hsr;
+  }
+
+  @Override
+  public String get() {
+    String canonicalUrl = super.get();
+    if (canonicalUrl != null) {
+      return canonicalUrl;
+    }
+
+    return guessUrlFromHttpRequest()
+        .orElseGet(() -> "http://" + SystemReader.getInstance().getHostname() + '/');
+  }
+
+  private Optional<String> guessUrlFromHttpRequest() {
+    if (requestProvider == null) {
+      // We have no way of guessing our HTTP url.
+      return Optional.empty();
+    }
+
+    // No canonical URL configured? Maybe we can get a reasonable
+    // guess from the incoming HTTP request, if we are currently
+    // inside of an HTTP request scope.
+    //
+    final HttpServletRequest req;
+    try {
+      req = requestProvider.get();
+    } catch (ProvisionException noWeb) {
+      if (noWeb.getCause() instanceof OutOfScopeException) {
+        // We can't obtain the request as we are not inside of
+        // an HTTP request scope. Callers must handle null.
+        return Optional.empty();
+      }
+      throw noWeb;
+    }
+    return Optional.of(CanonicalWebUrl.computeFromRequest(req));
+  }
+}