1 files changed, 77 insertions, 0 deletions
diff --git a/java/com/google/gerrit/server/config/GerritServerIdProvider.java b/java/com/google/gerrit/server/config/GerritServerIdProvider.java
new file mode 100644
index 0000000000..c609cc4dca
--- /dev/null
+++ b/java/com/google/gerrit/server/config/GerritServerIdProvider.java
@@ -0,0 +1,77 @@
+// Copyright (C) 2016 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.server.config;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+
+import com.google.common.base.Strings;
+import com.google.inject.Inject;
+import com.google.inject.Provider;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.util.UUID;
+import org.eclipse.jgit.errors.ConfigInvalidException;
+import org.eclipse.jgit.lib.Config;
+import org.eclipse.jgit.storage.file.FileBasedConfig;
+import org.eclipse.jgit.util.FS;
+
+public class GerritServerIdProvider implements Provider<String> {
+  public static final String SECTION = "gerrit";
+  public static final String KEY = "serverId";
+
+  public static String generate() {
+    return UUID.randomUUID().toString();
+  }
+
+  private final String id;
+
+  @Inject
+  public GerritServerIdProvider(@GerritServerConfig Config cfg, SitePaths sitePaths)
+      throws IOException, ConfigInvalidException {
+    String origId = cfg.getString(SECTION, null, KEY);
+    if (!Strings.isNullOrEmpty(origId)) {
+      id = origId;
+      return;
+    }
+
+    // We're not generally supposed to do work in provider constructors, but this is a bit of a
+    // special case because we really need to have the ID available by the time the dbInjector
+    // is created. This even applies during MigrateToNoteDb, which otherwise would have been a
+    // reasonable place to do the ID generation. Fortunately, it's not much work, and it happens
+    // once.
+    id = generate();
+    Config newCfg = readGerritConfig(sitePaths);
+    newCfg.setString(SECTION, null, KEY, id);
+    Files.write(sitePaths.gerrit_config, newCfg.toText().getBytes(UTF_8));
+  }
+
+  @Override
+  public String get() {
+    return id;
+  }
+
+  private static Config readGerritConfig(SitePaths sitePaths)
+      throws IOException, ConfigInvalidException {
+    // Reread gerrit.config from disk before writing. We can't just use
+    // cfg.toText(), as the @GerritServerConfig only has gerrit.config as a
+    // fallback.
+    FileBasedConfig cfg = new FileBasedConfig(sitePaths.gerrit_config.toFile(), FS.DETECTED);
+    if (!cfg.getFile().exists()) {
+      return new Config();
+    }
+    cfg.load();
+    return cfg;
+  }
+}