SERVER-45202 Improve command alias infrastructure

(cherry picked from commit 3cd3a6da3fe0b6f022b721094bda0b97c3527d23)

3 files changed, 40 insertions, 14 deletions

diff --git a/src/mongo/db/commands.cpp b/src/mongo/db/commands.cpp
index b449af1b84a..5ba3eb11db1 100644
--- a/src/mongo/db/commands.cpp
+++ b/src/mongo/db/commands.cpp
@@ -555,11 +555,16 @@ std::unique_ptr<CommandInvocation> BasicCommand::parse(OperationContext* opCtx,
     return stdx::make_unique<Invocation>(opCtx, request, this);
 }
 
-Command::Command(StringData name, StringData oldName)
+Command::Command(StringData name, std::vector<StringData> aliases)
     : _name(name.toString()),
+      _aliases(std::move(aliases)),
       _commandsExecutedMetric("commands." + _name + ".total", &_commandsExecuted),
       _commandsFailedMetric("commands." + _name + ".failed", &_commandsFailed) {
-    globalCommandRegistry()->registerCommand(this, name, oldName);
+    globalCommandRegistry()->registerCommand(this, _name, _aliases);
+}
+
+bool Command::hasAlias(const StringData& alias) const {
+    return globalCommandRegistry()->findCommand(alias) == this;
 }
 
 Status BasicCommand::explain(OperationContext* opCtx,
@@ -610,8 +615,12 @@ bool ErrmsgCommandDeprecated::run(OperationContext* opCtx,
 //////////////////////////////////////////////////////////////
 // CommandRegistry
 
-void CommandRegistry::registerCommand(Command* command, StringData name, StringData oldName) {
-    for (StringData key : {name, oldName}) {
+void CommandRegistry::registerCommand(Command* command,
+                                      StringData name,
+                                      std::vector<StringData> aliases) {
+    aliases.push_back(name);
+
+    for (auto key : aliases) {
         if (key.empty()) {
             continue;
         }
diff --git a/src/mongo/db/commands.h b/src/mongo/db/commands.h
index 1ecd810911c..bade5650496 100644
--- a/src/mongo/db/commands.h
+++ b/src/mongo/db/commands.h
@@ -259,9 +259,15 @@ public:
      * Constructs a new command and causes it to be registered with the global commands list. It is
      * not safe to construct commands other than when the server is starting up.
      *
-     * @param oldName an optional old, deprecated name for the command
+     * @param oldName an old, deprecated name for the command
      */
-    Command(StringData name, StringData oldName = StringData());
+    Command(StringData name, StringData oldName)
+        : Command(name, std::vector<StringData>({oldName})) {}
+
+    /**
+     * @param aliases the optional list of aliases (e.g., old names) for the command
+     */
+    Command(StringData name, std::vector<StringData> aliases = {});
 
     // Do not remove or relocate the definition of this "key function".
     // See https://gcc.gnu.org/wiki/VerboseDiagnostics#missing_vtable
@@ -330,7 +336,7 @@ public:
 
     /**
      * Return true if the command requires auth.
-    */
+     */
     virtual bool requiresAuth() const {
         return true;
     }
@@ -409,10 +415,18 @@ public:
                                      rpc::ReplyBuilderInterface* replyBuilder,
                                      const Command& command);
 
+    /**
+     * Checks if the command is also known by the provided alias.
+     */
+    bool hasAlias(const StringData& alias) const;
+
 private:
     // The full name of the command
     const std::string _name;
 
+    // The list of aliases for the command
+    const std::vector<StringData> _aliases;
+
     // Counters for how many times this command has been executed and failed
     mutable Counter64 _commandsExecuted;
     mutable Counter64 _commandsFailed;
@@ -851,7 +865,7 @@ public:
         return _commands;
     }
 
-    void registerCommand(Command* command, StringData name, StringData oldName);
+    void registerCommand(Command* command, StringData name, std::vector<StringData> aliases);
 
     Command* findCommand(StringData name) const;
 
diff --git a/src/mongo/db/service_entry_point_common.cpp b/src/mongo/db/service_entry_point_common.cpp
index a9a4958701d..a50743e0f1d 100644
--- a/src/mongo/db/service_entry_point_common.cpp
+++ b/src/mongo/db/service_entry_point_common.cpp
@@ -131,7 +131,10 @@ const StringMap<int> sessionCheckoutWhitelist = {{"abortTransaction", 1},
                                                  {"refreshLogicalSessionCacheNow", 1},
                                                  {"update", 1}};
 
-bool shouldActivateFailCommandFailPoint(const BSONObj& data, StringData cmdName, Client* client) {
+bool shouldActivateFailCommandFailPoint(const BSONObj& data,
+                                        const CommandInvocation* invocation,
+                                        Client* client) {
+    auto cmdName = invocation->definition()->getName();
     if (cmdName == "configureFailPoint"_sd)  // Banned even if in failCommands.
         return false;
 
@@ -569,8 +572,7 @@ bool runCommandImpl(OperationContext* opCtx,
 
         auto waitForWriteConcern = [&](auto&& bb) {
             MONGO_FAIL_POINT_BLOCK_IF(failCommand, data, [&](const BSONObj& data) {
-                return shouldActivateFailCommandFailPoint(
-                           data, request.getCommandName(), opCtx->getClient()) &&
+                return shouldActivateFailCommandFailPoint(data, invocation, opCtx->getClient()) &&
                     data.hasField("writeConcernError");
             }) {
                 bb.append(data.getData()["writeConcernError"]);
@@ -635,12 +637,13 @@ bool runCommandImpl(OperationContext* opCtx,
 /**
  * Maybe uassert according to the 'failCommand' fail point.
  */
-void evaluateFailCommandFailPoint(OperationContext* opCtx, StringData commandName) {
+void evaluateFailCommandFailPoint(OperationContext* opCtx, const CommandInvocation* invocation) {
     MONGO_FAIL_POINT_BLOCK_IF(failCommand, data, [&](const BSONObj& data) {
-        return shouldActivateFailCommandFailPoint(data, commandName, opCtx->getClient()) &&
+        return shouldActivateFailCommandFailPoint(data, invocation, opCtx->getClient()) &&
             (data.hasField("closeConnection") || data.hasField("errorCode"));
     }) {
         bool closeConnection;
+        auto commandName = invocation->definition()->getName();
         if (bsonExtractBooleanField(data.getData(), "closeConnection", &closeConnection).isOK() &&
             closeConnection) {
             opCtx->getClient()->session()->end();
@@ -697,7 +700,7 @@ void execCommandDatabase(OperationContext* opCtx,
             replCoord->getReplicationMode() == repl::ReplicationCoordinator::modeReplSet,
             opCtx->getServiceContext()->getStorageEngine()->supportsDocLocking());
 
-        evaluateFailCommandFailPoint(opCtx, command->getName());
+        evaluateFailCommandFailPoint(opCtx, invocation.get());
 
         const auto dbname = request.getDatabase().toString();
         uassert(