Allow showing just the current leader in raft-info

src/raft/RaftDispatcher.cc

@@ -43,6 +43,10 @@ LinkStatus RaftDispatcher::dispatch(Connection *conn, RedisRequest &req) {
   switch(req.getCommand()) {
     case RedisCommand::RAFT_INFO: {
       // safe, read-only request, does not need authorization
+      if(req.size() == 2 && caseInsensitiveEquals(req[1], "leader")) {
+        return conn->string(state.getSnapshot()->leader.toString());
+      }
+
       return conn->statusVector(this->info().toVector());
     }
     case RedisCommand::RAFT_FETCH_LAST: {

test/e2e.cc

@@ -425,6 +425,7 @@ TEST_F(Raft_e2e, test_many_redis_commands) {
   futures.emplace_back(tunnel(leaderID)->exec("bad_command"));
   futures.emplace_back(tunnel(leaderID)->exec("exists", "hash"));
   futures.emplace_back(tunnel(leaderID)->exec("exists", "hash2"));
+  futures.emplace_back(tunnel(leaderID)->exec("raft_info", "leader"));
 
   ASSERT_REPLY(futures[0], 1);
   ASSERT_REPLY(futures[1], 1);
@@ -434,6 +435,7 @@ TEST_F(Raft_e2e, test_many_redis_commands) {
   ASSERT_REPLY(futures[5], "ERR unknown command 'bad_command'");
   ASSERT_REPLY(futures[6], 0);
   ASSERT_REPLY(futures[7], 1);
+  ASSERT_REPLY(futures[8], myself(leaderID).toString() );
 
   futures.clear();
   futures.emplace_back(tunnel(leaderID)->exec("hmset", "hmset_test", "f1", "v1", "f2", "v2"));