SERVER-30080 LogicalSessions in the shell

Basic logical session implementation for the shell

1 files changed, 14 insertions, 0 deletions

diff --git a/src/mongo/client/dbclient.cpp b/src/mongo/client/dbclient.cpp
index 6e95116c13e..74d26aac7d5 100644
--- a/src/mongo/client/dbclient.cpp
+++ b/src/mongo/client/dbclient.cpp
@@ -38,6 +38,7 @@
 
 #include "mongo/base/status.h"
 #include "mongo/base/status_with.h"
+#include "mongo/bson/util/bson_extract.h"
 #include "mongo/bson/util/builder.h"
 #include "mongo/client/authenticate.h"
 #include "mongo/client/constants.h"
@@ -774,6 +775,19 @@ Status DBClientConnection::connect(const HostAndPort& serverAddress, StringData
         return swProtocolSet.getStatus();
     }
 
+    {
+        std::string msgField;
+        auto msgFieldExtractStatus = bsonExtractStringField(swIsMasterReply.data, "msg", &msgField);
+
+        if (msgFieldExtractStatus == ErrorCodes::NoSuchKey) {
+            _isMongos = false;
+        } else if (!msgFieldExtractStatus.isOK()) {
+            return msgFieldExtractStatus;
+        } else {
+            _isMongos = (msgField == "isdbgrid");
+        }
+    }
+
     auto validateStatus =
         rpc::validateWireVersion(WireSpec::instance().outgoing, swProtocolSet.getValue().version);
     if (!validateStatus.isOK()) {