We’ll need to define a _shardsvrRenameCollection request type which we can define in the new rename_collection idl file created as a part of SERVER-42120. We’ll also need to create the new command and should define it in a new file shardsvr_rename_collection.cpp. This command should just call the existing renameCollection command. The new configsvrRenameCollection should call this new command. _shardsvrShardCollection is a good example of the pattern we want to follow.