How to add library search path on Alpine Linux? ldconfig

I'm trying to build a dockerfile for installing saprfc on an Alpine linux base image. The instructions say to create /etc/ld.so.conf.d/nwrfcsdk.conf and to put /usr/local/sap/nwrfcsdk/lib in the nwrfcsdk.conf file. ldconfig should then load the saprfc libraries. However, I have learned that ldconfig on Alpine does not read from ld.so.conf.d. ldconfig -p is also not a recognized option. So how do you add a custom library search path on Alpine Linux?