I unzipped the current nodejs to / opt/app/node-v8.11.4-linux-x64
-sharp
ln -s /opt/app/node-v8.11.4-linux-x64/bin/node /usr/local/bin/
has no effect on executing node-v,
(not even using ln-s / opt/app/node-v8.11.4-linux-x64/bin/node / usr/local/bin/node)