I was able to get sharp working by simply building it locally.npm install --build-from-source sharp
The only thing missing on my minimal centos 7 image, was g++.
I was wondering how I put a folder with some NodeJS scripts in it on the same server running NodeBB at the same time. I'm unsure where to put the folder or if I need to configure NodeJS as a HTTP server while keeping NodeBB in the same place.
We'll need to know exactly what the api is you're trying to install to be sure.
But generally, it's probably going to be running as a separate node process, using a screen session, the actual location of the folder won't matter. The app should have a config setting to set the listening port (or have a default port), and in your nginx/apache config, you'll need to redirect the api routes used by the app from port 80 to the app's configured port. Very similar to NodeBB itself.
Thats the API. I need it to run on the same place as a NodeBB forum running on port 80.
Just read something. I need to run it as a Linux app.
Well... If you already have NodeBB running on port 80 without nginx/Apache proxy, then you can not assign another service on the port as well. I recommend you to set up an nginx/Apache proxy for NodeBB and create virutal hosts for each service you want to run on port 80 (this way you can run multiple services/sites on port 80).