A friend of mine is looking for something that can sit, permanently plugged into his hi-fi system, with his external hard drive attached (containing his entire music library) that can be controlled via his iPad over his wifi network.  I realise that one solution is to use a raspberry pi as a sort of music server, the problem with this is that he's not experienced with linux or coding and therefore I'm not convinced this is the best option for him as it would require some tinkering to get setup.  Another solution that we considered was to get a cloud hard drive that would connect to the wifi network and could be accessed from any device connected to the network (i.e. his iPad) but then this still needs another device connected to hi-fi (such as a chromecast audio) that can then play the audio stream.  I feel like there must be a single device that can do this as it must be a common problem.  Obviously he could buy a music server but they are quite expensive and essentially he doesn't need something so overcomplicated, it just needs to connect to the wifi and have a usb port for the hard drive. Any suggestions are welcome but single device solutions would be greatly preferred. 
Cheap, small, music server
wifi;music