Stream Content to Chromecast from Linux
Well, here are some of the options available.
Official Google Chrome Web Browser Google Cast Extension
Stream tab content from within a Google Chome Web browser tab to your Chromecast. Works with Netflix, the Google Play store, YouTube, and more. Just install the Google Cast extension and you're good to go.
I've stumbled on a nifty little tool that will stream just about anything to a Chromecast, aptly called castnow. This handy little tool will stream content directly to your Chromecast that's either local or remote. Put your Chromecast in guest mode for this to work without any configuration.
To get this Node.js application running, I had to Install Node.js on Ubuntu 16.