Avoid cross reference between applications

[dalonsoa]

In the interest of not blocking this further, leave it as as and open an issue about it.

I think the way we've been doing this is to put any common functionality between the apps into the main app (although I don't know if this actually is better for splitting things down the line)

Originally posted by @AdrianDAlessandro in #262 (comment)

At the moment, the controller app needs to import the process manager app in order to get the hostname information. That's not ideal. The best solution is unclear, but could consist on putting the get_hostname functionality in the main app.