Refactor in light of growth

[cyclingwithelephants]

With new resources being added and further resources being requested I'd like to propose some refactoring with the intent to make delivering and maintaining these easier down the line:

• move separate controllers into their own packages

Once this is done, it will be easier to pull out common interfaces and reason about them, the most obvious changes to me are:

• move (very gradually) towards a clean architecture approach, to aid in unit testing:
  • in the first instance I think that'd mean converting dependencies on the cloudflare API into an interface and depending on that interface
  • similarly I'd like to hide touching kubernetes behind an interface

You know this code base better than me, so is there anything I've missed that's on your radar?

[adyanth]

move separate controllers into their own packages

Interesting, the access tunnel can surely be moved, but the rest of them are bound together because they share functionality. I am open to moving what is currently present into two separate packages, and Cloudflare api to its own (combining with the utils)

Very much supportive of breaking it down for ease of testing, when I started this out, I was not familiar with testing strategies, let alone testing controllers in go. It is very much due a refactor.

The only thing I was thinking of was coming up with a better abstraction for Tunnel+ClusterTunnel sharing functionality other than the current Tunnel and Adapter scheme.