How to factorize code between kops and cluster api?

[remyleone]

/kind feature

1. Describe IN DETAIL the feature/behavior/change you would like to see.

I would like to have documentation about how to have reusable components between kops and cluster api controller. For those both tools there is a lot of overlap in the preparation of a cluster. Is there any documentation/recommendation about how to reuse code between those two projects?

2. Feel free to provide a design supporting your feature request.

I would like to have documentation about the core functions/interfaces that would need to be documented to permit maximum reusability between kops and cluster api.

[hakman]

/assign @justinsb
/kind office-hours