Make child resource creation atomic when creating a k8s stack

[simonferquel]

- What I did

I made sure that configs and secrets created with the CLI are

• correctly removed if the stack itself can't be created (validation error,...)
• have their owner reference set to the stack when the stack is correctly created

- How I did it

• added a childResource interface, with setOwner and delete functions
• keep track of all created childResources

- How to verify it

The PR comes with unit tests

[codecov-io]

Codecov Report

Merging #1611 into master will increase coverage by 0.4%.
The diff coverage is 75.53%.

@@            Coverage Diff            @@
##           master    #1611     +/-   ##
=========================================
+ Coverage   55.16%   55.56%   +0.4%     
=========================================
  Files         301      301             
  Lines       20384    20451     +67     
=========================================
+ Hits        11244    11363    +119     
+ Misses       8335     8270     -65     
- Partials      805      818     +13

[simonferquel]

@silvin-lubecki @vdemeester PTAL :)

[silvin-lubecki]

I think you can factorize the check on OwnerReferences with the next test.

[silvin-lubecki]

+12k for the vendoring... only for fakes... 😱
Are you sure it's mandatory?

[simonferquel]

Fakes are a VERY useful way to test integration with the Kubernetes API, which let us use the existing client-go abstractions without having to write our own fakes. There is a tradeoff there: vendoring the whole thing makes test setup far easier (and cleaner). We could also partially vendor fakes for supporting only the Core API (configs and secrets are in the Core API), but that would require some code change and a more complex test setup. We could also don't vendor the fakes and write our own (but I strongly discourage it).

[silvin-lubecki]

LGTM

[vdemeester]

LGTM 🌮