expose kubeconfig hash

[mindovermiles262]

Sometimes you need to access the raw kube_config hash. This PR adds a method to do so

[cben]

Thanks. Generally makes sense, I don't think the instance var was deliberately private 👍

Note that this exposes the original data from kubeconfig file, before all the work done by .context() to resolve data:

• referenced external files will not be inlined (e.g. you may see certificate-authority file name vs. inline certificate-authority-data).
• active credential sources ExecCredentials / GCPAuthProvider / OIDCAuthProvider will not run.
• the data will be static. This matters because in future we'll want to support auth renewal Authentication renewal #393, which besides expiration on above active sources requires re-reading the kubeconfig file (or files referenced from it) when updated.
  • EDIT: Similarly, when given fixed :bearer_token_file path, we need to reload its content periodically. bearer_token needs to be reloaded every 1h to avoid expired service account tokens #530 / Kubernetes1.21 BoundServiceAccountToken Support #561

If you have use case for it with these caveats, LGTM, but please add documentation in README.

Is .kube_config clear name for the as-is parsed yaml?
What do you think of something like .to_hash, or maybe .parsed_data / .parsed / .as_parsed to be similar to Client's as: :parsed mode? (not sure these are better, just throwing out ideas...)

[cben]

@mindovermiles262 The question still stands — do you think this will be useful with the caveats listed above?

• One change since then: we've implemented bearer_token_file auto-reloading in Client (but not an inline bearer_token).
  IIRC, bearer_token_file reloading happens just before making a request, so you'll not see it reflected in Config's hash. You'll see a static file path there, because as I said this returns the parsed yaml as-is, before resolving external file references.

Or should we close this? What's is your use case for accessing the raw config?

[mindovermiles262]

I do not remember why I needed the raw kube config. You're OK to do as you wish with this PR.