Make sure secret type does not get dropped after sealing and unsealing

[linoecarrillo]

This addresses #86 and #87, where the secret type is not persisted throughout the sealing/unsealing process. Secret type used to be persisted before v0.6.0 when the whole secret was being sealed, but is now ignored and lost since only secret.Data key-value pairs are being sealed.

Fixes #86
Fixes #87

[linoecarrillo]

Obviously this still needs some integration tests.

[anguslees]

Tiny and probably zero-impact suggestion, otherwise lgtm!

[anguslees]

Add a // +optional comment telling the autogen machinery that this is optional, just like: https://github.com/kubernetes/api/blob/99b35971cc9d07896d4428dc09ad3efacef8b21f/core/v1/types.go#L4613

[anguslees]

(Thanks for the fix, @linoplt !)

[mgk]

Thanks for the fix! It is working well for us with secrets of type docker-registry and tls.

We've been pointing at latest for now, but would like to peg to a version number. Is a release on the way?

[anguslees]

Is a release on the way?

I want to get #92 merged (in some form) first, since that moves the Type field added in this PR to a more future-proof schema. .. and better to collapse both those changes in a single release cycle, rather than break CRD compatibility in the middle.

Otherwise yes, consider me nagged to hurry up and finish #92 :P