Allow providing control plane certs & ca in separate secrets

[usrbinkat]

Summary

Effective declarative deployment via helm is negatively impacted due to Control Plane certificate strategy requiring cert, key, and CA to come from a single secret. An example scenario is the difficulty issuing controlplane ca and certificates via cert-manager.

Steps To Reproduce

1. Create CA with Cert Manager
2. Issue Control Plane Cert & Key with Cert Manager
3. Deploy Kuma via Helm pointing at the issued cert/key
4. Observe Control Plane deployment failure due to secret not including CA

Workaround

• A) Anti-pattern
  2.a Issue Control Plane Cert & Key with Cert Manager
  2.b Concatenate CA, Cert, and Key into single secret prior to helm deploying Kuma
  3.a Deploy Kuma via Helm pointing at the concatenated ca/cert/key secret
• B) Snowflake
  • Implement Kustomize patching to accomodate independent Cert Manager provided certs

Additional Details & Logs

• Installation Method Helm

[scottslowe]

Strongly support this RFE. More details on the anti-pattern described by @usrbinkat can be found here: https://github.com/scottslowe/kuma-cert-manager