Add proposal for supporting SSL for KafkaBridge

[tinaselenge]

POC:
https://github.com/strimzi/strimzi-kafka-bridge/compare/main...tinaselenge:strimzi-kafka-bridge:ssl-support?expand=1
https://github.com/strimzi/strimzi-kafka-operator/compare/main...tinaselenge:bridge-ssl?expand=1

Related to strimzi/strimzi-kafka-bridge#939

[scholzj]

Just some quick thoughts.

[scholzj]

The way we setup the certificates seems also important to whether we ever expect to have some better scalability or not I guess.

[tinaselenge]

The way we setup the certificates seems also important to whether we ever expect to have some better scalability or not I guess.

With this proposal, the same certificate and key (via referenced secret in the CR) will be volume mounted into each KafkaBridge pod if it is scaled to multiple replicas, which is not different than how TLS authentication is configured for KafkaBridge talking to Kafka. My understanding is that KafkaBridge is not truly scalable in terms of consumers, but I'm not sure what is the expectation at the moment, in terms of improving that and what to consider for the certificate setup.

[tinaselenge]

I've marked this as ready for review now :)

[im-konge]

Thanks for the proposal, it looks good to me, just few small things.

[im-konge]

LGTM, thanks a lot Tina :)

[scholzj]

Few more nits. Mostly formatting. The only real point for discussion is about the SSL protocols. Looks good otherwise.

[scholzj]

Thanks. LGTM, +1 binding.

[tinaselenge]

Thank you so much @scholzj @im-konge!

@ppatierno could you please take another look when you get a chance? Thank you!

@PaulRMellor @katheris could you please also take a look if you have time? Thank you!

[PaulRMellor]

Thanks, Tina.
I made some suggestions as I read though.
I wonder if the proposal would benefit from mentioning requirements for documentation and testing?

[katheris]

Overall this makes sense to me, I just added some clarification and wording comments

[PaulRMellor]

Thanks for the updates, Tina