[DOC] Add new section on Kafka Bridge

[d-laing]

Type of change

• Documentation

Description

This pull request adds a new chapter on the Strimzi Kafka Bridge to introduce the Bridge and provide information on clients, data formats, encryption, etc.

The content links to the new content in #1665 where appropriate.

Deploying the Bridge will be documented in a separate PR as this will be documented in chapter 2, Getting Started.

Checklist

Please go through this checklist and make sure all applicable tasks have been done

• Update/write design documentation in ./design
• Write tests
• Make sure all tests pass
• Update documentation
• Check RBAC rights for Kubernetes / OpenShift roles
• Try your changes from Pod inside your Kubernetes and OpenShift cluster, not just locally
• Reference relevant issue(s) and close them after merging
• Update CHANGELOG.md

[d-laing]

I decided to create a new concept on "Requests to the Kafka Bridge". @ppatierno - Please review the new content on "Data formats and headers": documentation/book/con-requests-kafka-bridge.adoc

[d-laing]

• Removed the unfinished modules and added cross-refs to [DOC] Add new section on Kafka Bridge #1668 where appropriate, e.g. the deployment instructions. I decided to remove the "Sending Requests" module from the scope of this PR.
• Incorporated Jakub's content on "Securing the HTTP Kafka Bridge".
• Added a new module for Jakub's content on "Accessing the HTTP Kafka Bridge from outside of Kubernetes/Openshift"

@ppatierno - Please can you give this a final check and confirm if it's ready to merge?

[d-laing]

@scholzj - Please can you give this a second review and confirm if it's ready to merge? I made the change in terminology to "HTTP clients" as you suggested in PR#51.

I've included your content on "Securing the HTTP Kafka Bridge" and "Accessing the HTTP Kafka Bridge from outside of Kubernetes/Openshift". Thanks.

[scholzj]

Some minors. But LGTM otherwise.

[scholzj]

The kafka-bridge-name has to be replaced by the actual name of the CR. Do we will mark the things which should be replaced as <kafka-bridge-name>? Or just mark it with this <1> and explain below it how it should be replaced like you do on other places.

[d-laing]

I think we're a bit inconsistent in our approach. I like using annotations in the YAML examples. I'll add a <1> annotation and an explanation.

[scholzj]

Should we link here also to con-accessing-kafka-bridge-from-outside-{context}?

[d-laing]

Agreed. I'll add an Additional resources section to the module.