[WIP] RedPanda Operator

How-to start:

make test

or manual testing:

1. Get running cluster (for example using kind)
2. Make sure you kubectl is using correct cluster context.
3. Install CRDs and take care of permissions: make generate && make manifests && make install
4. make run - this will run operator outside k8s cluster for easy troubleshooting.
5. kubectl apply -f testdata/redpanda-cluster.yaml

TODO:

• basic operator using StatefulSet as backend resource.

  • improve testing coverage: see controllers/*_test.go and kubebuilder docs

  • finalizers logic

  • defaulters logic

  • validations

  • scale-out support

  • refactor configuration into templated ConfigMap for operator

  • consider whether using StatefulSets does not limit us:

    Context: Banzai Cloud - Kafka Operator: To StatefulSet or not to StatefulSet: and why it matters

    With StatefulSet we get:
    
    - unique Broker IDs generated during Pod startup
    - networking between brokers with headless services
    - unique Persistent Volumes for Brokers
    
    Using StatefulSet we lose:
    
    - the ability to modify the configuration of unique Brokers
    - to remove a specific Broker from a cluster (StatefulSet always removes the most recently created Broker)
    - to use multiple, different Persistent Volumes for each Broker
    

• other considerations:

  • design operator to be open for multiple backends (AWS K8S Controller, Terraform (?))

• add support for monitoring with Prometheus Operator