Knative Kafka Operator

The following will install Knative Kafka and configure it appropriately for your cluster in the default namespace:

kubectl apply -f deploy/crds/eventing_v1alpha1_knativeeventingkafka_crd.yaml
kubectl apply -f deploy/
kubectl apply -f deploy/crds/eventing_v1alpha1_knativeeventingkafka_cr.yaml

Prerequisites

Apache Kafka

This operator installs components that access Apache Kafka, therefore you MUST have a running cluster of Apache Kafka somewhere.

• For Kubernetes a simple installation is done using the Strimzi Kafka Operator. Its installation guides provide content for Kubernetes and Openshift.

Operator SDK

This operator was created using the operator-sdk. It's not strictly required but does provide some handy tooling.

The KnativeEventingKafka Custom Resource

The installation of Knative Kafka is triggered by the creation of an KnativeEventingKafka custom resource.

The following are all equivalent, but the latter may suffer from name conflicts.

kubectl get knativeventingkafka.eventing.knative.dev -oyaml
kubectl get kek -oyaml
kubectl get knativeventingkafka -oyaml

To uninstall Knative Kafka, simply delete the KnativeEventingKafka resource.

kubectl delete kek --all

Development

It can be convenient to run the operator outside of the cluster to test changes. The following command will build the operator and use your current "kube config" to connect to the cluster:

operator-sdk up local --namespace=""

Pass --help for further details on the various operator-sdk subcommands, and pass --help to the operator itself to see its available options:

operator-sdk up local --operator-flags "--help"

Building the Operator Image

To build the operator,

operator-sdk build quay.io/$REPO/knative-kafka-operator:$VERSION

The image should match what's in deploy/operator.yaml and the $VERSION should match version.go and correspond to the contents of deploy/resources.

There is a handy script that will build and push an image to quay.io and tag the source:

./hack/release.sh

Operator Framework

The remaining sections only apply if you wish to create the metadata required by the Operator Lifecycle Manager

Create a ClusterServiceVersion

The OLM requires special manifests that the operator-sdk can help generate.

Create a ClusterServiceVersion for the version that corresponds to the manifest[s] beneath deploy/resources. The $PREVIOUS_VERSION is the CSV yours will replace.

operator-sdk olm-catalog gen-csv \
    --csv-version $VERSION \
    --from-version $PREVIOUS_VERSION \
    --update-crds

Most values should carry over, but if you're starting from scratch, some post-editing of the file it generates may be required:

• Add fields to address any warnings it reports
• Verify description and displayName fields for all owned CRD's

Create a CatalogSource

The catalog.sh script should yield a valid ConfigMap and CatalogSource comprised of the ClusterServiceVersions, CustomResourceDefinitions, and package manifest in the bundle beneath deploy/olm-catalog. You should apply its output in the OLM namespace:

OLM=$(kubectl get pods --all-namespaces | grep olm-operator | head -1 | awk '{print $1}')
./hack/catalog.sh | kubectl apply -n $OLM -f -

Using OLM on Minikube

You can test the operator using minikube after installing OLM on it:

minikube start
kubectl apply -f https://github.com/operator-framework/operator-lifecycle-manager/releases/download/0.9.0/olm.yaml

Once all the pods in the olm namespace are running, install the operator like so:

./hack/catalog.sh | kubectl apply -n $OLM -f -

Interacting with OLM is possible using kubectl but the OKD console is "friendlier". If you have docker installed, use this script to fire it up on http://localhost:9000.

Using kubectl

To install Knative Kafka into the knative-eventing namespace, apply the following resources:

cat <<-EOF | kubectl apply -f -
---
apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: knative-kafka-operator-sub
  generateName: knative-kafka-operator-
  namespace: $OPERATOR_NS
spec:
  source: knative-kafka-operator
  sourceNamespace: $OLM
  name: knative-kafka-operator
  channel: alpha
---
apiVersion: eventing.knative.dev/v1alpha1
kind: KnativeEventingKafka
metadata:
  name: knative-eventing-kafka
spec:
  bootstrapServers: my-cluster-kafka-bootstrap.kafka:9092
  #setAsDefaultChannelProvisioner: yes
EOF