knative-serving-operator

Knative Serving Operator

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

kubectl apply -f deploy/crds/serving_v1alpha1_install_crd.yaml
kubectl apply -f deploy/
kubectl apply -f deploy/crds/serving_v1alpha1_install_cr.yaml

Prerequisites

Istio

Version 0.5.x of Knative Serving requires Istio CRD's:

kubectl apply -f https://github.com/knative/serving/releases/download/v0.5.2/istio-crds.yaml

Operator SDK

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

The Install Custom Resource

The installation of Knative Serving is triggered by the creation of an Install custom resource.

The optional spec.namespace field denotes the target namespace for the installation, and the optional spec.config field can be used to set the corresponding entries in the Knative Serving ConfigMaps. The status field will contain a list of the resources the operator installs and their version.

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

kubectl get installs.serving.knative.dev -oyaml
kubectl get ksi -oyaml
kubectl get install -oyaml

To uninstall Knative Serving, simply delete the Install resource.

kubectl delete ksi --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

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/$REPO/knative-serving-operator:$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 CatalogSource

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

The catalog.sh script should yield a valid CatalogSource for you to publish.

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 Serving into the knative-serving namespace, apply the following resources:

cat <<-EOF | kubectl apply -f -
---
apiVersion: v1
kind: Namespace
metadata:
  name: knative-serving
---
apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
  name: knative-serving
  namespace: knative-serving
---
apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: knative-serving-operator-sub
  generateName: knative-serving-operator-
  namespace: knative-serving
spec:
  source: knative-serving-operator
  sourceNamespace: olm
  name: knative-serving-operator
  channel: alpha
---
apiVersion: serving.knative.dev/v1alpha1
kind: Install
metadata:
  name: knative-serving
  namespace: knative-serving
EOF