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Knative Install on Gardener

This guide walks you through the installation of the latest version of Knative using pre-built images on a Gardener created cluster environment. To set up your own Gardener, see the documentation or have a look at the landscape-setup-template project. To learn more about this open source project, read the blog on kubernetes.io.

You can find guides for other platforms here.

Before you begin

Knative requires a Kubernetes cluster v1.10 or newer.

Install and configure kubectl

  1. If you already have kubectl CLI, run kubectl version --short to check the version. You need v1.10 or newer. If your kubectl is older, follow the next step to install a newer version.

  2. Install the kubectl CLI.

Access Gardener

  1. Create a project in the Gardener dashboard. This will essentially create a Kubernetes namespace with the name garden-<my-project>.

  2. Configure access to your Gardener project using a kubeconfig. If you are not the Gardener Administrator already, you can create a technical user in the Gardener dashboard: go to the "Members" section and add a service account. You can then download the kubeconfig for your project. You can skip this step if you create your cluster using the user interface; it is only needed for programmatic access, make sure you set export KUBECONFIG=garden-my-project.yaml in your shell. Download kubeconfig for Gardener

Creating a Kubernetes cluster

You can create your cluster using kubectl cli by providing a cluster specification yaml file. You can find an example for GCP here. Make sure the namespace matches that of your project. Then just apply the prepared so-called "shoot" cluster crd with kubectl:

kubectl apply --filename my-cluster.yaml

The easier alternative is to create the cluster following the cluster creation wizard in the Gardener dashboard: shoot creation

Configure kubectl for your cluster

You can now download the kubeconfig for your freshly created cluster in the Gardener dashboard or via cli as follows:

kubectl --namespace shoot--my-project--my-cluster get secret kubecfg --output jsonpath={.data.kubeconfig} | base64 --decode > my-cluster.yaml

This kubeconfig file has full administrators access to you cluster. For the rest of this guide be sure you have export KUBECONFIG=my-cluster.yaml set.

Installing Istio

Knative depends on Istio.

  1. Install Istio: 
    kubectl apply --filename https://github.com/knative/serving/releases/download/v0.2.2/istio.yaml
  2. Label the default namespace with istio-injection=enabled: 
    kubectl label namespace default istio-injection=enabled
  3. Monitor the Istio components until all of the components show a STATUS of Running or Completed: bash kubectl get pods --namespace istio-system

It will take a few minutes for all the components to be up and running; you can rerun the command to see the current status.

Note: Instead of rerunning the command, you can add --watch to the above command to view the component's status updates in real time. Use CTRL + C to exit watch mode.

Installing Knative components

You can install the Knative Serving and Build components together, or Build on its own.

Installing Knative Serving and Build components

  1. Run the kubectl apply command to install Knative and its dependencies: 
    kubectl apply --filename https://github.com/knative/serving/releases/download/v0.2.2/release.yaml
  2. Monitor the Knative components until all of the components show a STATUS of Running: 
    kubectl get pods --namespace knative-serving
kubectl get pods --namespace knative-build

Installing Knative Build only

  1. Run the kubectl apply command to install Knative Build and its dependencies: 
    kubectl apply --filename https://github.com/knative/serving/releases/download/v0.2.2/build.yaml
  2. Monitor the Knative Build components until all of the components show a STATUS of Running: 
    kubectl get pods --namespace knative-build

Just as with the Istio components, it will take a few seconds for the Knative components to be up and running; you can rerun the kubectl get command to see the current status.

Note: Instead of rerunning the command, you can add --watch to the above command to view the component's status updates in real time. Use CTRL + C to exit watch mode.

You are now ready to deploy an app or create a build in your new Knative cluster.

Alternative way to enable Knative with Gardener

Ask your Gardener administrator to configure the Gardener Bouquet addon manager with the following CRDs:

apiVersion: "garden.sapcloud.io/v1alpha1"
kind: "AddonManifest"
metadata:
  name: "istio-1.0.2"
  finalizers:
    - "bouquet"
spec:
  configMap: "istio-chart-080"

apiVersion: "garden.sapcloud.io/v1alpha1"
kind: "AddonManifest"
metadata:
  name: "knative-0.0.1"
  finalizers:
    - "bouquet"
spec:
  configMap: "knative-chart-001"
  dependencies:
    istio: "1.0.2"

And of course create the respective ConfigMaps:

curl https://github.com/knative/serving/releases/download/v0.2.2/istio.yaml
kubectl create configmap istio-chart-080 --from-file=istio.yaml

curl https://github.com/knative/serving/releases/download/v0.2.2/release.yaml
kubectl create configmap knative-chart-001 --from-file=release.yaml

With this preparation, your team can just activate Knative in the "Addons" tab when creating a new cluster: alt text

Set your custom domain

  1. Fetch the external IP or CNAME of the knative-ingressgateway
kubectl --namespace istio-system get service knative-ingressgateway
NAME                     TYPE           CLUSTER-IP      EXTERNAL-IP     PORT(S)                                      AGE
knative-ingressgateway   LoadBalancer   100.70.219.81   35.233.41.212   80:32380/TCP,443:32390/TCP,32400:32400/TCP   4d
  1. Create a wildcard DNS entry in your custom domain to point to above IP or CNAME
*.knative.<my domain> == A 35.233.41.212
# or CNAME if you are on AWS
*.knative.<my domain> == CNAME a317a278525d111e89f272a164fd35fb-1510370581.eu-central-1.elb.amazonaws.com
  1. Adapt your knative config-domain (set your domain in the data field)
kubectl --namespace knative-serving get configmaps config-domain --output yaml
apiVersion: v1
data:
  knative.<my domain>: ""
kind: ConfigMap
  name: config-domain
  namespace: knative-serving

Deploying an app

Now that your cluster has Knative installed, you're ready to deploy an app.

If you'd like to follow a step-by-step guide for deploying your first app on Knative, check out the Getting Started with Knative App Deployment guide.

If you'd like to view the available sample apps and deploy one of your choosing, head to the sample apps repo.

Cleaning up

Use the Gardener dashboard to delete your cluster, or execute the following with kubectl pointing to your garden-my-project.yaml kubeconfig:

kubectl --kubeconfig garden-my-project.yaml --namespace garden--my-project annotate shoot my-cluster confirmation.garden.sapcloud.io/deletion=true

kubectl --kubeconfig garden-my-project.yaml --namespace garden--my-project delete shoot my-cluster

Except as otherwise noted, the content of this page is licensed under the Creative Commons Attribution 4.0 License, and code samples are licensed under the Apache 2.0 License.