Create a kind K8s cluster with Knative Serving for development purposes

knative-serving-kind.sh

#!/usr/bin/env bash
#
# Copyright 2020 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# Disclaimer: This is not an officially supported Google product.
#
# Create a kind cluster with Knative Serving and Istio.
#
# It's a minimal installation in order to keep resource consumption low:
# - use Istio lean (Pilot + Ingress gateway only, no sidecar injection)
# - doesn't install the monitoring component
# - only one replica for each deployment
# - pod resource requests and limits removed
# - HPAs removed, or minReplicas set to 1
#
# For development only, not for production!
#
# Requires `kind` and `yq`:
#   GO111MODULE=on go get sigs.k8s.io/kind@v0.6.1
#   GO111MODULE=on go get github.com/mikefarah/yq/v2@v2.4.1
# Optionally:
#   GO111MODULE=on go get knative.dev/client/cmd/kn@v0.11.0

set -euf -o pipefail

CLUSTER=${CLUSTER:-knative}
KNATIVE_SERVING_VERSION=${KNATIVE_SERVING_VERSION:-v0.11.1}
ISTIO_VERSION=${ISTIO_VERSION:-1.4.0}

# Create a kind cluster

kind create cluster --name "$CLUSTER"

# Install Istio

kubectl apply -f "https://raw.githubusercontent.com/knative/serving/${KNATIVE_SERVING_VERSION}/third_party/istio-${ISTIO_VERSION}/istio-crds.yaml"

echo Waiting for Istio CRDs to be ready...
until kubectl get crds/gateways.networking.istio.io 2> /dev/null; do sleep 3; done

# The next command uses sed to remove the three HPAs at the end of the manifest.
# That's brittle. Verify that this doesn't break anything when upgrading Istio.

curl -sL "https://raw.githubusercontent.com/knative/serving/${KNATIVE_SERVING_VERSION}/third_party/istio-${ISTIO_VERSION}/istio-lean.yaml" \
    | yq d -d'*' - 'spec.replicas' \
    | yq d -d'*' - 'spec.template.spec.containers[*].resources' \
    | yq d -d'*' - 'spec.minReplicas' \
    | sed '/apiVersion\: autoscaling\/v2beta1/,$d' \
    | kubectl apply -f -

# Install Knative Serving

kubectl apply -f "https://github.com/knative/serving/releases/download/${KNATIVE_SERVING_VERSION}/serving-crds.yaml"

echo Waiting for Knative Serving CRDs to be ready
until kubectl get crds/services.serving.knative.dev 2> /dev/null; do sleep 3; done

curl -sL "https://github.com/knative/serving/releases/download/${KNATIVE_SERVING_VERSION}/serving.yaml" \
    | yq d -d'*' - 'spec.replicas' \
    | yq d -d'*' - 'spec.template.spec.containers[*].resources' \
    | yq d -d'*' - 'spec.minReplicas' \
    | kubectl apply -f -

echo Waiting for the Istio Ingress Gateway deployment to be ready
kubectl -n istio-system rollout status deploy/istio-ingressgateway
echo Waiting for the Knative Serving controller deployment to be ready
kubectl -n knative-serving rollout status deploy/controller

# Reduce queue-proxy logging output so we don't get lots of probe spam in the Skaffold log output

kubectl -n knative-serving patch cm/config-logging -p '{"data": {"loglevel.queueproxy": "warn"}}'

echo
echo '*****************************************************************************'
echo "kind cluster $CLUSTER with Knative Serving $KNATIVE_SERVING_VERSION and Istio v$ISTIO_VERSION is ready."
echo '*****************************************************************************'
echo
echo Pull non-public images from gcr.io:
echo
echo 'SA_EMAIL="$(gcloud iam service-accounts create gcr-pull --format "value(email)")"'
echo 'PROJECT_ID="$(gcloud config list --format="value(core.project)")"'
echo 'gsutil iam ch "serviceAccount:${SA_EMAIL}:objectViewer" "gs://artifacts.${PROJECT_ID}.appspot.com"'
echo 'gcloud iam service-accounts keys create gcr-pull-credentials.json --iam-account "$SA_EMAIL"'
echo 'set +o history'
echo 'kubectl create secret docker-registry gcr-pull \'
echo '    --docker-email="${SA_EMAIL}" \'
echo '    --docker-password="$(cat ./gcr-pull-credentials.json)" \'
echo '    --docker-server=gcr.io \'
echo '    --docker-username=_json_key'
echo 'set -o history'
echo 'kubectl patch sa default -p "{\"imagePullSecrets\": [{\"name\": \"gcr-pull\"}]}"'
echo
echo Deploy a sample service:
echo
echo 'kn service create helloworld --image=gcr.io/knative-samples/simple-api'
echo
echo Set up port forwarding to the Istio ingress gateway:
echo
echo 'kubectl -n istio-system port-forward svc/istio-ingressgateway 8080:80'
echo