Knative Cluster Setup

Quick setup guide follow this and other docs and blogs to get a knative cluster working.

See knative release pages:

Create Kubernetes Cluster

** Docker for mac doesn't work with Knative 0.5.0 (requries Kubernetes version 1.11) **

Dependency versions for local kube:

minikube version: v1.0.0
kubernetes version: v1.14.1
virtualbox version: 6.0.4
hyperkit version: 0.20180403

Start

minikube start --memory=8192 --cpus=4 \
--kubernetes-version=v1.14.1 \
--vm-driver=hyperkit \
--disk-size=30g \
--extra-config=apiserver.enable-admission-plugins="LimitRanger,NamespaceExists,NamespaceLifecycle,ResourceQuota,ServiceAccount,DefaultStorageClass,MutatingAdmissionWebhook"

Check kubernetes is running:

kubectl cluster-info

Knative components

knative version: 0.5.0

Knative is setup with 5 separate components (you don't have to use them all).

Istio - load balancer, routing, and service mesh for kube and consul (alternatively use gloo)
Serving - serves your application, includes activator and autoscaler
Build - defined by build templates and builds
Eventing - cluster events, webhooks, build triggers
Monitoring - prometheus, grafana, elasticsearch, kibana, fluentd, zipkin,

Istio

Run these

kubectl apply --filename istio-crds.yaml 
kubectl apply --filename istio.yaml

Check all services are up and running (takes about 5 mins):

kubectl get pods --namespace istio-system

Enable istio injection into your default namespace (application)

kubectl label namespace default istio-injection=enabled

Check default namespace allows istio injection

kubectl get namespace -L istio-injection

```
NAME                 STATUS   AGE   ISTIO-INJECTION
default              Active   12m   enabled
istio-system         Active   12m   disabled
```

Knative

Install serving, build, eventing

kubectl apply --filename serving.yaml 
kubectl apply --filename build.yaml 
kubectl apply --filename release.yaml 
kubectl apply --filename eventing-sources.yaml 
kubectl apply --filename monitoring.yaml 
kubectl apply --filename clusterrole.yaml

Wait 10 mins for all pods to be running or complete, keep checking with these commands

kubectl get pods --namespace knative-serving
kubectl get pods --namespace knative-build
kubectl get pods --namespace knative-eventing
kubectl get pods --namespace knative-sources
kubectl get pods --namespace knative-monitoring

** re-run commands if errors, I experienced many issues with incorrect versions and not following the correct order of installation or not waiting for everything to be running. **

Application

Hello world go app

kubectl apply --filename service.yaml

To test, it get dirty, first you need to know the cluster ip address and ingress gateway port number, then you need to know the virtual host name so you can add it as a header to the request.

Virtual hostname will be: ..example.com

export IP_ADDRESS=$(kubectl get node -o 'jsonpath={.items[0].status.addresses[0].address}')
export PORT_NUMBER=$(kubectl get svc istio-ingressgateway --namespace istio-system -o 'jsonpath={.spec.ports[?(@.port==80)].nodePort}')
export VIRTUAL_HOST_URL=$(kubectl get route helloworld-go  --output jsonpath='{.status.domain}')

curl -H "Host: $VIRTUAL_HOST_URL" $IP_ADDRESS:$PORT_NUMBER

Response:

> GET / HTTP/1.1
> Host: helloworld-go.default.example.com

< HTTP/1.1 200 OK
< content-length: 20
< content-type: text/plain; charset=utf-8
< server: envoy

Hello Go Sample v1!