Playground
This guide will help you set up a local Kubernetes cluster to test the elasti operator and resolver. Follow these steps from the project home directory.
1. Local Cluster
If you don't already have a local Kubernetes cluster, you can set one up using Minikube, Kind or Docker-Desktop:
2. Start a Local Docker Registry
Run a local Docker registry container, to push our images locally and access them in our cluster.
docker run -d --restart=always -p 5001:5000 --name kind-registry registry:2;
# If you are using kind, connect the registry to kind network
docker network create kind
docker network connect "kind" kind-registry
Add registry to Minikube and Kind
You will need to add this registry to Minikube and Kind. With Docker-Desktop, it is automatically picked up.
In MacOS, 5000 is not available, so we use 5001 instead.
3. Build & Publish Resolver & Operator
Once you have made the necessary changes to the resolver or operator, you can build and publish it using the following commands:
make -C resolver docker-build docker-push IMG=localhost:5001/elasti-resolver:v1alpha1
make -C operator docker-build docker-push IMG=localhost:5001/elasti-operator:v1alpha1
Make sure you have configured the local context in kubectl. With kind, it is automatically picked up,
4. Setup Prometheus
We will setup a sample prometheus to read metrics from the ingress controller.
helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
helm repo update
helm install kube-prometheus-stack prometheus-community/kube-prometheus-stack \
--namespace monitoring \
--create-namespace \
--set alertmanager.enabled=false \
--set grafana.enabled=false \
--set prometheus.prometheusSpec.serviceMonitorSelectorNilUsesHelmValues=false
5. Install Ingress Controller
Install the NGINX Ingress Controller using Helm:
helm repo add ingress-nginx https://kubernetes.github.io/ingress-nginx
helm repo update
helm upgrade --install nginx-ingress ingress-nginx/ingress-nginx \
--namespace nginx \
--set controller.metrics.enabled=true \
--set controller.metrics.serviceMonitor.enabled=true \
--create-namespace
This will deploy a nginx ingress controller in the ingress-nginx namespace.
Install the Istio Ingress Controller using Helm:
# Download the latest Istio release from the official Istio website.
curl -L https://istio.io/downloadIstio | sh -
# Move it to home directory
mv istio-x.xx.x ~/.istioctl
export PATH=$HOME/.istioctl/bin:$PATH
istioctl install --set profile=default -y
# Label the namespace where you want to deploy your application to enable Istio sidecar Injection
kubectl create namespace target
kubectl label namespace target istio-injection=enabled
# Create a gateway
kubectl apply -f ./playground/config/gateway.yaml
This will deploy a Istio ingress controller in the istio-system namespace.
6. Deploy KubeElasti Locally
We will be using playground/infra/elasti-demo-values.yaml for the helm installation. Configure the image uri according to the requirement. Post that follow below steps from the project home directory:
kubectl create namespace elasti
helm upgrade --install elasti ./charts/elasti -n elasti -f ./playground/infra/elasti-demo-values.yaml
If you want to enable monitoring, please make enableMonitoring true in the values file.
7. Deploy a demo service
Run a demo application in your cluster. We will use a sample httpbin service to demonstrate how to configure a service to handle its traffic via elasti.
kubectl create namespace target
kubectl apply -f ./playground/config/demo-application.yaml -n target
Add virtual service if you are using istio.
# ONLY IF YOU ARE USING ISTIO
# Create a Virtual Service to expose the demo service
kubectl apply -f ./playground/config/demo-virtualService.yaml
This will deploy a httpbin service in the target namespace.
8. Create ElastiService Resource
Using the ElastiService Definition, create a manifest file for your service and apply it. For demo, we use the below manifest.
9. Test the service
9.1 Scale down the service
9.2 Send request to the service while target is scaled down
9.3 Portforward Ingress
kubectl port-forward svc/nginx-ingress-controller 8080:80 -n ingress-nginx
# or
kubectl port-forward -n istio-system svc/istio-ingressgateway 8080:80
You should see the target service pod getting scaled up and response from the new pod.
10. Debug tips
10.1 Watch logs
kubectl logs -n elasti deployments/elasti-operator-controller-manager -f
kubectl logs -n elasti deployments/elasti-resolver -f
kubectl logs -n target deployments/httpbin -f
kubectl logs -n istio-system deployments/istiod -f
10. Delete KubeElasti
11. Redeploy KubeElasti
In case you want to redeploy KubeElasti, with your latest changes, you can use the below command:
11.1 Delete the ElastiService
11.2 Delete the KubeElasti
11.3 Remove old images
docker rmi localhost:5001/elasti-resolver:v1alpha1
docker rmi localhost:5001/elasti-operator:v1alpha1
Post this, repeat steps 6 and 8, to redeploy KubeElasti.