GoZero is a reverse-proxy that can be deployed on Kubernetes. It can route HTTP/1.1, HTTP/2 (GRPC) requests to different services. And it can provide a way to scale services from zero to desired number of replicas and vice versa by relying on KEDA.
There are two ways to install GoZero:
- Using the
manifestsdirectory, which contains the Kubernetes manifests for GoZero.
kubectl apply -f manifests/manifests.yaml- Using the
chartdirectory, which contains the Helm chart for GoZero.
helm install gozero ./chart/gozeroWe need to have two Kubernetes resources to use GoZero:
VirtualServiceto route the request to GoZero, then GoZero will route the request to the target service.
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: app
namespace: app-a
spec:
hosts:
- app-app-a.k8s.orb.local # The host of the request.
gateways:
- istio-system/ingress # The gateway to the request.
http:
- headers:
request:
add:
X-Gozero-Target-Port: "3000" # The port of the target service.
X-Gozero-Target-Host: "app.app-a.svc.cluster.local" # The host of the target service.
X-Gozero-Target-Retries: "10" # The number of retries to the target service. (optional)
X-Gozero-Target-Backoff: "100ms" # The backoff time to the target service. (optional)
route:
- destination:
host: gozero.gozero.svc.cluster.local # The GoZero service.
port:
number: 8443 # The proxy port of the GoZero service.
retries:
attempts: 1
perTryTimeout: 300s # Set it higher than the time that the target service takes to be ready.- KEDA
ScaledObjectto scale the target service.
apiVersion: keda.sh/v1alpha1
kind: ScaledObject
metadata:
name: app-a
namespace: app-a
spec:
pollingInterval: 10 # The interval to check the metrics.
cooldownPeriod: 30 # The cooldown period to scale down the target service.
minReplicaCount: 0 # The minimum number of replicas of the target service.
maxReplicaCount: 2 # The maximum number of replicas of the target service.
scaleTargetRef:
name: app # The name of the target service.
apiVersion: apps/v1
kind: Deployment
triggers:
- type: metrics-api
metadata:
targetValue: "1" # The target value to scale the target service, which will be compared with value from the metrics which is 10 by default.
format: "json"
activationTargetValue: "1" # When should enable scale up from zero. The target value to activate the scaling, which will be compared with value from the metrics which is 10 by default.
url: "http://gozero.gozero.svc.cluster.local:9090/metrics/app-app-a-svc-cluster-local" # Replace the . with - in the host of the request.
valueLocation: "value"
For more information about the ScaledObject, please refer to the KEDA ScaledObject Spec.
You can find the design of GoZero in Design page.
You can find the FAQ of GoZero in FAQ page.