Kubernetes operator for setting IPVS weights on Kubernetes ClusterIP services.
The operator provides a new Kubernetes resource called a WeightedService.
This operator is in very early alpha and should be used with care.
Follow the IPVS guide to configure your Kubernetes cluster to use IPVS instead of iptables.
To install the operator, simply apply the manifest:
kubectl apply -f https://raw.githubusercontent.com/justinbarrick/ipvs-operator/master/deploy/operator.yaml
This will install the IPVS operator as a DaemonSet on all of your nodes.
You can use a WeightedService to apply IPVS load balancing weights to pods matching certain labels.
A WeightService can enable canary deployments by setting different weights for your canary and production deployments. See the IPVS weighted round-robin documentation for more information. If a scheduler is not set, it defaults to "wrr".
For example, to send 10% of traffic to your canary deployment:
apiVersion: codesink.net/v1alpha1
kind: WeightedService
metadata:
name: example
spec:
selector:
app: nginx
ports:
- protocol: TCP
port: 80
targetPort: www
scheduler: wlc
weights:
- weight: 10
selector:
env: prod
- weight: 1
selector:
env: canary
The WeightedService will create a Service matching the provided ServiceSpec and assign weights to pods that match the specified labels.
See test/example.yaml for a full example.
Note that the service weights will not apply for anything that routes directly to endpoint IPs (e.g., some ingress controllers by default), but will work for the service IP. For example, if you're using the nginx ingress controller set the service-upstream annotation:
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: "canary-demo.local"
annotations:
nginx.ingress.kubernetes.io/service-upstream: "true"
spec:
rules:
- host: canary-demo.local
http:
paths:
- path: /
backend:
serviceName: example
servicePort: 80