New to Voyager? Please start here.
Forward Traffic to StatefulSet
Forward Traffic to all Pods of a StatefulSet
There is the usual way of forwarding traffic to a Service matching a StatefulSet. Create a Service with the pods label selector as selector, and use the service name as Backend ServiceName.
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: http
namespace: default
spec:
serviceName: "nginx-set"
replicas: 2
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: gcr.io/google_containers/nginx-slim:0.8
ports:
- containerPort: 80
name: http
----
apiVersion: v1
kind: Service
metadata:
name: nginx-set
namespace: default
labels:
app: nginx
spec:
ports:
- port: 80
name: http
clusterIP: None
selector:
app: nginx
Create another service for StatefulSets pods with selector.
apiVersion: v1
kind: Service
metadata:
name: nginx-service
namespace: default
labels:
app: nginx
spec:
ports:
- port: 80
name: http
selector:
app: nginx
And Use the service in the ingress Backend service name, as:
backend:
service:
name: nginx-service
port:
number: 80
That will forward traffic to your StatefulSets Pods.
Forward Traffic to specific Pods of a StatefulSet
There is a way to send traffic to all or specific pod of a StatefulSet using voyager. You can set hostNames field in Backend, traffic will only forwarded to those pods.
For Example the above StatefulSet will create two pod.
web-0
web-1
Those are the host names.
Now Create a ingress that will only forward traffic to web-0
apiVersion: voyager.appscode.com/v1
kind: Ingress
metadata:
name: test-ingress
namespace: default
spec:
rules:
- host: appscode.example.com
http:
paths:
- path: '/testPath'
backend:
hostNames:
- web-0
service:
name: nginx-set #! There is no extra service. This
port:
number: 80 # is the Statefulset's Headless Service
Viola. Now all /testPath traffic will be sent to pod web-0 only. There is no extra service also.
The StatefulSet’s Headless Service is enough. By using all the hostNames You can forward traffic to all pods.