Multinetwork statefulsets

README.md

Multicluster statefulset

alpha.yaml: install in cluster "alpha" beta.yaml: install in cluster "beta"

Results:

Same network

• echo-alpha.default: sort of works, but load balancing is broken (istio/istio#31064)
• echo-alpha-0.default: works
• echo-alpha-0.echo-alpha.default: works
• POD_IP: works

Cross network

• echo-alpha.default: broken. Routing is passthrough, which doesn't go through gateway
• echo-alpha-0.default: works
• echo-alpha-0.echo-alpha.default: works
• POD_IP: broken. For http we hit passthrough cluster (host header routing). For TCP, we match the echo-alpha.default which doesn't work per above

alpha.yaml

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: echo-alpha
spec:
  selector:
    matchLabels:
      app: echo-alpha
  serviceName: echo-alpha
  replicas: 2
  template:
    metadata:
      labels:
        app: echo-alpha
    spec:
      containers:
      - name: echo-alpha
        image: gcr.io/istio-testing/app:latest
        args:
        - --tcp=9090
        - --port=80
        - --port=443
        - --tls=443
        - --crt=/cert.crt
        - --key=/cert.key
---
apiVersion: v1
kind: Service
metadata:
  name: echo-alpha
spec:
  selector:
    app: echo-alpha
  clusterIP: None
  ports:
  - name: http
    port: 80
  - name: https
    port: 443
  - name: tcp
    port: 9090
---
# Option 1: Service
# Note: we get a different hostname here!
apiVersion: v1
kind: Service
metadata:
  name: echo-alpha-0
spec:
  selector:
    statefulset.kubernetes.io/pod-name: echo-alpha-0
  # clusterIP: None # In single network, probably best to use headless
  # We will fix dns resolution to not need this service for single network though
  ports:
  - name: http
    port: 80
  - name: https
    port: 443
  - name: tcp
    port: 9090
---
# Option 2: ServiceEntry
apiVersion: networking.istio.io/v1beta1
kind: ServiceEntry
metadata:
  name: echo-alpha-0
spec:
  addresses:
  - 240.0.0.11
  workloadSelector:
    labels:
      statefulset.kubernetes.io/pod-name: echo-alpha-0
  hosts:
  - echo-alpha-0.echo-alpha.default.svc.cluster.local
  location: MESH_INTERNAL
  ports:
  - name: http
    number: 80
    protocol: HTTP
  - name: https
    number: 443
    protocol: HTTPS
  - name: tcp
    number: 9090
    protocol: TCP
  resolution: STATIC
---

beta.yaml

# Option 1: Service
# Note: we get a different hostname here!
apiVersion: v1
kind: Service
metadata:
  name: echo-alpha-0
spec:
  selector:
    statefulset.kubernetes.io/pod-name: echo-alpha-0
  # clusterIP: None # In single network, probably best to use headless
  # We will fix dns resolution to not need this service for single network though
  ports:
  - name: http
    port: 80
  - name: https
    port: 443
  - name: tcp
    port: 9090
---
# Option 2: ServiceEntry
apiVersion: networking.istio.io/v1beta1
kind: ServiceEntry
metadata:
  name: echo-alpha-0
spec:
  addresses:
  - 240.0.0.11
  workloadSelector:
    labels:
      statefulset.kubernetes.io/pod-name: echo-alpha-0
  hosts:
  - echo-alpha-0.echo-alpha.default.svc.cluster.local
  location: MESH_INTERNAL
  ports:
  - name: http
    number: 80
    protocol: HTTP
  - name: https
    number: 443
    protocol: HTTPS
  - name: tcp
    number: 9090
    protocol: TCP
  resolution: STATIC
---