Master Canary Deployments with Kruise Rollout: Gateway API, StatefulSet & Pod Batch Labels

Introduction

Kruise Rollout is an open‑source progressive delivery framework from the OpenKruise community. It supports canary, blue‑green, and A/B testing releases, can drive traffic and instance gray‑scale, and can automate batch pauses based on Prometheus metrics. It works with common workloads such as Deployment, CloneSet, StatefulSet and the Advanced StatefulSet extension.

Canary Release with Gateway API

The Ingress API has limitations for complex networking scenarios, so the SIG‑NETWORK community introduced the Gateway API as a unified standard. Kruise Rollout can use a HTTPRoute to perform canary releases. The example below defines a route to an echoserver service and a Rollout that releases 20 % of traffic with a pause.

apiVersion: gateway.networking.k8s.io/v1alpha2
kind: HTTPRoute
metadata:
  name: echoserver
spec:
  hostnames:
  - test.app.domain
  rules:
  - backendRefs:
    - group: ""
      name: echoserver
      port: 80
---
apiVersion: rollouts.kruise.io/v1alpha1
kind: Rollout
spec:
  objectRef:
    ...
  strategy:
    canary:
      steps:
      - weight: 20
        pause: {}
      trafficRoutings:
      - service: echoserver
        gateway:
          httpRouteName: echoserver

Batch Release for StatefulSet and Advanced StatefulSet

Stateful applications can also use progressive delivery. By leveraging the native StatefulSet partition feature, Rollout can manage batch upgrades for both standard StatefulSet and Advanced StatefulSet.

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: echoserver
spec:
  replicas: 5
  template:
    spec:
      containers:
      - name: echoserver
        image: cilium/echoserver:latest
---
apiVersion: rollouts.kruise.io/v1alpha1
kind: Rollout
metadata:
  name: rollouts-demo
spec:
  objectRef:
    workloadRef:
      apiVersion: apps/v1
      kind: StatefulSet
      name: echoserver
  strategy:
    canary:
      steps:
      - replicas: 1
        pause: {}
      - replicas: 2
        pause: {duration: 60}
      - replicas: 2

Pod Batch Labeling Feature

Kruise Rollout adds the label apps.kruise.io/rollout-batch-id to Pods, where the value corresponds to the batch number (1, 2, 3 …). The rolloutID field, supplied by the platform or user, distinguishes different releases and prevents label collisions when using in‑place upgrades of CloneSet.

apiVersion: rollouts.kruise.io/v1alpha1
kind: Rollout
metadata:
  name: rollouts-demo
spec:
  ...
  # required
  rolloutID: v1

The rolloutID can be any unique string, for example webserver-20220728120533.

Integration with KubeVela

KubeVela, an OAM‑based cloud‑native application platform, integrates Kruise Rollout as a trait. Users can enable canary releases via a Helm chart by adding a kruise-rollout trait to an Application definition.

apiVersion: core.oam.dev/v1beta1
kind: Application
spec:
  components:
  - name: canary-demo
    type: webservice
    properties:
      image: barnett/canarydemo:v1
    traits:
    - type: kruise-rollout
      properties:
        canary:
          steps:
          - weight: 20
            trafficRoutings:
            - type: nginx

References

https://github.com/openkruise/rollouts

https://kubevela.io/

https://openkruise.io/