K8S - 实现statefulset 有状态service的灰度发布

什么是灰度发布 Canary Release

参考
理解 什么是 滚动更新,蓝绿部署,灰度发布 以及它们的区别

配置partition in updateStrategy/rollingUpdate

这次我为修改了 statefulset 的1个yaml file

statefulsets/stateful-nginx-without-pvc.yaml:

yaml 复制代码
---
apiVersion: v1 # api version
kind: Service # type of this resource e.g. Pod/Deployment ..
metadata:
  name: nginx-stateful-service # name of the service
  labels:
    app: nginx-stateful-service
spec:
  ports: 
  - port: 80 # port of the service, used to access the service
    name: web-port
  clusterIP: None # the service is not exposed outside the cluster
  selector: # label of the Pod that the Service is selecting
    app: nginx-stateful # only service selector could skip the matchLabels:
---


apiVersion: apps/v1
kind: StatefulSet # it's for a stateful application, it's a controller
metadata:
  name: nginx-statefulset # name of the statefulset
  labels:
    app: nginx-stateful
spec: # detail description
  serviceName: "nginx-stateful-service" # name of the service that used to manange the dns,  
                                         # must be the same as the service name defined above
  replicas: 3 # desired replica count
  selector: # label of the Pod that the StatefulSet is managing
    matchLabels:
      app: nginx-stateful
  template: # Pod template
    metadata:
      labels:
        app: nginx-stateful
    spec:
      containers:
      - name: nginx-containe
        image: nginx:1.25.4 # image of the container
        ports: # the ports of the container and they will be exposed
        - containerPort: 80 # the port used by the container service
          name: web-port
  updateStrategy:
    rollingUpdate:
      partition: 2
    type: RollingUpdate

关键是最后1个block

yaml 复制代码
  updateStrategy:
    rollingUpdate:
      partition: 2
    type: RollingUpdate

rollingUpdate 很容易理解, 关键是partition 的值

这个值表示在image 版本更新后, 只会更新 pod-index 中index >= partition 的POD, 其他POD保持先版本, 这就能同时让两个版本存在一段时间, 实现灰度发布

一个例子

首先我们先apply 上面的yaml
bash 复制代码
[gateman@manjaro-x13 statefulsets]$ kubectl apply -f stateful-nginx-without-pvc.yaml 
service/nginx-stateful-service unchanged
statefulset.apps/nginx-statefulset created
检查pods , 3个pod 起来了分别是0, 1, 2
bash 复制代码
[gateman@manjaro-x13 statefulsets]$ kubectl get pods -o wide
NAME                  READY   STATUS    RESTARTS   AGE   IP             NODE        NOMINATED NODE   READINESS GATES
nginx-statefulset-0   1/1     Running   0          12m   10.244.2.120   k8s-node0   <none>           <none>
nginx-statefulset-1   1/1     Running   0          12m   10.244.1.59    k8s-node1   <none>           <none>
nginx-statefulset-2   1/1     Running   0          12m   10.244.3.69    k8s-node3   <none>           <none>
为了更好的present, 我们把pods数量scale 到5个
bash 复制代码
[gateman@manjaro-x13 statefulsets]$ kubectl scale statefulset nginx-statefulset --replicas=5
statefulset.apps/nginx-statefulset scaled
[gateman@manjaro-x13 statefulsets]$ kubectl get pods -o wide
NAME                  READY   STATUS    RESTARTS   AGE   IP             NODE        NOMINATED NODE   READINESS GATES
nginx-statefulset-0   1/1     Running   0          13m   10.244.2.120   k8s-node0   <none>           <none>
nginx-statefulset-1   1/1     Running   0          13m   10.244.1.59    k8s-node1   <none>           <none>
nginx-statefulset-2   1/1     Running   0          13m   10.244.3.69    k8s-node3   <none>           <none>
nginx-statefulset-3   1/1     Running   0          13s   10.244.2.121   k8s-node0   <none>           <none>
nginx-statefulset-4   1/1     Running   0          12s   10.244.3.70    k8s-node3   <none>           <none>

这时5个pod 起来了

查看每个pod的image 版本
bash 复制代码
[gateman@manjaro-x13 statefulsets]$ kubectl get pods -o=jsonpath='{range .items[*]}{.metadata.name}{"\t"}{.spec.containers[*].image}{"\n"}{end}'
nginx-statefulset-0	nginx:1.25.4
nginx-statefulset-1	nginx:1.25.4
nginx-statefulset-2	nginx:1.25.4
nginx-statefulset-3	nginx:1.25.4
nginx-statefulset-4	nginx:1.25.4
这时我们更新image 版本从 1.25.4 更新到1.26.1
bash 复制代码
[gateman@manjaro-x13 statefulsets]$ kubectl set image statefulset/nginx-statefulset nginx-container=nginx:1.26.1
statefulset.apps/nginx-statefulset image updated
再次检查 每个pod 的image version
bash 复制代码
nginx-statefulset-0	nginx:1.25.4
nginx-statefulset-1	nginx:1.25.4
nginx-statefulset-2	nginx:1.26.1
nginx-statefulset-3	nginx:1.26.1
nginx-statefulset-4	nginx:1.26.1

可以见到只有pod 2 3 和4 更新了, 0, 1 还是旧版本

下一步, 把新版本应到pod 1 和 pod 0

也很简单, 只需要更改partition 的值就行

yaml 复制代码
---
apiVersion: v1 # api version
kind: Service # type of this resource e.g. Pod/Deployment ..
metadata:
  name: nginx-stateful-service # name of the service
  labels:
    app: nginx-stateful-service
spec:
  ports: 
  - port: 80 # port of the service, used to access the service
    name: web-port
  clusterIP: None # the service is not exposed outside the cluster
  selector: # label of the Pod that the Service is selecting
    app: nginx-stateful # only service selector could skip the matchLabels:
---


apiVersion: apps/v1
kind: StatefulSet # it's for a stateful application, it's a controller
metadata:
  name: nginx-statefulset # name of the statefulset
  labels:
    app: nginx-stateful
spec: # detail description
  serviceName: "nginx-stateful-service" # name of the service that used to manange the dns,  
                                         # must be the same as the service name defined above
  replicas: 5 # desired replica count
  selector: # label of the Pod that the StatefulSet is managing
    matchLabels:
      app: nginx-stateful
  template: # Pod template
    metadata:
      labels:
        app: nginx-stateful
    spec:
      containers:
      - name: nginx-container
        image: nginx:1.26.1 # image of the container
        ports: # the ports of the container and they will be exposed
        - containerPort: 80 # the port used by the container service
          name: web-port
  updateStrategy:
    rollingUpdate:
      partition: 1
    type: RollingUpdate

记得修改3个地方, 1是

replicas: 5 改成当前的数量

image: nginx:1.26.1 要改成新的版本

partition: 1 改成1 就是意思把pod 1 也部署新版本

bash 复制代码
[gateman@manjaro-x13 statefulsets]$ kubectl replace -f stateful-nginx-without-pvc.yaml 
service/nginx-stateful-service replaced
statefulset.apps/nginx-statefulset replaced
bash= 复制代码
[gateman@manjaro-x13 statefulsets]$ kubectl get pods -o=jsonpath='{range .items[*]}{.metadata.name}{"\t"}{.spec.containers[*].image}{"\n"}{end}'
nginx-statefulset-0	nginx:1.25.4
nginx-statefulset-1	nginx:1.26.1
nginx-statefulset-2	nginx:1.26.1
nginx-statefulset-3	nginx:1.26.1
nginx-statefulset-4	nginx:1.26.1

这时只有pod0 还是旧版本

如何 把pod0 也同步?

方法1是用上面的方法重新更新partition 的值为0

方法2使用 kubectl patch 修改

kubectl patch statefulset nginx-statefulset --type='json' -p='[{"op": "replace", "path": "/spec/updateStrategy/rollingUpdate/partition", "value": 0}]'

bash 复制代码
[gateman@manjaro-x13 statefulsets]$ kubectl get pods -o=jsonpath='{range .items[*]}{.metadata.name}{"\t"}{.spec.containers[*].image}{"\n"}{end}'
nginx-statefulset-0	nginx:1.26.1
nginx-statefulset-1	nginx:1.26.1
nginx-statefulset-2	nginx:1.26.1
nginx-statefulset-3	nginx:1.26.1
nginx-statefulset-4	nginx:1.26.1

Deployment 的灰度发布

如果是无状态service 的deployment , 可以用这种方法灰度发布吗?

不行

因为 deployment 的pods 的后续不是1个index 数字, 无序的, 所以无法去比较 pod 的index 和 partition的值

强行写上yaml 就会有如下错误:

bash 复制代码
[gateman@manjaro-x13 bq-api-service]$ kubectl apply -f bq-api-service-test.yaml 
error: error validating "bq-api-service-test.yaml": error validating data: ValidationError(Deployment.spec.strategy.rollingUpdate): unknown field "partition" in io.k8s.api.apps.v1.RollingUpdateDeployment; if you choose to ignore these errors, turn validation off with --validate=false

但是灰度发布只是1个思想, 实现的方法有很多种

deployment的灰度发布在k8s 是可行的, 例如简单粗暴地用多个deployment 去cover 不同的instance. 具体方法不在此讨论

相关推荐
终端行者15 小时前
k8s之Ingress服务接入控制器
云原生·容器·kubernetes
学Linux的语莫20 小时前
k8s的nodeport和ingress
网络·rpc·kubernetes
aashuii1 天前
k8s通过NUMA亲和分配GPU和VF接口
云原生·容器·kubernetes
Most661 天前
kubesphere安装使用
kubernetes
Kentos(acoustic ver.)1 天前
云原生 —— K8s 容器编排系统
云原生·容器·kubernetes·云计算·k8s
哈里谢顿2 天前
Kubernetes 简介
kubernetes
__Smile°2 天前
k8s-MongoDB 副本集部署
云原生·容器·kubernetes
Jy_06222 天前
k8s 中的 deployment,statefulset,daemonset 控制器的区别
云原生·容器·kubernetes
果子⌂2 天前
Kubernetes 服务发布进阶
linux·运维·服务器·云原生·容器·kubernetes·云计算
Gold Steps.2 天前
K8s WebUI 选型:国外 Rancher vs 国内 KubeSphere vs 原生 Dashboard,从部署到使用心得谁更适合企业级场景?
云原生·容器·kubernetes