基于deployment实现金丝雀发布

l333308
61 阅读2分钟

金丝雀、蓝绿升级

金丝雀：先在1台或少数机器升级，验证无误后再升级其他。优点为影响面小且可控，缺点是需要额外实现自动更新。

蓝绿：2组机器，蓝代表当前v1版本，绿为已升级的v2版本。通过LB将流量导到V2完成升级。优点是切换迅速，缺点是会影响全部用户。

情景描述

以下是一个，利用deployment下的ReplicaSet、Pod特性，对于金丝雀发布的实现。

思路：

  • 10个replicas，版本为v1
  • 部署一个v2版本的replica（占比为10%）
  • 等待一段时间，确保v2版本正常服务
  • 部署10个v2版本的副本数
  • 等待，直至所有pod实例状态为Ready
  • 停止所有v1的replica

v1、v2配置文件

app-v1.yaml

apiVersion: v1
kind: Service
metadata:
  name: my-app
  labels:
    app: my-app
spec:
  type: NodePort
  ports:
  - name: http
    port: 80
    targetPort: http
  selector:
    app: my-app
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-app-v1
  labels:
    app: my-app
spec:
  replicas: 10
  selector:
    matchLabels:
      app: my-app
      version: v1.0.0
  template:
    metadata:
      labels:
        app: my-app
        version: v1.0.0
      annotations:
        prometheus.io/scrape: "true"
        prometheus.io/port: "9101"
    spec:
      containers:
      - name: my-app
        image: containersol/k8s-deployment-strategies
        ports:
        - name: http
          containerPort: 8080
        - name: probe
          containerPort: 8086
        env:
        - name: VERSION
          value: v1.0.0
        livenessProbe:
          httpGet:
            path: /live
            port: probe
          initialDelaySeconds: 5
          periodSeconds: 5
        readinessProbe:
          httpGet:
            path: /ready
            port: probe
          periodSeconds: 5

app-v2.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-app-v2
  labels:
    app: my-app
spec:
  replicas: 1
  selector:
    matchLabels:
      app: my-app
      version: v2.0.0
  template:
    metadata:
      labels:
        app: my-app
        version: v2.0.0
      annotations:
        prometheus.io/scrape: "true"
        prometheus.io/port: "9101"
    spec:
      containers:
      - name: my-app
        image: containersol/k8s-deployment-strategies
        ports:
        - name: http
          containerPort: 8080
        - name: probe
          containerPort: 8086
        env:
        - name: VERSION
          value: v2.0.0
        livenessProbe:
          httpGet:
            path: /live
            port: probe
          initialDelaySeconds: 5
          periodSeconds: 5
        readinessProbe:
          httpGet:
            path: /ready
            port: probe
          periodSeconds: 5

开始表演

# 部署v1的deploy
[root@master k8s]# k apply -f app-v1.yaml 
service/my-app created
deployment.apps/my-app-v1 created

# 验证deploy是否部署成功
[root@master k8s]# curl 10.101.252.35:80
Host: my-app-v1-599bdf7545-qjdvw, Version: v1.0.0

# 新开窗口 查看pod数量变化
kubectl get po

# 部署v2 1个副本
[root@master k8s]# k apply -f app-v2.yaml
deployment.apps/my-app-v2 created

# 并将v1副本scale为9个 此时不同版本的副本为9+1
[root@master k8s]# kubectl scale --replicas=9 deploy my-app-v1
deployment.apps/my-app-v1 scaled

# 模拟业务请求
# 此处v1：v2不一定9：1，LB策略问题，不深究
[root@master k8s]# service=10.101.252.35:80
[root@master k8s]# while sleep 0.1; do curl "$service"; done
Host: my-app-v1-599bdf7545-cdjq9, Version: v1.0.0
Host: my-app-v1-599bdf7545-p57x9, Version: v1.0.0
Host: my-app-v1-599bdf7545-x9p97, Version: v1.0.0
Host: my-app-v1-599bdf7545-sr2cn, Version: v1.0.0
Host: my-app-v1-599bdf7545-cdjq9, Version: v1.0.0
Host: my-app-v2-7cdf7685d9-gzb42, Version: v2.0.0
Host: my-app-v1-599bdf7545-cdjq9, Version: v1.0.0
Host: my-app-v2-7cdf7685d9-gzb42, Version: v2.0.0
...

# 此时可以认为 v2版本服务正常 将其scale到10个副本
[root@master k8s]# kubectl scale --replicas=10 deploy my-app-v2
deployment.apps/my-app-v2 scaled

# 等v2 scale完毕 将v1的deploy删除
[root@master k8s]# kubectl delete deploy my-app-v1
deployment.apps "my-app-v1" deleted

# 重新模拟请求 回显符合期望
[root@master k8s]# while sleep 0.1; do curl "$service"; done
Host: my-app-v2-7cdf7685d9-nnr6d, Version: v2.0.0
Host: my-app-v2-7cdf7685d9-gzb42, Version: v2.0.0
Host: my-app-v2-7cdf7685d9-q75cg, Version: v2.0.0
Host: my-app-v2-7cdf7685d9-df94h, Version: v2.0.0
Host: my-app-v2-7cdf7685d9-df94h, Version: v2.0.0
...

# 清理现场
$ kubectl delete all -l app=my-app

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