Traefik 企業(yè)實(shí)戰(zhàn)：TraefikService篇

作者：Jack 2023-09-05 07:24:33

灰度發(fā)布也稱為金絲雀發(fā)布，讓一部分即將上線的服務(wù)發(fā)布到線上，觀察是否達(dá)到上線要求，主要通過加權(quán)輪詢的方式實(shí)現(xiàn)。創(chuàng)建 traefikService 和 inressRoute 資源，實(shí)現(xiàn) wrr 加權(quán)輪詢 app-traefikService-ingressroute-wrr.yaml。

簡(jiǎn)介

traefik 的路由規(guī)則就可以實(shí)現(xiàn) 4 層和 7 層的基本負(fù)載均衡操作，使用 IngressRoute IngressRouteTCP IngressRouteUDP 資源即可。但是如果想要實(shí)現(xiàn) 加權(quán)輪詢、流量復(fù)制等高級(jí)操作，traefik抽象出了一個(gè) TraefikService 資源。此時(shí)整體流量走向?yàn)椋和獠苛髁肯韧ㄟ^ entryPoints 端口進(jìn)入 traefik，然后由 IngressRoute/IngressRouteTCP/IngressRouteUDP 匹配后進(jìn)入 TraefikService，在 TraefikService 這一層實(shí)現(xiàn)加權(quán)輪循和流量復(fù)制，最后將請(qǐng)求轉(zhuǎn)發(fā)至kubernetes的service。

創(chuàng)建Demo應(yīng)用

app-v1.yaml：

apiVersion: apps/v1
kind: Deployment
metadata:
  name: app-v1
spec:
  replicas: 1
  selector:
    matchLabels:
      app: app-v1
  template:
    metadata:
      labels:
        app: app-v1
    spec:
      containers:
        - name: app-v1
          image: nginx:latest
          lifecycle:
            postStart:
              exec:
                command:  ["/bin/sh", "-c", "echo Hello app-v1 > /usr/share/nginx/html/index.html"]
          ports:
            - containerPort: 80
          resources:
            requests:
              cpu: 100m
              memory: 128Mi
            limits:
              cpu: 200m
              memory: 256Mi
    
---
apiVersion: v1
kind: Service
metadata:
  name: app-v1
spec:
  selector:
    app: app-v1
  ports:
    - name: http
      port: 80
      targetPort: 80
  type: ClusterIP

app-v2.yaml：

apiVersion: apps/v1
kind: Deployment
metadata:
  name: app-v2
spec:
  replicas: 1
  selector:
    matchLabels:
      app: app-v2
  template:
    metadata:
      labels:
        app: app-v2
    spec:
      containers:
        - name: app-v2
          image: nginx:latest
          lifecycle:
            postStart:
              exec:
                command:  ["/bin/sh", "-c", "echo Hello app-v2 > /usr/share/nginx/html/index.html"]
          ports:
            - containerPort: 80
          resources:
            requests:
              cpu: 100m
              memory: 128Mi
            limits:
              cpu: 200m
              memory: 256Mi
    
---
apiVersion: v1
kind: Service
metadata:
  name: app-v2
spec:
  selector:
    app: app-v2
  ports:
    - name: http
      port: 80
      targetPort: 80
  type: ClusterIP

部署

[root@localhost traefik]# kubectl apply -f app-v1.yaml
deployment.apps/app-v1 created
service/app-v1 created
[root@localhost traefik]# kubectl apply -f app-v2.yaml 
deployment.apps/app-v2 created
service/app-v2 created
 
 
 
 
[root@localhost traefik]# kubectl get pod,svc                      
NAME                          READY   STATUS    RESTARTS   AGE
pod/app-v1-579dbbb754-nwtzw   1/1     Running   0          2m23s
pod/app-v2-7f7844f7b9-grsdk   1/1     Running   0          2m19s
 
NAME                 TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)   AGE
service/app-v1       ClusterIP   10.100.10.94     <none>        80/TCP    2m23s
service/app-v2       ClusterIP   10.104.145.150   <none>        80/TCP    2m18s

灰度發(fā)布(加權(quán)輪詢)

apiVersion: traefik.containo.us/v1alpha1
kind: IngressRoute
metadata:
  name: app-ingressroute-wrr
  namespace: default
spec:
  entryPoints:
    - web
  routes:
  - match: Host(`traefikservice-wrr.kubesre.lc`)
    kind: Rule
    services:
    - name: wrr
      namespace: default
      kind: TraefikService
---
apiVersion: traefik.containo.us/v1alpha1
kind: TraefikService
metadata:
  name: wrr
  namespace: default
spec:
  weighted:
    services:
      - name: app-v1 
        port: 80
        weight: 1          # 定義權(quán)重
        kind: Service      # 可選，默認(rèn)就是 Service
      - name: app-v2
        port: 80    
        weight: 2

部署

[root@localhost traefik]# kubectl apply -f app-traefikService-ingressroute-wrr.yaml
ingressroute.traefik.containo.us/app-ingressroute-wrr created
traefikservice.traefik.containo.us/wrr created  
 
[root@localhost traefik]# kubectl get ingressroute
NAME                   AGE
app-ingressroute-wrr   6s
 [root@localhost traefik]# kubectl get TraefikService
NAME   AGE
wrr    3m42s

添加本地hosts解析

192.168.36.139 traefikservice-wrr.kubesre.lcc

測(cè)試結(jié)果如下：

[root@localhost traefik]# for i in {1..9}; do curl http://traefikservice-wrr.kubesre.lc && sleep 1; done             
Hello app-v1
Hello app-v2
Hello app-v2
Hello app-v1
Hello app-v2
Hello app-v2
Hello app-v1
Hello app-v2
Hello app-v2

會(huì)話保持(粘性會(huì)話)

當(dāng)我們使用 traefik 的負(fù)載均衡時(shí)，默認(rèn)情況下輪循多個(gè) k8s 的 service 服務(wù)，如果用戶對(duì)同一內(nèi)容的多次請(qǐng)求，可能被轉(zhuǎn)發(fā)到了不同的后端服務(wù)器。假設(shè)用戶發(fā)出請(qǐng)求被分配至服務(wù)器 A，保存了一些信息在 session 中，該用戶再次發(fā)送請(qǐng)求被分配到服務(wù)器 B，要用之前保存的信息，若服務(wù)器 A 和 B 之間沒有 session 粘滯，那么服務(wù)器 B 就拿不到之前的信息，這樣會(huì)導(dǎo)致一些問題。traefik 同樣也支持粘性會(huì)話，可以讓用戶在一次會(huì)話周期內(nèi)的所有請(qǐng)求始終轉(zhuǎn)發(fā)到一臺(tái)特定的后端服務(wù)器上。創(chuàng)建 traefikervie 和 ingressRoute，實(shí)現(xiàn)基于 cookie 的會(huì)話保持 app-traefikService-ingressroute-cokie.yaml：

apiVersion: traefik.containo.us/v1alpha1
kind: IngressRoute
metadata:
  name: app-ingressroute-cokie
  namespace: default
spec:
  entryPoints:
    - web
  routes:
  - match: Host(`traefikservice-cokie.kubesre.lc`)
    kind: Rule
    services:
    - name: cokie
      namespace: default
      kind: TraefikService
---
apiVersion: traefik.containo.us/v1alpha1
kind: TraefikService
metadata:
  name: cokie
  namespace: default
spec:
  weighted:
    services:
      - name: app-v1
        port: 80
        weight: 1          # 定義權(quán)重
      - name: app-v2
        port: 80
        weight: 2
    sticky:                 # 開啟粘性會(huì)話
      cookie:               # 基于cookie區(qū)分客戶端     
        name: cookie   # 指定客戶端請(qǐng)求時(shí)，包含的cookie名稱

部署

[root@localhost traefik]# kubectl apply -f  app-traefikService-ingressroute-cokie.yaml   
ingressroute.traefik.containo.us/app-ingressroute-cokie created
traefikservice.traefik.containo.us/cokie created
 
[root@localhost traefik]# kubectl get ingressroute
NAME                     AGE
app-ingressroute-cokie   5s
[root@localhost traefik]# kubectl get TraefikService
NAME    AGE
cokie   8s

添加本地hosts解析

192.168.36.139 traefikservice-cokie.kubesre.lcc

客戶端訪問測(cè)試，攜帶 cookie

[root@localhost traefik]# for i in {1..5}; do curl -b "cookie=default-app-v1-80" http://traefikservice-cokie.kubesre.lc/; done
Hello app-v1
Hello app-v1
Hello app-v1
Hello app-v1
Hello app-v1
[root@localhost traefik]# for i in {1..5}; do curl -b "cookie=default-app-v2-80" http://traefikservice-cokie.kubesre.lc/; done
Hello app-v2
Hello app-v2
Hello app-v2
Hello app-v2
Hello app-v2

流量復(fù)制

所謂的流量復(fù)制，也稱為鏡像服務(wù)是指將請(qǐng)求的流量按規(guī)則復(fù)制一份發(fā)送給其它服務(wù)，并且會(huì)忽略這部分請(qǐng)求的響應(yīng)，這個(gè)功能在做一些壓測(cè)或者問題復(fù)現(xiàn)的時(shí)候很有用。創(chuàng)建 traefikService 和 ingressRoute app-traefikService-ingressroute-copy.yaml：

apiVersion: traefik.containo.us/v1alpha1
kind: IngressRoute
metadata:
  name: app-ingressroute-copy
  namespace: default
spec:
  entryPoints:
    - web
  routes:
  - match: Host(`traefikservice-copy.kubesre.lc`)
    kind: Rule
    services:
    - name: copy
      namespace: default
      kind: TraefikService
---
apiVersion: traefik.containo.us/v1alpha1
kind: TraefikService
metadata:
  name: copy
  namespace: default
spec:
  mirroring:
    name: app-v1       # 發(fā)送 100% 的請(qǐng)求到 app-v1
    port: 80
    mirrors:
      - name: app-v2   # 然后復(fù)制 10% 的請(qǐng)求到 app-v2
        port: 80
        percent: 10

部署

[root@localhost traefik]# kubectl apply -f app-traefikService-ingressroute-copy.yaml
ingressroute.traefik.containo.us/app-ingressroute-copy created
traefikservice.traefik.containo.us/copy created
 
[root@localhost traefik]# kubectl get ingressroute
NAME                     AGE
app-ingressroute-copy    7s
[root@localhost traefik]# kubectl get TraefikService
NAME    AGE
copy    13s

添加本地hosts解析

192.168.36.139 traefikservice-copy.kubesre.lc

測(cè)試結(jié)果如下：只能看到 app-v1的返回信息，

[root@localhost traefik]#  for i in {1..9}; do curl http://traefikservice-copy.kubesre.lc && sleep 1; done   
Hello app-v1
Hello app-v1
Hello app-v1
Hello app-v1
Hello app-v1
Hello app-v1
Hello app-v1
Hello app-v1
Hello app-v1

查看app-v2的pod日志，發(fā)現(xiàn)會(huì)有10%的流量請(qǐng)求進(jìn)來

[root@localhost traefik]# kubectl logs -f app-v2-7f7844f7b9-grsdk
...
10.244.0.5 - - [23/Aug/2023:02:54:36 +0000] "GET / HTTP/1.1" 200 13 "-" "curl/7.29.0" "10.244.0.1"

責(zé)任編輯：武曉燕來源：云原生運(yùn)維圈

Traefik 加權(quán)輪詢