istio入门教程

广告 | kubernetes各版本离线安装包

安装

安装k8s 强势插播广告

三步安装,不多说

安装helm, 推荐生产环境用helm安装,可以调参
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release地址

如我使用的2.9.1版本

yum install -y socat # 这个不装会报错
[root@istiohost ~]# wget https://storage.googleapis.com/kubernetes-helm/helm-v2.9.1-linux-amd64.tar.gz
[root@istiohost ~]# tar zxvf helm-v2.9.1-linux-amd64.tar.gz
[root@istiohost ~]# cp linux-amd64/helm /usr/bin

先创建一个service account 把管理员权限给helm:

[root@istiohost ~]# cat helmserviceaccount.yaml
apiVersion: v1
kind: ServiceAccount
metadata:
  name: tiller
  namespace: kube-system
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: tiller-clusterrolebinding
subjects:
- kind: ServiceAccount
  name: tiller
  namespace: kube-system
roleRef:
  kind: ClusterRole
  name: cluster-admin
  apiGroup: ""
kubectl create -f  helmserviceaccount.yaml

安装helm 服务端 tiller :

helm init  --service-account tiller #  如果已安装更新加 --upgrade 参数
helm list #没任何返回表示成功
安装istio
curl -L https://git.io/getLatestIstio | sh -
cd istio-1.0.0/
export PATH=$PWD/bin:$PATH

helm 2.10.0以前的版本需要装一下CRD:

kubectl apply -f install/kubernetes/helm/istio/templates/crds.yaml
kubectl apply -f install/kubernetes/helm/istio/charts/certmanager/templates/crds.yaml

安装istio, 由于你没有LB所以用NodePort代替:

helm install install/kubernetes/helm/istio  --name istio --namespace istio-system --set gateways.istio-ingressgateway.type=NodePort --set gateways.istio-egressgateway.type=NodePort

安装成功:

[root@istiohost istio-1.0.0]# kubectl get pod -n istio-system
NAME                                        READY     STATUS    RESTARTS   AGE
istio-citadel-7d8f9748c5-ntqnp              1/1       Running   0          5m
istio-egressgateway-676c8546c5-2w4cq        1/1       Running   0          5m
istio-galley-5669f7c9b-mkxjg                1/1       Running   0          5m
istio-ingressgateway-5475685bbb-96mbr       1/1       Running   0          5m
istio-pilot-5795d6d695-gr4h4                2/2       Running   0          5m
istio-policy-7f945bf487-gkpxr               2/2       Running   0          5m
istio-sidecar-injector-d96cd9459-674pk      1/1       Running   0          5m
istio-statsd-prom-bridge-549d687fd9-6cbzs   1/1       Running   0          5m
istio-telemetry-6c587bdbc4-jndjn            2/2       Running   0          5m
prometheus-6ffc56584f-98mr9                 1/1       Running   0          5m
[root@istiohost istio-1.0.0]# kubectl get svc -n istio-system
NAME                       TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)                                                                                                     AGE
istio-citadel              ClusterIP   10.108.253.89    <none>        8060/TCP,9093/TCP                                                                                           5m
istio-egressgateway        NodePort    10.96.151.14     <none>        80:30830/TCP,443:30038/TCP                                                                                  5m
istio-galley               ClusterIP   10.102.83.130    <none>        443/TCP,9093/TCP                                                                                            5m
istio-ingressgateway       NodePort    10.99.194.13     <none>        80:31380/TCP,443:31390/TCP,31400:31400/TCP,15011:31577/TCP,8060:30037/TCP,15030:31855/TCP,15031:30775/TCP   5m
istio-pilot                ClusterIP   10.101.4.143     <none>        15010/TCP,15011/TCP,8080/TCP,9093/TCP                                                                       5m
istio-policy               ClusterIP   10.106.221.68    <none>        9091/TCP,15004/TCP,9093/TCP                                                                                 5m
istio-sidecar-injector     ClusterIP   10.100.5.170     <none>        443/TCP                                                                                                     5m
istio-statsd-prom-bridge   ClusterIP   10.107.28.242    <none>        9102/TCP,9125/UDP                                                                                           5m
istio-telemetry            ClusterIP   10.105.66.20     <none>        9091/TCP,15004/TCP,9093/TCP,42422/TCP                                                                       5m
prometheus                 ClusterIP   10.103.128.152   <none>        9090/TCP

使用教程

官网事例 Bookinfo Application

istio入门教程

  • productpage 调用details和reviews渲染页面
  • details包含书本信息
  • reviews 书本反馈,调用ratings服务
  • ratings 书本租借信息

reviews服务有三个版本:

  • V1 不请求ratings
  • V2 请求ratings,返回1到5个黑星
  • V3 请求ratings,返回1到5个红星

数据平面:
istio入门教程

安装应用:

kubectl apply -f <(istioctl kube-inject -f samples/bookinfo/platform/kube/bookinfo.yaml)

安装完成:

[root@istiohost istio-1.0.0]# kubectl get services
NAME          TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)    AGE
details       ClusterIP   10.104.66.31    <none>        9080/TCP   2m
kubernetes    ClusterIP   10.96.0.1       <none>        443/TCP    4h
productpage   ClusterIP   10.109.68.13    <none>        9080/TCP   2m
ratings       ClusterIP   10.99.55.110    <none>        9080/TCP   2m
reviews       ClusterIP   10.102.19.129   <none>        9080/TCP   2m
[root@istiohost istio-1.0.0]# kubectl get pods
NAME                              READY     STATUS    RESTARTS   AGE
details-v1-fc9649d9c-dpnlp        2/2       Running   0          2m
productpage-v1-58845c779c-7g8th   2/2       Running   0          2m
ratings-v1-6cc485c997-fb7nh       2/2       Running   0          2m
reviews-v1-76987687b7-x5n7z       2/2       Running   0          2m
reviews-v2-86749dcd5-xchzb        2/2       Running   0          2m
reviews-v3-7f4746b959-nthrq       2/2       Running   0          2m

创建一个gateway,这是为了集群外可以访问

kubectl apply -f samples/bookinfo/networking/bookinfo-gateway.yaml

浏览器访问url:
47.254.28.88是我的节点ip,使用nodeport模式

http://47.254.28.88:31380/productpage

连续点击三次,你会发现右边没星星-> 黑星星-> 红星星切换,对应三个版本的review,默认策略是轮询

创建destination rules, 配置路由访问规则,现在还是轮询

kubectl apply -f samples/bookinfo/networking/destination-rule-all.yaml

智能路由

请求路由 request routing

根据版本路由

把所有路由切换到v1版本

kubectl apply -f samples/bookinfo/networking/virtual-service-all-v1.yaml

这样执行完后,不管怎么刷页面,我们都看不到星星,因为v1版本没星

可以看到destination是这样的:

http:
  - route:
    - destination:
        host: details
        subset: v1

试想如此我们做版本切换将是何等简单

根据用户路由

kubectl apply -f samples/bookinfo/networking/virtual-service-reviews-test-v2.yaml

你会发现用jason用户登录就能看到黑星星,而其它方式看到的页面都是无星星

因为这个user走了v2版本,能不强大? 那当然还能根据header什么的做路由了,就不多说了

http:
  - match:
    - headers:
        end-user:
          exact: jason
    route:
    - destination:
        host: reviews
        subset: v2
  - route:
    - destination:
        host: reviews
        subset: v1

故障注入 Fault injection

kubectl apply -f samples/bookinfo/networking/virtual-service-all-v1.yaml
kubectl apply -f samples/bookinfo/networking/virtual-service-reviews-test-v2.yaml

假设代码里有个bug,用户jason, reviews:v2 访问ratings时会卡10s, 我们任然希望端到端的测试能正常走完

kubectl apply -f samples/bookinfo/networking/virtual-service-ratings-test-delay.yaml

注入错误让jason用户有个7s的延迟

hosts:
  - ratings
  http:
  - fault:
      delay:
        fixedDelay: 7s
        percent: 100
    match:
    - headers:
        end-user:
          exact: jason
    route:
    - destination:
        host: ratings
        subset: v1
  - route:
    - destination:
        host: ratings
        subset: v1

这时访问页面显然会出错,因为我们希望7s内能返回,这样我们就发现了一个延迟的bug

Error fetching product reviews!
Sorry, product reviews are currently unavailable for this book.

所以我们就可能通过故障注入去发现这些异常现象

链路切换 Traffic Shifting

我们先把50%流量发送给reviews:v1 50%流量发送给v3,然后再把100%的流量都切给v3

把100%流量切到v1

kubectl apply -f samples/bookinfo/networking/virtual-service-all-v1.yaml

此时不论刷几遍,都没有星星

v1 v3各50%流量

kubectl apply -f samples/bookinfo/networking/virtual-service-reviews-50-v3.yaml
- route:
    - destination:
        host: reviews
        subset: v1
      weight: 50
    - destination:
        host: reviews
        subset: v3
      weight: 50

此时一会有星,一会没星,但是已经不是轮询算法了

全切v3

kubectl apply -f samples/bookinfo/networking/virtual-service-reviews-v3.yaml

这时不管怎么刷都是红心了

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