istio-流量管理-延迟故障访问注入 istio-流量管理-延迟故障访问注入

第一步还是需要移除之前创建的 VirtualService

[root@k8s-master ~]# istioctl delete virtualservice reviews
Command "delete" is deprecated, Use `kubectl delete` instead (see https://kubernetes.io/docs/tasks/tools/install-kubectl)
Deleted config: virtualservice reviews
[root@k8s-master ~]# istioctl get virtualservice
Command "get" is deprecated, Use `kubectl get` instead (see https://kubernetes.io/docs/tasks/tools/install-kubectl)
VIRTUAL-SERVICE NAME   GATEWAYS           HOSTS     #HTTP     #TCP      NAMESPACE   AGE
bookinfo               bookinfo-gateway   *             1        0      default     3d
[root@k8s-master ~]#

然后我们查看 istio 样例文件夹下面的文件：samples/bookinfo/networking/virtual-service-ratings-test-delay.yaml 的内容

# cat samples/bookinfo/networking/virtual-service-ratings-test-delay.yaml
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: ratings
spec:
  hosts:
  - ratings
  http:
  - match:
    - headers:
        end-user:
          exact: jason
    fault:
      delay:
        percentage:
          value: 100.0
        fixedDelay: 7s
    route:
    - destination:
        host: ratings
        subset: v1
  - route:
    - destination:
        host: ratings
        subset: v1

这个 VirtualService 定义了一个在 jason 登录的情况下，访问 ratings 服务的 100% 的 7s 访问延迟。前面我们知道，Bookinfo 这个示例 productpage 服务调用 reviews，reviews 的不同版本会对 ratings 进行不同的调用，其中 reviews-v1 不调用 ratings，reviews-v2 和 reviews-v3 会调用 ratings，并做不同样式的渲染。并且在 productpage 访问 reviews 时，代码中有硬编码 6s 中的访问超时限制，而 reviews 访问 ratings 编码了 10s 的访问超时限制。

[root@k8s-master istio-1.3.1]#  kubectl create -f  samples/bookinfo/networking/virtual-service-ratings-test-delay.yaml
The VirtualService "ratings" is invalid: []: Invalid value: map[string]interface {}{"apiVersion":"networking.istio.io/v1alpha3", "kind":"VirtualService", "metadata":map[string]interface {}{"creationTimestamp":"2019-11-11T07:31:13Z", "generation":1, "name":"ratings", "namespace":"default", "uid":"0e9e1bbe-6060-4c0b-95af-42b9bf306c64"}, "spec":map[string]interface {}{"hosts":[]interface {}{"ratings"}, "http":[]interface {}{map[string]interface {}{"fault":map[string]interface {}{"delay":map[string]interface {}{"fixedDelay":"7s", "percentage":map[string]interface {}{"value":100}}}, "match":[]interface {}{map[string]interface {}{"headers":map[string]interface {}{"end-user":map[string]interface {}{"exact":"jason"}}}}, "route":[]interface {}{map[string]interface {}{"destination":map[string]interface {}{"host":"ratings", "subset":"v1"}}}}, map[string]interface {}{"route":[]interface {}{map[string]interface {}{"destination":map[string]interface {}{"host":"ratings", "subset":"v1"}}}}}}}: validation failure list:
spec.http.route.weight in body is required
[root@k8s-master istio-1.3.1]# vim   samples/bookinfo/networking/virtual-service-ratings-test-delay.yaml
[root@k8s-master istio-1.3.1]#  kubectl apply -f  samples/bookinfo/networking/virtual-service-ratings-test-delay.yaml
virtualservice.networking.istio.io/ratings created
[root@k8s-master istio-1.3.1]# cat    samples/bookinfo/networking/virtual-service-ratings-test-delay.yaml
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: ratings
spec:
  hosts:
  - ratings
  http:
  - match:
    - headers:
        end-user:
          exact: jason
    fault:
      delay:
        percentage:
          value: 100.0
        fixedDelay: 7s
    route:
    - destination:
        host: ratings
        subset: v1
      weight: 1
  - route:
    - destination:
        host: ratings
        subset: v1
      weight: 1

创建完成后，前往 Bookinfo 应用，登录 jason，打开浏览器的Network，刷新页面，发现请求加载很慢，大约 6s 后，出现如下界面：

istio-流量管理-延迟故障访问注入
istio-流量管理-延迟故障访问注入

看到 productpage 的请求大约耗时 6s，Reviews显示 unavailable 的错误。因为此时 reviews 请求 ratings 的访问超过了 6s 还没有响应，使得 productpage 中的硬编码的超时设置生效了。

当然有的时候我们也能成功访问到 reviews-v1 版本，因为此时并没有进一步访问 ratings 服务，所以一切都是正常的，会显示不带星的界面：

istio-流量管理-延迟故障访问注入
istio-流量管理-延迟故障访问注入

通过这种超时故障注入，可以帮助我们方便地发现服务间相互访问中存在的潜在问题。

istio-流量管理-延迟故障访问注入 istio-流量管理-延迟故障访问注入

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