kubernetes - rfc7231＃section-6.5.1 Kubernetes上的dotnet核心入口 Controller api访问问题

Question

我已经在Kubernetes中部署了一个简单的dotnet核心应用程序。公开的服务如下

apiVersion: v1
kind: Service
metadata:
  creationTimestamp: "2020-01-17T18:07:23Z"
  labels:
    app.kubernetes.io/instance: expo-api
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/name: expo-api
    app.kubernetes.io/version: 0.0.4
    helm.sh/chart: expo-api-0.0.4
  name: expo-api-service
  namespace: default
  resourceVersion: "997971"
  selfLink: /api/v1/namespaces/default/services/expo-api-service
  uid: 144b9d1d-87d2-4096-9851-9563266b2099
spec:
  clusterIP: 10.12.0.122
  ports:
  - name: http
    port: 80
    protocol: TCP
    targetPort: http
  selector:
    app.kubernetes.io/instance: expo-api
    app.kubernetes.io/name: expo-api
  sessionAffinity: None
  type: ClusterIP
status:
  loadBalancer: {}

我正在使用的入口 Controller 是nginx入口 Controller ，简单的入口规则设置如下-

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  annotations:
    kubernetes.io/ingress.class: nginx
    nginx.ingress.kubernetes.io/use-regex: "true"
  creationTimestamp: "2020-01-17T18:07:24Z"
  generation: 3
  labels:
    app.kubernetes.io/instance: expo-api
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/name: expo-api
    app.kubernetes.io/version: 0.0.4
    helm.sh/chart: expo-api-0.0.4
  name: expo-api
  namespace: default
  resourceVersion: "1004650"
  selfLink: /apis/extensions/v1beta1/namespaces/default/ingresses/expo-api
  uid: efef4e15-ed0a-417f-8b34-4e0f46cb1e70
spec:
  rules:
  - http:
      paths:
      - backend:
          serviceName: expo-api-service
          servicePort: 80
        path: /expense
status:
  loadBalancer:
    ingress:
    - ip: 34.70.45.62

启动简单的dotnet核心应用-

public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddControllers();
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }
            app.UseHttpsRedirection();
            app.UseRouting();
            app.UseAuthorization();
            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllers();
            });
        }
    }

这是入口输出-

Name:             expo-api
Namespace:        default
Address:          34.70.45.62
Default backend:  default-http-backend:80 (10.8.0.9:8080)
Rules:
  Host  Path  Backends
  ----  ----  --------
  *     
        /expense   expo-api-service:80 (10.8.0.26:80,10.8.0.27:80,10.8.1.14:80)
Annotations:
  kubernetes.io/ingress.class:            nginx
  nginx.ingress.kubernetes.io/use-regex:  true
Events:                                   <none>

以下是Nginx入口 Controller 的设置-

Name:                     nginx-nginx-ingress-controller
Namespace:                default
Labels:                   app=nginx-ingress
                          chart=nginx-ingress-1.29.2
                          component=controller
                          heritage=Helm
                          release=nginx
Annotations:              <none>
Selector:                 app=nginx-ingress,component=controller,release=nginx
Type:                     LoadBalancer
IP:                       10.12.0.107
LoadBalancer Ingress:     34.66.164.70
Port:                     http  80/TCP
TargetPort:               http/TCP
NodePort:                 http  30144/TCP
Endpoints:                10.8.1.6:80
Port:                     https  443/TCP
TargetPort:               https/TCP
NodePort:                 https  30469/TCP
Endpoints:                10.8.1.6:443
Session Affinity:         None
External Traffic Policy:  Cluster
Events:                   <none>

问题是，当我将入口规则路径更改为仅 /并使用- curl 34.66.164.70/weatherforecast进行访问时，它可以很好地工作。

但是，当我将入口路径更改为 /expense并尝试使用-curl 34.66.164.70/expense/weatherforecast进行访问时。输出错误为-

{
  "type": "https://tools.ietf.org/html/rfc7231#section-6.5.1",
  "title": "One or more validation errors occurred.",
  "status": 400,
  "traceId": "|4dec8cf0-4fddb4d168cb9569.",
  "errors": {
    "id": [
      "The value 'weatherforecast' is not valid."
    ]
  }
}

我无法理解这背后的问题是什么。它是从dotnet核心还是Kubernetes出现的？如果是dotnet，可能是什么分辨率，如果在Kubernetes上，则是预期的分辨率。

Answer 1

更新了1

我在您的Ingress对象中看不到nginx.ingress.kubernetes.io/rewrite-target批注。无法说出是否有意跳过了它。

如果不存在此注释，则您的应用程序会收到“GET:/ expense / weatherforecast”。如果这是您想要的，一切都会很好。但是，如果您希望您的应用收到“GET:/ weatherforecast”，则应在您的Ingress注释中添加nginx.ingress.kubernetes.io/rewrite-target: /。

更新了2

Ingress-nginx文档包含有关“重写”注释的文章:
https://kubernetes.github.io/ingress-nginx/examples/rewrite/#rewrite-target

有一个非常简洁的示例，可以帮助您了解如何公开/expense/weatherforecast端点。但不幸的是，我也无法实现/expense公开。我尝试了更复杂的正则表达式，并尝试了该文章中的“app-root”注释，但没有任何效果-Ingress始终返回404的/expense endpoinnt。

我找不到有关如何处理根端点和相对端点的任何有用信息，因此我开始即兴创作。我发现您可以使用两个支持的路径来使其工作。不知道这是否是错误或功能:)。

遵循Ingress规范对我的测试应用程序非常有效。它可以正确处理/expense和/expense/weatherforecast。

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  annotations:
    kubernetes.io/ingress.class: "nginx"
    # nginx.ingress.kubernetes.io/use-regex: "true" # can be true or false, no matter
    nginx.ingress.kubernetes.io/rewrite-target: "/$1"
  name: app
spec:
  rules:
  - http:
      paths:
      - backend:
          serviceName: app
          servicePort: 80
        path: "/expense/(.+)" # handle relative path
      - backend: 
          serviceName: app
          servicePort: 80
        path: "/expense" # handle root