Spring Cloud Kubernetes 发现服务器

DeepSeek V3 中英对照 Spring Cloud Kubernetes Discovery Server

Spring Cloud Kubernetes 发现服务器提供了 HTTP 端点，应用程序可以使用这些端点来收集有关 Kubernetes 集群中可用服务的信息。使用 spring-cloud-starter-kubernetes-discoveryclient 的应用程序可以利用 Spring Cloud Kubernetes 发现服务器，为该启动器提供的 DiscoveryClient 实现提供数据。

权限

Spring Cloud Discovery 服务器使用 Kubernetes API 服务器来获取有关 Pod、Service 和 Endpoint 资源的数据，因此它需要 list、watch 和 get 权限来使用这些端点。请参见下面的 Kubernetes 部署 YAML 示例，了解如何在 Kubernetes 上配置 Service Account。

apiVersion: v1
kind: ServiceAccount
metadata:
  name: spring-cloud-discovery
  namespace: default
---
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  namespace: default
  name: spring-cloud-discovery-role
rules:
- apiGroups: [""]
  resources: ["pods", "services", "endpoints"]
  verbs: ["get", "list", "watch"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: spring-cloud-discovery-role-binding
  namespace: default
subjects:
- kind: ServiceAccount
  name: spring-cloud-discovery
  namespace: default
roleRef:
  kind: Role
  name: spring-cloud-discovery-role
  apiGroup: rbac.authorization.k8s.io

yaml

端点

服务器暴露了三个端点。

/apps

发送到 /apps 的 GET 请求将返回可用服务的 JSON 数组。每个项目包含 Kubernetes 服务的名称和服务实例信息。以下是一个示例响应。

[
   {
      "name":"spring-cloud-kubernetes-discoveryserver",
      "serviceInstances":[
         {
            "instanceId":"836a2f25-daee-4af2-a1be-aab9ce2b938f",
            "serviceId":"spring-cloud-kubernetes-discoveryserver",
            "host":"10.244.1.6",
            "port":8761,
            "uri":"http://10.244.1.6:8761",
            "secure":false,
            "metadata":{
               "app":"spring-cloud-kubernetes-discoveryserver",
               "kubectl.kubernetes.io/last-applied-configuration":"{\"apiVersion\":\"v1\",\"kind\":\"Service\",\"metadata\":{\"annotations\":{},\"labels\":{\"app\":\"spring-cloud-kubernetes-discoveryserver\"},\"name\":\"spring-cloud-kubernetes-discoveryserver\",\"namespace\":\"default\"},\"spec\":{\"ports\":[{\"name\":\"http\",\"port\":80,\"targetPort\":8761}],\"selector\":{\"app\":\"spring-cloud-kubernetes-discoveryserver\"},\"type\":\"ClusterIP\"}}\n",
               "http":"8761"
            },
            "namespace":"default",
            "scheme":"http"
         }
      ]
   },
   {
      "name":"kubernetes",
      "serviceInstances":[
         {
            "instanceId":"1234",
            "serviceId":"kubernetes",
            "host":"172.18.0.3",
            "port":6443,
            "uri":"http://172.18.0.3:6443",
            "secure":false,
            "metadata":{
               "provider":"kubernetes",
               "component":"apiserver",
               "https":"6443"
            },
            "namespace":"default",
            "scheme":"http"
         }
      ]
   }
]

json

/apps/{name}

对 /apps/{name} 的 GET 请求可用于获取给定服务的所有实例的实例数据。以下是对 /apps/kubernetes 进行 GET 请求时的示例响应。

[
     {
        "instanceId":"1234",
        "serviceId":"kubernetes",
        "host":"172.18.0.3",
        "port":6443,
        "uri":"http://172.18.0.3:6443",
        "secure":false,
        "metadata":{
           "provider":"kubernetes",
           "component":"apiserver",
           "https":"6443"
        },
        "namespace":"default",
        "scheme":"http"
     }
]

json

/app/{name}/{instanceid}

对 /app/{name}/{instanceid} 发起的 GET 请求将返回给定服务的特定实例的实例数据。以下是对 /app/kubernetes/1234 发起 GET 请求时的示例响应。

{
    "instanceId":"1234",
    "serviceId":"kubernetes",
    "host":"172.18.0.3",
    "port":6443,
    "uri":"http://172.18.0.3:6443",
    "secure":false,
    "metadata":{
       "provider":"kubernetes",
       "component":"apiserver",
       "https":"6443"
    },
    "namespace":"default",
    "scheme":"http"
 }

json

部署 YAML

Spring Cloud Discovery Server 的镜像托管在 Docker Hub 上。然而，如果你需要自定义发现服务器的行为，或者更倾向于自己构建镜像，你可以轻松地从 GitHub 上的源代码 构建自己的镜像并使用它。

以下是一个示例部署 YAML，您可以使用它将 Kubernetes Discovery Server 部署到 Kubernetes 中。

---
apiVersion: v1
kind: List
items:
  - apiVersion: v1
    kind: Service
    metadata:
      labels:
        app: spring-cloud-kubernetes-discoveryserver
      name: spring-cloud-kubernetes-discoveryserver
    spec:
      ports:
        - name: http
          port: 80
          targetPort: 8761
      selector:
        app: spring-cloud-kubernetes-discoveryserver
      type: ClusterIP
  - apiVersion: v1
    kind: ServiceAccount
    metadata:
      labels:
        app: spring-cloud-kubernetes-discoveryserver
      name: spring-cloud-kubernetes-discoveryserver
  - apiVersion: rbac.authorization.k8s.io/v1
    kind: RoleBinding
    metadata:
      labels:
        app: spring-cloud-kubernetes-discoveryserver
      name: spring-cloud-kubernetes-discoveryserver:view
    roleRef:
      kind: Role
      apiGroup: rbac.authorization.k8s.io
      name: namespace-reader
    subjects:
      - kind: ServiceAccount
        name: spring-cloud-kubernetes-discoveryserver
  - apiVersion: rbac.authorization.k8s.io/v1
    kind: Role
    metadata:
      namespace: default
      name: namespace-reader
    rules:
      - apiGroups: ["", "extensions", "apps"]
        resources: ["pods", "services", "endpoints"]
        verbs: ["get", "list", "watch"]
  - apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: spring-cloud-kubernetes-discoveryserver-deployment
    spec:
      selector:
        matchLabels:
          app: spring-cloud-kubernetes-discoveryserver
      template:
        metadata:
          labels:
            app: spring-cloud-kubernetes-discoveryserver
        spec:
          serviceAccountName: spring-cloud-kubernetes-discoveryserver
          containers:
          - name: spring-cloud-kubernetes-discoveryserver
            image: springcloud/spring-cloud-kubernetes-discoveryserver:3.1.0
            imagePullPolicy: IfNotPresent
            readinessProbe:
              httpGet:
                port: 8761
                path: /actuator/health/readiness
            livenessProbe:
              httpGet:
                port: 8761
                path: /actuator/health/liveness
            ports:
            - containerPort: 8761

yaml