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如何调试 MicroK8S 中的 Ingress Controller 为何指向错误的服务？

tag-icon • tag-icon kubernetes nginx-ingress microk8s
如何调试 MicroK8S 中的 Ingress Controller 为何指向错误的服务？

为了学习目的，我在家里搭建了一个小型的三节点 Kubernetes 集群。每个 16GB 节点运行 Ubuntu Server 和 MicroK8S。我设置了一个领导者（arran）和两个追随者（nikka 和 yamazaki）。

root@arran:/home/me# microk8s kubectl get nodes -o wide
NAME       STATUS   ROLES    AGE     VERSION   INTERNAL-IP      EXTERNAL-IP   OS-IMAGE             KERNEL-VERSION      CONTAINER-RUNTIME
arran      Ready    <none>   5d3h    v1.26.4   192.168.50.251   <none>        Ubuntu 22.04.2 LTS   5.15.0-71-generic   containerd://1.6.15
nikka      Ready    <none>   4d14h   v1.26.4   192.168.50.74    <none>        Ubuntu 22.04.2 LTS   5.15.0-71-generic   containerd://1.6.15
yamazaki   Ready    <none>   3d16h   v1.26.4   192.168.50.135   <none>        Ubuntu 22.04.2 LTS   5.15.0-71-generic   containerd://1.6.15

以下是集群的状态，已ingress手动dashboard启用。您可以看到它已切换到 HA 模式：

root@arran:/home/me# microk8s status
microk8s is running
high-availability: yes
  datastore master nodes: 192.168.50.251:19001 192.168.50.74:19001 192.168.50.135:19001
  datastore standby nodes: none
addons:
  enabled:
    dashboard            # (core) The Kubernetes dashboard
    ha-cluster           # (core) Configure high availability on the current node
    helm                 # (core) Helm - the package manager for Kubernetes
    helm3                # (core) Helm 3 - the package manager for Kubernetes
    hostpath-storage     # (core) Storage class; allocates storage from host directory
    ingress              # (core) Ingress controller for external access
    metrics-server       # (core) K8s Metrics Server for API access to service metrics
    registry             # (core) Private image registry exposed on localhost:32000
    storage              # (core) Alias to hostpath-storage add-on, deprecated
  disabled:
    cert-manager         # (core) Cloud native certificate management
    community            # (core) The community addons repository
    dns                  # (core) CoreDNS
    gpu                  # (core) Automatic enablement of Nvidia CUDA
    host-access          # (core) Allow Pods connecting to Host services smoothly
    kube-ovn             # (core) An advanced network fabric for Kubernetes
    mayastor             # (core) OpenEBS MayaStor
    metallb              # (core) Loadbalancer for your Kubernetes cluster
    minio                # (core) MinIO object storage
    observability        # (core) A lightweight observability stack for logs, traces and metrics
    prometheus           # (core) Prometheus operator for monitoring and logging
    rbac                 # (core) Role-Based Access Control for authorisation

以下是我正在运行的 pod，它们来自我的清单（见下文）：

root@arran:/home/me# microk8s kubectl get pods -o wide
NAME                               READY   STATUS    RESTARTS      AGE    IP             NODE       NOMINATED NODE   READINESS GATES
hello-world-app                    1/1     Running   1 (14h ago)   47h    10.1.134.199   yamazaki   <none>           <none>
my-pod                             1/1     Running   2 (14h ago)   5d1h   10.1.150.208   arran      <none>           <none>

目前提供的服务如下：

root@arran:/home/me# microk8s kubectl get services -o wide
NAME                  TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)         AGE     SELECTOR
kubernetes            ClusterIP   10.152.183.1     <none>        443/TCP         5d3h    <none>
nginx-service         NodePort    10.152.183.120   <none>        80:30000/TCP    2d12h   app.kubernetes.io/name=hello-world-app
hello-world-service   NodePort    10.152.183.205   <none>        80:30032/TCP    47h     app.kubernetes.io/name=hello-world-app
dashboard-service     NodePort    10.152.183.237   <none>        443:32589/TCP   47h     app.kubernetes.io/name=kubernetes

我怀疑问题出在清单中，它是我从 K8S 和 MicroK8s 手册中以复制粘贴的方式构建的：

apiVersion: v1
kind: Pod
metadata:
  name: hello-world-app
  labels:
    app.kubernetes.io/name: hello-world-app
spec:
  containers:
    - name: nginx
      image: nginx:latest
      ports:
        - name: http
          containerPort: 80
          protocol: TCP

---

apiVersion: v1
kind: Service
metadata:
  name: hello-world-service
spec:
  selector:
    app.kubernetes.io/name: hello-world-app
  ports:
  - port: 80
    targetPort: 80
  type: NodePort

---

# Not sure this will work - do we need a NodePort to the dashboard?
apiVersion: v1
kind: Service
metadata:
  name: dashboard-service
spec:
  selector:
    app.kubernetes.io/name: kubernetes
  ports:
  - port: 443
    targetPort: 443
  type: NodePort

---

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: http-ingress
spec:
  rules:
  - http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: nginx-service
            port:
              number: 80

---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: dashboard-ingress
spec:
  rules:
  - http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: kubernetes
            port:
              number: 443

现在，我有一个“hello world”应用程序，我给它一个节点端口，然后使用入口插件将其公开。这已在http://192.168.50.251/（端口 80）。但是，我尝试对 Kubernetes 仪表板执行相同操作，方法是添加端口和入口路由（端口 443），但https://192.168.50.251/指向“hello world”而不是我想要的仪表板。

单文件清单文件已完全应用microk8s kubectl apply -f manifest.yml。

下一步我可以尝试什么？

答案1

我用一种非常不同的方法解决了这个问题，根本不需要清单。MicroK8S 提供了一些辅助脚本来实现这一点。我需要 K8S 主服务器上的两个会话。

在第一个会话中，我运行了这个：

root@arran:/home/me# microk8s dashboard-proxy
Checking if Dashboard is running.
Infer repository core for addon dashboard
Waiting for Dashboard to come up.
Trying to get token from microk8s-dashboard-token
Waiting for secret token (attempt 0)
Dashboard will be available at https://127.0.0.1:10443
Use the following token to login:
eyJhbGciOiJSUzI1NiIsImtpZCI6IkJ1US1DZEVmUjM2ZWZZcjg5UTh5eXdQUFpLYnNpMVV1YWZPM0o2ZEEtQlUifQ.eyJpc3JiOiJrdWJlcm5ldGVzL3NlcnZpY2VhY2NvdW50Iiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9uYW1lc3BhY2UiOiJrdWJlLXN5c3RlbSIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VjcmV0Lm5hbWUiOiJtaWNyb2s4cy1kYXNoYm9hcmQtdG9rZW4iLCJrdWJlcm5ldGVzLmlvL3NlcnZpY2VhY2NvdW50L3NlcnZpY2UtYWNjb3VudC5uYW1lIjoiZGVmYXVsdCIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VydmljZS1hY2NvdW50LnVpZCI6IjA1M2Y3ZThhLTFiNWUtNDFkZi1hMmI0LWFlNzY3M2ZlZmMwNyIsInN1YiI6InN5c3RlbTpzZXJ2aWNlYWNjb3VudDprdWJlLXN5c3RlbTpkZWZhdWx0In0.EL1IfT8lh1gT7VKYHrWzZlNLhxP8kWKzZPdxzi7IL2Il9zL4Pg3ZMI5YmCv5s-IrVIKmUfFGsHu4G30gcqmg0FdkBhPkBSOvmfnB77mGjCMGSaIToHIySI_9HBB3Ea3i91bx_n9TJC3DVIKtEVdLx3p73_ygQBUmZ0QUs4MUf1mAIBkL7ltq58y9CUr88nuLWnQ2oUiIdtRpnz4Tw2V8Bin5rWQj2af_PeVKGfxBJBTsmmUADdby8vjZ-GTWCTcCZ3IEbLTx9jsWsf9qb2KYohnCfXBJPx8WbGw8Hkyvm3DjrjtzfZyiW4rPLTD7v8Oo0GimUrpBm6hZWmTd8rixQg

在第二个会话中我运行了这个：

root@arran:/home/me# microk8s kubectl port-forward -n kube-system service/kubernetes-dashboard 8080:443 --address='0.0.0.0'
Forwarding from 0.0.0.0:8080 -> 8443

然后，K8S 仪表板就会在领导主机上公开：https://192.168.50.251:8080/。从这里，只需粘贴上面的长令牌即可登录。

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