使用外部-dns.alpha.kubernetes.io为EKS fargate入口alb动态设置外部dns

Question

我正在尝试从Eks清单文件设置外部dns。

我创建了EKS集群，并创建了3个fargate配置文件: default、kube-system和dev。Coredns pods已经启动并运行。

然后，我按照本文档安装了AWS负载均衡器控制器。在kube-system中出现了负载均衡控制器https://docs.aws.amazon.com/eks/latest/userguide/aws-load-balancer-controller.html。

然后，我使用以下清单文件安装了外部dns部署。

    apiVersion: v1
    kind: ServiceAccount
    metadata:
      name: external-dns
      namespace: kube-system
      annotations:
         eks.amazonaws.com/role-arn: arn:aws:iam::xxxxxxxxx:role/eks-externaldnscontrollerRole-XST756O4A65B
    ---

apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRole
metadata:
  name: external-dns
rules:
- apiGroups: [""]
  resources: ["services"]
  verbs: ["get","watch","list"]
- apiGroups: [""]
  resources: ["pods"]
  verbs: ["get","watch","list"]
- apiGroups: ["extensions"]
  resources: ["ingresses"]
  verbs: ["get","watch","list"]
- apiGroups: [""]
  resources: ["nodes"]
  verbs: ["list"]
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
  name: external-dns-viewer
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: external-dns
subjects:
- kind: ServiceAccount
  name: external-dns
  namespace: kube-system
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: external-dns
  namespace: kube-system
spec:
  selector:
    matchLabels:
      app: external-dns
  strategy:
    type: Recreate
  template:
    metadata:
      labels:
        app: external-dns
    spec:
      serviceAccountName: external-dns
      containers:
      - name: external-dns
        image: bitnami/external-dns:0.7.1
        args:
        - --source=service
        - --source=ingress
        #- --domain-filter=xxxxxxxxxx.com # will make ExternalDNS see only the hosted zones matching provided domain, omit to process all available hosted zones
        - --provider=aws
        #- --policy=upsert-only # would prevent ExternalDNS from deleting any records, omit to enable full synchronization
        - --aws-zone-type=public # only look at public hosted zones (valid values are public, private or no value for both)
        - --registry=txt
        - --txt-owner-id=my-identifier
      #securityContext:
      #  fsGroup: 65534

对于外部dns，我使用了kube-system和dev两个名称空间，结果都很好。

然后我部署了应用程序和入口清单文件。我使用了两个名称空间: kube-system和dev。

apiVersion: apps/v1
kind: Deployment
metadata:
  name: app1-nginx-deployment
  labels:
    app: app1-nginx
  namespace: kube-system
spec:
  replicas: 2
  selector:
    matchLabels:
      app: app1-nginx
  template:
    metadata:
      labels:
        app: app1-nginx
    spec:
      containers:
        - name: app1-nginx
          image: kube-nginxapp1:1.0.0
          ports:
            - containerPort: 80
          resources:
            requests:
              memory: "128Mi"
              cpu: "500m"
            limits:
              memory: "500Mi"
              cpu: "1000m"
---
apiVersion: v1
kind: Service
metadata:
  name: app1-nginx-nodeport-service
  labels:
    app: app1-nginx
  namespace: kube-system
  annotations:
#Important Note:  Need to add health check path annotations in service level if we are planning to use multiple targets in a load balancer
    alb.ingress.kubernetes.io/healthcheck-path: /app1/index.html
spec:
  type: NodePort
  selector:
    app: app1-nginx
  ports:
    - port: 80
      targetPort: 80


----------

# Annotations Reference:  https://kubernetes-sigs.github.io/aws-alb-ingress-controller/guide/ingress/annotation/
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ingress-usermgmt-restapp-service
  labels:
    app: usermgmt-restapp
  namespace: kube-system
  annotations:
    # Ingress Core Settings
    alb.ingress.kubernetes.io/scheme: internet-facing
    kubernetes.io/ingress.class: alb
    # Health Check Settings
    alb.ingress.kubernetes.io/healthcheck-protocol: HTTP
    alb.ingress.kubernetes.io/healthcheck-port: traffic-port
    #Important Note:  Need to add health check path annotations in service level if we are planning to use multiple targets in a load balancer
    #alb.ingress.kubernetes.io/healthcheck-path: /usermgmt/health-status
    alb.ingress.kubernetes.io/healthcheck-interval-seconds: '15'
    alb.ingress.kubernetes.io/healthcheck-timeout-seconds: '5'
    alb.ingress.kubernetes.io/success-codes: '200'
    alb.ingress.kubernetes.io/healthy-threshold-count: '2'
    alb.ingress.kubernetes.io/unhealthy-threshold-count: '2'
    ## SSL Settings
    alb.ingress.kubernetes.io/listen-ports: '[{"HTTPS":443}, {"HTTP":80}]'
    alb.ingress.kubernetes.io/certificate-arn: arn:aws:acm:us-east-1:0xxxxxxxxxx:certificate/0xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
    #alb.ingress.kubernetes.io/ssl-policy: ELBSecurityPolicy-TLS-1-1-2017-01 #Optional (Picks default if not used)
    # SSL Redirect Setting
    alb.ingress.kubernetes.io/actions.ssl-redirect: '{"Type": "redirect", "RedirectConfig": { "Protocol": "HTTPS", "Port": "443", "StatusCode": "HTTP_301"}}'
    # External DNS - For creating a Record Set in Route53
    external-dns.alpha.kubernetes.io/hostname: palb.xxxxxxx.com
    # For Fargate
    alb.ingress.kubernetes.io/target-type: ip
spec:
  rules:
    - http:
        paths:
          - path: /* # SSL Redirect Setting
            pathType: ImplementationSpecific
            backend:
              service:
                name: ssl-redirect
                port:
                  name: use-annotation
          - path: /*
            pathType: ImplementationSpecific
            backend:
              service:
                name: app1-nginx-nodeport-service
                port:
                  number: 80

所有pod都正常运行，但它没有动态注册thr alb的dns别名。你能指导我知道我出了什么问题吗？

Answer 1

首先，检查入口本身是否正常工作。检查AWS负载均衡器和负载均衡器目标组。目标组目标应处于活动状态。如果您执行kubectl get ingress，则还应输出所创建的负载均衡器的DNS名称。使用curl检查此url是否正常！注释external-dns.alpha.kubernetes.io/hostname: palb.xxxxxxx.com不适用于入口。仅对服务有效。但你不需要它。只需为入口spec.rules指定host字段。在您的示例中没有这样的属性。指定它！