Kubernetes Nginx Ingress Controller on NodePort

Question

I am deploying the nginx based ingress controller on Kubernetes cluster managed by RKE. ( I have also tried the same directly without RKE ).

In both the cases , it tries to use/bind to Ports 80 , and 443 on the host, and it fails because in the pod security policy for all service accounts I am not allowing host ports.

In fact I don't need to access the ingress directly on the hosts, but I want to access the ingress controller as a Service on the NodePort from external LoadBalancer.

Is there way to deploy Nginx ingress controller not to use any hostPort.

Answer 1

Done by disabling hostNetwork , and remove unnecessary privileges and capabilities:

C02W84XMHTD5:Downloads iahmad$ kubectl get deployments -n ingress-nginx -o yaml
apiVersion: v1
items:
- apiVersion: extensions/v1beta1
  kind: Deployment
  metadata:
    annotations:
      deployment.kubernetes.io/revision: "1"

    labels:
      app.kubernetes.io/name: ingress-nginx
      app.kubernetes.io/part-of: ingress-nginx
    name: nginx-ingress-controller
    namespace: ingress-nginx
    resourceVersion: "68427"
    selfLink: /apis/extensions/v1beta1/namespaces/ingress-nginx/deployments/nginx-ingress-controller
    uid: 0b92b556-12fa-11ea-9d82-08002762a3c5
  spec:
    progressDeadlineSeconds: 600
    replicas: 1
    revisionHistoryLimit: 10
    selector:
      matchLabels:
        app.kubernetes.io/name: ingress-nginx
        app.kubernetes.io/part-of: ingress-nginx
    strategy:
      rollingUpdate:
        maxSurge: 25%
        maxUnavailable: 25%
      type: RollingUpdate
    template:
      metadata:
        annotations:
          prometheus.io/port: "10254"
          prometheus.io/scrape: "true"
        creationTimestamp: null
        labels:
          app.kubernetes.io/name: ingress-nginx
          app.kubernetes.io/part-of: ingress-nginx
      spec:
        containers:
        - args:
          - /nginx-ingress-controller
          - --configmap=$(POD_NAMESPACE)/nginx-configuration
          - --tcp-services-configmap=$(POD_NAMESPACE)/tcp-services
          - --udp-services-configmap=$(POD_NAMESPACE)/udp-services
          - --publish-service=$(POD_NAMESPACE)/ingress-nginx
          - --annotations-prefix=nginx.ingress.kubernetes.io
          env:
          - name: POD_NAME
            valueFrom:
              fieldRef:
                apiVersion: v1
                fieldPath: metadata.name
          - name: POD_NAMESPACE
            valueFrom:
              fieldRef:
                apiVersion: v1
                fieldPath: metadata.namespace
          image: quay.io/kubernetes-ingress-controller/nginx-ingress-controller:0.26.1
          imagePullPolicy: IfNotPresent
          lifecycle:
            preStop:
              exec:
                command:
                - /wait-shutdown
          livenessProbe:
            failureThreshold: 3
            httpGet:
              path: /healthz
              port: 10254
              scheme: HTTP
            initialDelaySeconds: 10
            periodSeconds: 10
            successThreshold: 1
            timeoutSeconds: 10
          name: nginx-ingress-controller
          ports:
          - containerPort: 80
            name: http
            protocol: TCP
          - containerPort: 443
            name: https
            protocol: TCP
          readinessProbe:
            failureThreshold: 3
            httpGet:
              path: /healthz
              port: 10254
              scheme: HTTP
            periodSeconds: 10
            successThreshold: 1
            timeoutSeconds: 10
          resources: {}
          securityContext:
            runAsUser: 33
          terminationMessagePath: /dev/termination-log
          terminationMessagePolicy: File
        dnsPolicy: ClusterFirst
        restartPolicy: Always
        schedulerName: default-scheduler
        securityContext: {}
        serviceAccount: nginx-ingress-serviceaccount
        serviceAccountName: nginx-ingress-serviceaccount
        terminationGracePeriodSeconds: 300
  status:
    availableReplicas: 1
    conditions:
    - lastTransitionTime: 2019-11-29T22:46:59Z
      lastUpdateTime: 2019-11-29T22:46:59Z
      message: Deployment has minimum availability.
      reason: MinimumReplicasAvailable
      status: "True"
      type: Available
    - lastTransitionTime: 2019-11-29T22:46:13Z
      lastUpdateTime: 2019-11-29T22:46:59Z
      message: ReplicaSet "nginx-ingress-controller-84758fb96c" has successfully progressed.
      reason: NewReplicaSetAvailable
      status: "True"
      type: Progressing
    observedGeneration: 1
    readyReplicas: 1
    replicas: 1
    updatedReplicas: 1
kind: List
metadata:
  resourceVersion: ""
  selfLink: ""

and then creating a nodeport service pointing to the ingress controller ports:

C02W84XMHTD5:Downloads iahmad$ kubectl get svc -n ingress-nginx -o yaml
apiVersion: v1
items:
- apiVersion: v1
  kind: Service
  metadata:

    labels:
      app.kubernetes.io/name: ingress-nginx
      app.kubernetes.io/part-of: ingress-nginx
    name: ingress-nginx
    namespace: ingress-nginx
    resourceVersion: "68063"
    selfLink: /api/v1/namespaces/ingress-nginx/services/ingress-nginx
    uid: 7aa425a4-12f9-11ea-9d82-08002762a3c5
  spec:
    clusterIP: 10.97.110.93
    externalTrafficPolicy: Cluster
    ports:
    - name: http
      nodePort: 30864
      port: 80
      protocol: TCP
      targetPort: 80
    - name: https
      nodePort: 30716
      port: 443
      protocol: TCP
      targetPort: 443
    selector:
      app.kubernetes.io/name: ingress-nginx
      app.kubernetes.io/part-of: ingress-nginx
    sessionAffinity: None
    type: NodePort
  status:
    loadBalancer: {}
kind: List
metadata:
  resourceVersion: ""
  selfLink: ""
C02W84XMHTD5:Downloads iahmad$