How to access k8S internal service -ingress

1. The background

The common way for clients to access k8S internal services is to set service.type to nodeport, which is mapped to the IP address of the K8S service using the physical server IP address + nodePort. However, nodeport occupies physical machine port resources, and the number of ports is limited (the default port number ranges from 30000 to 32767). Therefore, this article describes how to map k8S internal services through ingress. There are many ingress controllers. Ingress-nginx, ingress-Traefik,istio ingress, etc.

The use of nginx and Traefik will be highlighted below.

2. ingress-nginx

2.1 the deployment

Yaml files are prepared

Myapp service yamL file, service mapping port 8000

apiVersion: v1
kind: Service 
metadata:
  name: webapp-svc
  labels:
    app: webapp-svc
spec:
  type: NodePort 
  ports:
  - port: 8000
    targetPort: 8000
  selector:
   app: webapp 
---
apiVersion: extensions/v1beta1 
kind: Deployment
metadata:
   name: webapp-deploy
   labels:
     app: webapp-deploy
spec:
  replicas: 1
  template:
    metadata: 
      labels:
        app: webapp
    spec: 
      containers:
      - name: webapp
        image: hub.geovis.io/zhangjx/flask:app 
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Ingress-nginx yamL deployment file

apiVersion: v1
kind: Namespace
metadata:
  name: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx

---
# Source: ingress-nginx/templates/controller-serviceaccount.yaml
apiVersion: v1
kind: ServiceAccount
metadata:
  labels:
    helm.sh/chart: ingress-nginx-2.13.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.35.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: ingress-nginx
  namespace: ingress-nginx
---
# Source: ingress-nginx/templates/controller-configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  labels:
    helm.sh/chart: ingress-nginx-2.13.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.35.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: ingress-nginx-controller
  namespace: ingress-nginx
data:
---
# Source: ingress-nginx/templates/clusterrole.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  labels:
    helm.sh/chart: ingress-nginx-2.13.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.35.0
    app.kubernetes.io/managed-by: Helm
  name: ingress-nginx
rules:
  - apiGroups:
      - ''
    resources:
      - configmaps
      - endpoints
      - nodes
      - pods
      - secrets
    verbs:
      - list
      - watch
  - apiGroups:
      - ''
    resources:
      - nodes
    verbs:
      - get
  - apiGroups:
      - ''
    resources:
      - services
    verbs:
      - get
      - list
      - update
      - watch
  - apiGroups:
      - extensions
      - networking.k8s.io   # k8s 1.14+
    resources:
      - ingresses
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - ''
    resources:
      - events
    verbs:
      - create
      - patch
  - apiGroups:
      - extensions
      - networking.k8s.io   # k8s 1.14+
    resources:
      - ingresses/status
    verbs:
      - update
  - apiGroups:
      - networking.k8s.io   # k8s 1.14+
    resources:
      - ingressclasses
    verbs:
      - get
      - list
      - watch
---
# Source: ingress-nginx/templates/clusterrolebinding.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  labels:
    helm.sh/chart: ingress-nginx-2.13.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.35.0
    app.kubernetes.io/managed-by: Helm
  name: ingress-nginx
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: ingress-nginx
subjects:
  - kind: ServiceAccount
    name: ingress-nginx
    namespace: ingress-nginx
---
# Source: ingress-nginx/templates/controller-role.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  labels:
    helm.sh/chart: ingress-nginx-2.13.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.35.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: ingress-nginx
  namespace: ingress-nginx
rules:
  - apiGroups:
      - ''
    resources:
      - namespaces
    verbs:
      - get
  - apiGroups:
      - ''
    resources:
      - configmaps
      - pods
      - secrets
      - endpoints
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - ''
    resources:
      - services
    verbs:
      - get
      - list
      - update
      - watch
  - apiGroups:
      - extensions
      - networking.k8s.io   # k8s 1.14+
    resources:
      - ingresses
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - extensions
      - networking.k8s.io   # k8s 1.14+
    resources:
      - ingresses/status
    verbs:
      - update
  - apiGroups:
      - networking.k8s.io   # k8s 1.14+
    resources:
      - ingressclasses
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - ''
    resources:
      - configmaps
    resourceNames:
      - ingress-controller-leader-nginx
    verbs:
      - get
      - update
  - apiGroups:
      - ''
    resources:
      - configmaps
    verbs:
      - create
  - apiGroups:
      - ''
    resources:
      - endpoints
    verbs:
      - create
      - get
      - update
  - apiGroups:
      - ''
    resources:
      - events
    verbs:
      - create
      - patch
---
# Source: ingress-nginx/templates/controller-rolebinding.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  labels:
    helm.sh/chart: ingress-nginx-2.13.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.35.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: ingress-nginx
  namespace: ingress-nginx
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: ingress-nginx
subjects:
  - kind: ServiceAccount
    name: ingress-nginx
    namespace: ingress-nginx
---
# Source: ingress-nginx/templates/controller-service-webhook.yaml
apiVersion: v1
kind: Service
metadata:
  labels:
    helm.sh/chart: ingress-nginx-2.13.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.35.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: ingress-nginx-controller-admission
  namespace: ingress-nginx
spec:
  type: ClusterIP
  ports:
    - name: https-webhook
      port: 443
      targetPort: webhook
  selector:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/component: controller
---
# Source: ingress-nginx/templates/controller-service.yaml
apiVersion: v1
kind: Service
metadata:
  labels:
    helm.sh/chart: ingress-nginx-2.13.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.35.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: ingress-nginx-controller
  namespace: ingress-nginx
spec:
  type: NodePort
  ports:
    - name: http
      port: 80
      protocol: TCP
      targetPort: http
    - name: https
      port: 443
      protocol: TCP
      targetPort: https
  selector:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/component: controller
---
# Source: ingress-nginx/templates/controller-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    helm.sh/chart: ingress-nginx-2.13.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.35.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: ingress-nginx-controller
  namespace: ingress-nginx
spec:
  selector:
    matchLabels:
      app.kubernetes.io/name: ingress-nginx
      app.kubernetes.io/instance: ingress-nginx
      app.kubernetes.io/component: controller
  revisionHistoryLimit: 10
  minReadySeconds: 0
  template:
    metadata:
      labels:
        app.kubernetes.io/name: ingress-nginx
        app.kubernetes.io/instance: ingress-nginx
        app.kubernetes.io/component: controller
    spec:
      dnsPolicy: ClusterFirst
      containers:
        - name: controller
          image: k8s.gcr.io/ingress-nginx/controller:v0.35.0@sha256:fc4979d8b8443a831c9789b5155cded454cb7de737a8b727bc2ba0106d2eae8b
          imagePullPolicy: IfNotPresent
          lifecycle:
            preStop:
              exec:
                command:
                  - /wait-shutdown
          args:
            - /nginx-ingress-controller
            - --election-id=ingress-controller-leader
            - --ingress-class=nginx
            - --configmap=$(POD_NAMESPACE)/ingress-nginx-controller
            - --validating-webhook=:8443
            - --validating-webhook-certificate=/usr/local/certificates/cert
            - --validating-webhook-key=/usr/local/certificates/key
          securityContext:
            capabilities:
              drop:
                - ALL
              add:
                - NET_BIND_SERVICE
            runAsUser: 101
            allowPrivilegeEscalation: true
          env:
            - name: POD_NAME
              valueFrom:
                fieldRef:
                  fieldPath: metadata.name
            - name: POD_NAMESPACE
              valueFrom:
                fieldRef:
                  fieldPath: metadata.namespace
          livenessProbe:
            httpGet:
              path: /healthz
              port: 10254
              scheme: HTTP
            initialDelaySeconds: 10
            periodSeconds: 10
            timeoutSeconds: 1
            successThreshold: 1
            failureThreshold: 5
          readinessProbe:
            httpGet:
              path: /healthz
              port: 10254
              scheme: HTTP
            initialDelaySeconds: 10
            periodSeconds: 10
            timeoutSeconds: 1
            successThreshold: 1
            failureThreshold: 3
          ports:
            - name: http
              containerPort: 80
              protocol: TCP
            - name: https
              containerPort: 443
              protocol: TCP
            - name: webhook
              containerPort: 8443
              protocol: TCP
          volumeMounts:
            - name: webhook-cert
              mountPath: /usr/local/certificates/
              readOnly: true
          resources:
            requests:
              cpu: 100m
              memory: 90Mi
      serviceAccountName: ingress-nginx
      terminationGracePeriodSeconds: 300
      volumes:
        - name: webhook-cert
          secret:
            secretName: ingress-nginx-admission
---
# Source: ingress-nginx/templates/admission-webhooks/validating-webhook.yaml
# before changing this value, check the required kubernetes version
# https://kubernetes.io/docs/reference/access-authn-authz/extensible-admission-controllers/#prerequisites
apiVersion: admissionregistration.k8s.io/v1beta1
kind: ValidatingWebhookConfiguration
metadata:
  labels:
    helm.sh/chart: ingress-nginx-2.13.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.35.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
  name: ingress-nginx-admission
webhooks:
  - name: validate.nginx.ingress.kubernetes.io
    rules:
      - apiGroups:
          - extensions
          - networking.k8s.io
        apiVersions:
          - v1beta1
        operations:
          - CREATE
          - UPDATE
        resources:
          - ingresses
    failurePolicy: Fail
    sideEffects: None
    admissionReviewVersions:
      - v1
      - v1beta1
    clientConfig:
      service:
        namespace: ingress-nginx
        name: ingress-nginx-controller-admission
        path: /extensions/v1beta1/ingresses
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/serviceaccount.yaml
apiVersion: v1
kind: ServiceAccount
metadata:
  name: ingress-nginx-admission
  annotations:
    helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgrade
    helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
  labels:
    helm.sh/chart: ingress-nginx-2.13.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.35.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
  namespace: ingress-nginx
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/clusterrole.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: ingress-nginx-admission
  annotations:
    helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgrade
    helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
  labels:
    helm.sh/chart: ingress-nginx-2.13.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.35.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
rules:
  - apiGroups:
      - admissionregistration.k8s.io
    resources:
      - validatingwebhookconfigurations
    verbs:
      - get
      - update
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/clusterrolebinding.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: ingress-nginx-admission
  annotations:
    helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgrade
    helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
  labels:
    helm.sh/chart: ingress-nginx-2.13.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.35.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: ingress-nginx-admission
subjects:
  - kind: ServiceAccount
    name: ingress-nginx-admission
    namespace: ingress-nginx
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/role.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  name: ingress-nginx-admission
  annotations:
    helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgrade
    helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
  labels:
    helm.sh/chart: ingress-nginx-2.13.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.35.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
  namespace: ingress-nginx
rules:
  - apiGroups:
      - ''
    resources:
      - secrets
    verbs:
      - get
      - create
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/rolebinding.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: ingress-nginx-admission
  annotations:
    helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgrade
    helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
  labels:
    helm.sh/chart: ingress-nginx-2.13.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.35.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
  namespace: ingress-nginx
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: ingress-nginx-admission
subjects:
  - kind: ServiceAccount
    name: ingress-nginx-admission
    namespace: ingress-nginx
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/job-createSecret.yaml
apiVersion: batch/v1
kind: Job
metadata:
  name: ingress-nginx-admission-create
  annotations:
    helm.sh/hook: pre-install,pre-upgrade
    helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
  labels:
    helm.sh/chart: ingress-nginx-2.13.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.35.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
  namespace: ingress-nginx
spec:
  template:
    metadata:
      name: ingress-nginx-admission-create
      labels:
        helm.sh/chart: ingress-nginx-2.13.0
        app.kubernetes.io/name: ingress-nginx
        app.kubernetes.io/instance: ingress-nginx
        app.kubernetes.io/version: 0.35.0
        app.kubernetes.io/managed-by: Helm
        app.kubernetes.io/component: admission-webhook
    spec:
      containers:
        - name: create
          image: docker.io/jettech/kube-webhook-certgen:v1.2.2
          imagePullPolicy: IfNotPresent
          args:
            - create
            - --host=ingress-nginx-controller-admission,ingress-nginx-controller-admission.$(POD_NAMESPACE).svc
            - --namespace=$(POD_NAMESPACE)
            - --secret-name=ingress-nginx-admission
          env:
            - name: POD_NAMESPACE
              valueFrom:
                fieldRef:
                  fieldPath: metadata.namespace
      restartPolicy: OnFailure
      serviceAccountName: ingress-nginx-admission
      securityContext:
        runAsNonRoot: true
        runAsUser: 2000
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/job-patchWebhook.yaml
apiVersion: batch/v1
kind: Job
metadata:
  name: ingress-nginx-admission-patch
  annotations:
    helm.sh/hook: post-install,post-upgrade
    helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
  labels:
    helm.sh/chart: ingress-nginx-2.13.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.35.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
  namespace: ingress-nginx
spec:
  template:
    metadata:
      name: ingress-nginx-admission-patch
      labels:
        helm.sh/chart: ingress-nginx-2.13.0
        app.kubernetes.io/name: ingress-nginx
        app.kubernetes.io/instance: ingress-nginx
        app.kubernetes.io/version: 0.35.0
        app.kubernetes.io/managed-by: Helm
        app.kubernetes.io/component: admission-webhook
    spec:
      containers:
        - name: patch
          image: docker.io/jettech/kube-webhook-certgen:v1.2.2
          imagePullPolicy: IfNotPresent
          args:
            - patch
            - --webhook-name=ingress-nginx-admission
            - --namespace=$(POD_NAMESPACE)
            - --patch-mutating=false
            - --secret-name=ingress-nginx-admission
            - --patch-failure-policy=Fail
          env:
            - name: POD_NAMESPACE
              valueFrom:
                fieldRef:
                  fieldPath: metadata.namespace
      restartPolicy: OnFailure
      serviceAccountName: ingress-nginx-admission
      securityContext:
        runAsNonRoot: true
        runAsUser: 2000
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The installation

[root@t34 ingress-nginx]# kubectl apply -f deploy.yaml 
namespace/ingress-nginx created
serviceaccount/ingress-nginx created
configmap/ingress-nginx-controller created
clusterrole.rbac.authorization.k8s.io/ingress-nginx created
clusterrolebinding.rbac.authorization.k8s.io/ingress-nginx created
role.rbac.authorization.k8s.io/ingress-nginx created
rolebinding.rbac.authorization.k8s.io/ingress-nginx created
service/ingress-nginx-controller-admission created
service/ingress-nginx-controller created
deployment.apps/ingress-nginx-controller created
validatingwebhookconfiguration.admissionregistration.k8s.io/ingress-nginx-admission created
serviceaccount/ingress-nginx-admission created
clusterrole.rbac.authorization.k8s.io/ingress-nginx-admission created
clusterrolebinding.rbac.authorization.k8s.io/ingress-nginx-admission created
role.rbac.authorization.k8s.io/ingress-nginx-admission created
rolebinding.rbac.authorization.k8s.io/ingress-nginx-admission created
job.batch/ingress-nginx-admission-create created
job.batch/ingress-nginx-admission-patch created
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To view

[root@t34 ingress-nginx]# kubectl get pod -n ingress-nginx NAME READY STATUS RESTARTS AGE ingress-nginx-admission-create-jpcb9 0/1 Completed 0 22s ingress-nginx-admission-patch-znpw5 0/1 Completed 1 22s ingress-nginx-controller-744597d577-4tgbf 1/1 Running 0 22s [root@t34 ingress-nginx]# kubectl get svc -n ingress-nginx NAME TYPE cluster-ip external-ip PORT(S) AGE ingress-nginx-controller NodePort 10.43.237.103 <none> 80:31036 / TCP, 443:32012 / TCP 65 s ingress - nginx - controller - admission ClusterIP 10.43.113.189 < none > 443 / TCP 65 sCopy the code

2.2 test

Add the ingress profile

[root@t34 ingress-nginx]# cat example-ingress-nginx.yaml 
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: example-ingress-nginx
  annotations:
    kubernetes.io/ingress.class: nginx 
spec:
  rules:
  - host: example.nginx.com 
    http:
      paths:
      - path: /
        backend:
          serviceName: webapp-svc 
          servicePort: 8000
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test

[root@t34 ingress-nginx]# kubectl apply -f example-ingress-nginx.yaml ingress.networking.k8s.io/example-ingress-nginx created [root@t34 ingress-nginx]# kubectl get ingress NAME HOSTS ADDRESS PORTS AGE example-ingress-nginx Example. Nginx.com 80 5s [root@t34 ingress-nginx]# curl -h "Host: example.nginx.com" 192.168.4.32:31036 user exampleCopy the code

To access webApp services, use the ingress-nginx-controller service (ingress-nginx-controller).

3. ingress-traefik

3.1 the deployment

Yaml files are prepared

apiVersion: v1 kind: ServiceAccount metadata: name: traefik-ingress-controller namespace: kube-system --- kind: ClusterRole apiVersion: rbac.authorization.k8s.io/v1beta1 metadata: name: traefik-ingress-controller rules: - apiGroups: - "" resources: - services - endpoints - secrets verbs: - get - list - watch - apiGroups: - extensions resources: - ingresses verbs: - get - list - watch --- kind: ClusterRoleBinding apiVersion: rbac.authorization.k8s.io/v1beta1 metadata: name: traefik-ingress-controller roleRef: apiGroup: rbac.authorization.k8s.io kind: ClusterRole name: traefik-ingress-controller subjects: - kind: ServiceAccount name: traefik-ingress-controller namespace: kube-system --- kind: Deployment apiVersion: apps/v1 metadata: name: traefik-ingress-controller namespace: kube-system labels: k8s-app: traefik-ingress-lb spec: replicas: 1 selector: matchLabels: k8s-app: traefik-ingress-lb template: metadata: labels: k8s-app: traefik-ingress-lb name: traefik-ingress-lb spec: serviceAccountName: traefik-ingress-controller terminationGracePeriodSeconds: 60 # tolerations: # - operator: "Exists" # nodeSelector: # kubernetes.io/hostname: master containers: - image: Traefik :v1.7.17 Name: traefik-ingress-lb ports: - name: HTTP containerPort: 80 - name: admin containerPort: 8080 args: - --api - --kubernetes - --logLevel=INFO --- kind: Service apiVersion: v1 metadata: name: traefik-ingress-service namespace: kube-system spec: selector: k8s-app: traefik-ingress-lb ports: - protocol: TCP port: 80 name: web - protocol: TCP port: 8080 name: admin type: NodePortCopy the code

The installation

[root@t34 k8s]# kubectl apply -f ingress-traefik/
ingress.networking.k8s.io/example-ingress-traefik created
serviceaccount/traefik-ingress-controller created
clusterrole.rbac.authorization.k8s.io/traefik-ingress-controller created
clusterrolebinding.rbac.authorization.k8s.io/traefik-ingress-controller created
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To view

[root@t34 k8s]# kubectl get pod -n kube-system |grep traefik traefik-ingress-controller-658698fc8-9ghsl 1/1 Running 0 42 [root s @ t34 k8s] # kubectl kube get SVC - n - system | grep traefik traefik ingress - service NodePort 10.43.184.34 < none > 80:30776/TCP,8080:31812/TCP 48s [root@t34 k8s]#Copy the code

3.2 test

Add the ingress profile

[root@t34 ingress-traefik]# cat example-ingress-traefik.yaml 
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: example-ingress-traefik
  annotations:
    kubernetes.io/ingress.class: traefik
spec:
  rules:
  - host: example.traefik.com
    http:
      paths:
      - path: /
        backend:
          serviceName: webapp-svc 
          servicePort: 8000
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test

[root@t34 ingress-traefik]# kubectl apply -f example-ingress-traefik.yaml ingress.networking.k8s.io/example-ingress-traefik created [root@t34 ingress-traefik]# kubectl get ingress NAME HOSTS ADDRESS PORTS AGE examples-ingress-nginx example.nginx.com 192.168.4.91 80 10m examples-ingress-traefik example.traefik.com 80 7s [root@t34 ingress-traefik]# curl -H "Host: Example.traefik.com "192.168.4.34:30776 user exampleCopy the code

4. Conclusion

K8s is a powerful tool in the era of micro services. It is crucial to master the flow direction of each service flow. How does the client flow to the server? How are internal services accessed? How to choose clusterip under different scenarios, nodeport, ingress, gateway, etc? It is essential that you know how to do things like DNS resolution.

How to access k8S internal service -ingress

1. The background

2. ingress-nginx

2.1 the deployment

2.2 test

3. ingress-traefik

3.1 the deployment

3.2 test

4. Conclusion

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