[K8s] Ingress 개념 및 Ingress Controller 설치, 활용

Ingress API란?

• HTTP나 HTTPS를 통해 클러스터 내부의 서비스를 외부로 노출
• 기능
  • Service에 외부 URL을 제공
  • 트래픽을 로드밸런싱
  • SSL 인증서 처리
  • Virtural hosting을 지정

 

Ingress controller 동작 방식

<이미지 출처 : [따배쿠] 8-1 Kubernetes Ingress 개념과 Ingress Controller 설치! >

 

Nginx Ingress controller 설치

• Installation Guide - NGINX Ingress Controller 참고

kubectl apply -f <https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v1.2.0/deploy/static/provider/baremetal/deploy.yaml>

• 설치 확인

kubectl get pod --namespace ingress-nginx

NAME                                        READY   STATUS      RESTARTS   AGE
ingress-nginx-admission-create-qxcsn        0/1     Completed   0          99s
ingress-nginx-admission-patch-zw5bb         0/1     Completed   1          99s
ingress-nginx-controller-6b864cf6dd-rtr6l   1/1     Running     0          99s

kubectl get service --namespace ingress-nginx

NAME                                 TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)                      AGE
ingress-nginx-controller             NodePort    10.111.64.176    <none>        80:32337/TCP,443:30606/TCP   2m7s
ingress-nginx-controller-admission   ClusterIP   10.106.201.197   <none>        443/TCP                      2m7s

 

[ Hands - on ] : 웹페이지 구현하기

• Installation Guide - NGINX Ingress Controller 에서 nginx ingress controller yaml 파일 다운로드

curl <https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v1.2.0/deploy/static/provider/baremetal/deploy.yaml>

• nodeport 수정
  • 외부에서 loadbalancer로 port-forwarding 하기 위해서는 고정된 port를 사용해야 함.

vi depoly.yaml

...
apiVersion: v1
kind: Service
metadata:
  labels:
    app.kubernetes.io/component: controller
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
    app.kubernetes.io/version: 1.2.0
  name: ingress-nginx-controller
  namespace: ingress-nginx
spec:
  ports:
  - appProtocol: http
    name: http
    port: 80
    protocol: TCP
    targetPort: http
    nodePort: 30100           #nodeport 지정
  - appProtocol: https
    name: https
    port: 443
    protocol: TCP
    targetPort: https
    nodePort: 30200           #nodeport 지정
  selector:
    app.kubernetes.io/component: controller
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/name: ingress-nginx
  type: NodePort
...

• 생성 확인

kubectl get all --namespace ingress-nginx

NAME                                            READY   STATUS      RESTARTS   AGE
pod/ingress-nginx-admission-create-zpn8p        0/1     Completed   0          58s
pod/ingress-nginx-admission-patch-p9cc8         0/1     Completed   1          58s
pod/ingress-nginx-controller-6b864cf6dd-vcssn   1/1     Running     0          58s

NAME                                         TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)                      AGE
service/ingress-nginx-controller             NodePort    10.98.3.126      <none>        80:30100/TCP,443:30200/TCP   58s
service/ingress-nginx-controller-admission   ClusterIP   10.111.157.100   <none>        443/TCP                      58s

NAME                                       READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/ingress-nginx-controller   1/1     1            1           58s

NAME                                                  DESIRED   CURRENT   READY   AGE
replicaset.apps/ingress-nginx-controller-6b864cf6dd   1         1         1       58s

NAME                                       COMPLETIONS   DURATION   AGE
job.batch/ingress-nginx-admission-create   1/1           7s         58s
job.batch/ingress-nginx-admission-patch    1/1           6s         58s

• default namespace를 변경하기 위한 context 추가

kubectl config set-context ingres-admin@kubernetes --cluster=kubernetes --user=kubernetes-admin --namespace ingress-nginx

• context 확인

kubectl config view

apiVersion: v1
clusters:
- cluster:
    certificate-authority-data: DATA+OMITTED
    server: <https://10.100.0.104:6443>
  name: kubernetes
contexts:
- context:
    cluster: kubernetes
    namespace: ingress-nginx
    user: kubernetes-admin
  name: ingres-admin@kubernetes
- context:
    cluster: kubernetes
    user: kubernetes-admin
  name: kubernetes-admin@kubernetes
current-context: kubernetes-admin@kubernetes
kind: Config
preferences: {}
users:
- name: kubernetes-admin
  user:
    client-certificate-data: REDACTED
    client-key-data: REDACTED

• default namespace 변경 및 확인

kubectl config use-context ingres-admin@kubernetes

kubectl get pod

NAME                                        READY   STATUS      RESTARTS   AGE
ingress-nginx-admission-create-zpn8p        0/1     Completed   0          74m
ingress-nginx-admission-patch-p9cc8         0/1     Completed   1          74m
ingress-nginx-controller-6b864cf6dd-vcssn   1/1     Running     0          74m

• web service 실행

vi marvel-home.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: marvel-home
spec:
  replicas: 1
  selector:
    matchLabels:
      name: marvel
  template:
    metadata:
      labels:
        name: marvel
    spec:
      containers:
      - image: smlinux/marvel-collection
        name: marvel-container
        ports:
        - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: marvel-service
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    name: marvel

vi pay.yaml

apiVersion: v1
kind: ReplicationController
metadata:
  name: pay-rc
spec:
  replicas: 3
  template:
    metadata:
      labels:
        app: pay
    spec:
      containers:
      - image: smlinux/pay
        name: pay
        ports:
        - containerPort: 8080
---
apiVersion: v1
kind: Service
metadata:
  name: pay-service
spec:
  ports:
  - port: 80
    targetPort: 8080
  selector:
    app: pay

kubectl create -f marvel-home.yaml -f pay.yaml

• web service 확인

kubectl get all

NAME                                            READY   STATUS      RESTARTS   AGE
pod/ingress-nginx-admission-create-zpn8p        0/1     Completed   0          87m
pod/ingress-nginx-admission-patch-p9cc8         0/1     Completed   1          87m
pod/ingress-nginx-controller-6b864cf6dd-vcssn   1/1     Running     0          87m
pod/marvel-home-8595d4c47d-wj6t4                1/1     Running     0          34s
pod/pay-rc-5vtzx                                1/1     Running     0          34s
pod/pay-rc-8w5dg                                1/1     Running     0          34s
pod/pay-rc-nc4ft                                1/1     Running     0          34s

NAME                           DESIRED   CURRENT   READY   AGE
replicationcontroller/pay-rc   3         3         3       34s

NAME                                         TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)                      AGE
service/ingress-nginx-controller             NodePort    10.98.3.126      <none>        80:30100/TCP,443:30200/TCP   87m
service/ingress-nginx-controller-admission   ClusterIP   10.111.157.100   <none>        443/TCP                      87m
service/marvel-service                       ClusterIP   10.99.6.151      <none>        80/TCP                       34s
service/pay-service                          ClusterIP   10.100.200.245   <none>        80/TCP                       34s

NAME                                       READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/ingress-nginx-controller   1/1     1            1           87m
deployment.apps/marvel-home                1/1     1            1           34s

NAME                                                  DESIRED   CURRENT   READY   AGE
replicaset.apps/ingress-nginx-controller-6b864cf6dd   1         1         1       87m
replicaset.apps/marvel-home-8595d4c47d                1         1         1       34s

NAME                                       COMPLETIONS   DURATION   AGE
job.batch/ingress-nginx-admission-create   1/1           7s         87m
job.batch/ingress-nginx-admission-patch    1/1           6s         87m

• Ingress 구성

vi ingress.yaml

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

kubectl create -f ingress.yaml

• Ingress 확인

kubectl describe ingress marvel-ingress

NAME             CLASS    HOSTS   ADDRESS   PORTS   AGE
marvel-ingress   <none>   *                 80      66s
root@master:~/Getting-Start-Kubernetes/8/webserver-demo/ingress# kubectl describe ingress marvel-ingress
Name:             marvel-ingress
Labels:           <none>
Namespace:        ingress-nginx
Address:
Ingress Class:    <none>
Default backend:  <default>
Rules:
  Host        Path  Backends
  ----        ----  --------
  *
              /      marvel-service:80 (192.168.11.77:80)
              /pay   pay-service:80 (192.168.11.78:8080,192.168.11.79:8080,192.168.221.15:8080)
Annotations:  <none>
Events:       <none>

• web service 접속

curl 10.98.3.126

curl 10.98.3.126/pay

 

 

참고 :

[따배쿠] 8-1 Kubernetes Ingress 개념과 Ingress Controller 설치!