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企业项目实战k8s篇（八）Ingress服务

2021-07-29 12:32:39 作者：互联网

Ingress服务

一.Ingress服务简介
二.ingress部署
三.域名访问+ingeress-nginx

一.Ingress服务简介

一种全局的、为了代理不同后端 Service 而设置的负载均衡服务，就是 Kubernetes 里的Ingress 服务。
Ingress由两部分组成：Ingress controller和Ingress服务。
Ingress Controller 会根据你定义的 Ingress 对象，提供对应的代理能力。业界常用的各种反向代理项目，比如 Nginx、HAProxy、Envoy、Traefik 等，都已经为Kubernetes 专门维护了对应的 Ingress Controller。
ingress服务的使用必须在策略网络中才能实现，如calico网络

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ingress相当于一个7层的负载均衡器，是k8s对反向代理的一个抽象。大概的工作原理也确实类似于Nginx，可以理解成在 Ingress 里建立一个个映射规则 , ingress Controller 通过监听 Ingress这个api对象里的配置规则并转化成 Nginx 的配置（kubernetes声明式API和控制循环） , 然后对外部提供服务。ingress包括：ingress controller和ingress resources

ingress controller：核心是一个deployment，实现方式有很多，比如nginx, Contour, Haproxy, trafik, Istio，需要编写的yaml有：Deployment, Service, ConfigMap, ServiceAccount（Auth），其中service的类型可以是NodePort或者LoadBalancer。

ingress resources：这个就是一个类型为Ingress的k8s api对象了，这部分则是面向开发人员。

二.ingress部署

官网下载镜像及安装文件，将镜像上传至集群使用的harbor仓库
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执行安装脚本

kubectl apply -f deploy.yaml

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查看ingress服务，部署成功

[root@server1 ingress]# kubectl  -n ingress-nginx  get svc
NAME                                 TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)                      AGE
ingress-nginx-controller             NodePort    10.104.84.227    <none>        80:31015/TCP,443:32169/TCP   16h
ingress-nginx-controller-admission   ClusterIP   10.106.177.206   <none>        443/TCP                      16h

三.域名访问+ingeress-nginx

修改ingress-nginx-controller配置
type: LoadBalancer

[root@server1 ingress]# kubectl  -n ingress-nginx  edit svc ingress-nginx-controller
service/ingress-nginx-controller edited

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可以看到loadbalancer分配ip 172.25.3.10

[root@server1 ingress]# kubectl  -n ingress-nginx  get svc
NAME                                 TYPE           CLUSTER-IP       EXTERNAL-IP   PORT(S)                      AGE
ingress-nginx-controller             LoadBalancer   10.104.84.227    172.25.3.10   80:31015/TCP,443:32169/TCP   16h
ingress-nginx-controller-admission   ClusterIP      10.106.177.206   <none>        443/TCP                      16h

创建pod：nginx myapp

[root@server1 ~]# cat  deployment.yml 
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: myapp:v1
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp-deployment
  labels:
    app: myapp
spec:
  replicas: 3
  selector:
    matchLabels:
      app: myapp
  template:
    metadata:
      labels:
        app: myapp
    spec:
      containers:
      - name: myapp
        image: myapp:v2

查看pod

[root@server1 ~]# kubectl  get pod
NAME                                READY   STATUS    RESTARTS   AGE
myapp-deployment-67f8c948cf-45h6n   1/1     Running   0          105m
myapp-deployment-67f8c948cf-hq9xg   1/1     Running   0          105m
myapp-deployment-67f8c948cf-rr9bz   1/1     Running   0          105m
nginx-deployment-6456d7c676-8jsrd   1/1     Running   2          19h
nginx-deployment-6456d7c676-bcx9b   1/1     Running   2          19h
nginx-deployment-6456d7c676-kwqfr   1/1     Running   2          19h

创建service

[root@server1 ~]# cat svc.yml 
apiVersion: v1
kind: Service
metadata:
  name: nginx-svc
spec:
  ports:
  - protocol: TCP
    port: 80
    targetPort: 80
  selector:
    app: nginx
---
apiVersion: v1
kind: Service
metadata:
  name: myapp-svc
spec:
  ports:
  - protocol: TCP
    port: 80
    targetPort: 80
  selector:
    app: myapp

查看service

[root@server1 ~]# kubectl  get svc
NAME         TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)   AGE
kubernetes   ClusterIP   10.96.0.1       <none>        443/TCP   4d18h
myapp-svc    ClusterIP   10.109.211.64   <none>        80/TCP    124m
nginx-svc    ClusterIP   10.103.119.38   <none>        80/TCP    124m

ingress.yml下赋予域名匹配，用于匹配service

[root@server1 ingress]# cat ingress.yml 
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: ingress-nginx
spec:
  rules:
  - host: www1.westos.org
    http:
      paths:
      - path: /
        backend:
          serviceName: nginx-svc
          servicePort: 80
---
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: ingress-myapp
spec:
  rules:
  - host: www2.westos.org
    http:
      paths:
      - path: /
        backend:
          serviceName: myapp-svc
          servicePort: 80

查看ingress信息

[root@server1 ingress]# kubectl  get ingress
NAME            CLASS    HOSTS             ADDRESS      PORTS   AGE
ingress-myapp   <none>   www2.westos.org   172.25.3.2   80      117m
ingress-nginx   <none>   www1.westos.org   172.25.3.2   80      117m

设置本地解析

vim /etc/hosts

172.25.3.10  www1.westos.org www2.westos.org

域名访问测试,访问到对应service

[root@server1 ingress]# curl  www2.westos.org
Hello MyApp | Version: v2 | <a href="hostname.html">Pod Name</a>
[root@server1 ingress]# curl  www1.westos.org
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>

负载均衡测试，成功 myapp-svc

[root@server1 ingress]# curl www1.westos.org/hostname.html
nginx-deployment-6456d7c676-8jsrd
[root@server1 ingress]# curl www1.westos.org/hostname.html
nginx-deployment-6456d7c676-8jsrd
[root@server1 ingress]# curl www1.westos.org/hostname.html
nginx-deployment-6456d7c676-bcx9b
[root@server1 ingress]# curl www1.westos.org/hostname.html
nginx-deployment-6456d7c676-kwqfr
[root@server1 ingress]# curl www1.westos.org/hostname.html
nginx-deployment-6456d7c676-bcx9b

查看详细内容，可以看到www2.westos.org 对应 nginx-svc:80，nginx-svc下有三个pod 的ip用于均衡访问

 kubectl  describe  ingress ingress-nginx

[root@server1 ingress]#  kubectl  describe  ingress ingress-nginx 
Name:             ingress-nginx
Namespace:        default
Address:          172.25.3.2
Default backend:  default-http-backend:80 (<error: endpoints "default-http-backend" not found>)
Rules:
  Host             Path  Backends
  ----             ----  --------
  www1.westos.org  
                   /   nginx-svc:80 (10.244.179.71:80,10.244.179.72:80,10.244.22.6:80)
Annotations:       <none>
Events:            <none>

标签：实战,Ingress,ingress,server1,nginx,myapp,80,k8s,root
来源： https://blog.csdn.net/qq_42003848/article/details/119206534