【Kubernetes实战】（十七）Ingress 控制器

小灰灰 2024-03-24 08:40 51阅读 0赞

## 一、环境安装 ##

参考

[【Kubernetes实战】（四）MiniKube方式部署][Kubernetes_MiniKube]

[【Kubernetes实战】（五）KubeAdm方式部署][Kubernetes_KubeAdm]

[【Kubernetes实战】（六）Kind方式部署][Kubernetes_Kind]

## 二、Ingress介绍 ##

### 1 基本概念 ###

`Ingress`相当于一个`7`层的负载均衡器，是`Kubernetes`对反向代理的一个抽象，它的工作原理类似于`Nginx`，可以理解成在\*\* Ingress 里建立诸多映射规则，Ingress Controller 通过监听这些配置规则并转化成 Nginx 的反向代理配置，然后对外部提供服务\*\*。

两个核心概念：

*  `Ingress`：`Kubernetes`中的一个对象，作用是定义请求如何转发到`Service`的规则
 *  `Ingress Controller`：具体实现反向代理及负载均衡的程序，对`Ingress`定义的规则进行解析，根据配置的规则来实现请求转发，实现方式有很多，比如`Nginx`，`Contour`，`Haproxy`等

### 2 工作原理 ###

1.  用户编写`Ingress`规则，说明哪个域名对应`Kubernetes`集群中的哪个`Service`
2.  `Ingress`控制器动态感知`Ingress`服务规则的变化，然后生成一段对应的`Nginx`反向代理配置
3.  `Ingress`控制器会将生成的`Nginx`配置写入到一个运行着的`Nginx`服务中，并动态更新

查看Ingress官方帮助

kubectl explain ingress

KIND:     Ingress
    VERSION:  networking.k8s.io/v1
    
    DESCRIPTION:
         Ingress is a collection of rules that allow inbound connections to reach
         the endpoints defined by a backend. An Ingress can be configured to give
         services externally-reachable urls, load balance traffic, terminate SSL,
         offer name based virtual hosting etc.
    
    FIELDS:
       apiVersion   <string>
         APIVersion defines the versioned schema of this representation of an
         object. Servers should convert recognized schemas to the latest internal
         value, and may reject unrecognized values. More info:
         https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#resources
    
       kind <string>
         Kind is a string value representing the REST resource this object
         represents. Servers may infer this from the endpoint the client submits
         requests to. Cannot be updated. In CamelCase. More info:
         https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds
    
       metadata     <Object>
         Standard object's metadata. More info:
         https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata
    
       spec <Object>
         Spec is the desired state of the Ingress. More info:
         https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#spec-and-status
    
       status       <Object>
         Status is the current state of the Ingress. More info:
         https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#spec-and-status

## 三、Ingress使用 ##

### 1 创建yml文件 ###

tomcat-nginx.yml

apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: nginx-deployment
      namespace: dev
    spec:
      replicas: 3
      selector:
        matchLabels:
          app: nginx-pod
      template:
        metadata:
          labels:
            app: nginx-pod
        spec:
          containers:
          - name: nginx
            image: nginx:1.17.1
            ports:
            - containerPort: 80
    
    ---
    
    apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: tomcat-deployment
      namespace: dev
    spec:
      replicas: 3
      selector:
        matchLabels:
          app: tomcat-pod
      template:
        metadata:
          labels:
            app: tomcat-pod
        spec:
          containers:
          - name: tomcat
            image: tomcat:8.5-jre10-slim
            ports:
            - containerPort: 8080
    
    ---
    
    apiVersion: v1
    kind: Service
    metadata:
      name: nginx-service
      namespace: dev
    spec:
      selector:
        app: nginx-pod
      clusterIP: None
      type: ClusterIP
      ports:
      - port: 80
        targetPort: 80
    
    ---
    
    apiVersion: v1
    kind: Service
    metadata:
      name: tomcat-service
      namespace: dev
    spec:
      selector:
        app: tomcat-pod
      clusterIP: None
      type: ClusterIP
      ports:
      - port: 8080
        targetPort: 8080

### 2 创建service和deploy实例 ###

kubectl create -f tomcat-nginx.yml

![efbfa66ac943434babfde48e69e49213.png][]

### 3 查看service服务 ###

kubectl get svc -n dev

![b6c573e686bd47dc9f748a08903bac8e.png][]

### 4 创建Ingress HTTP 代理 ###

ingress-http.yml

apiVersion: networking.k8s.io/v1
    kind: Ingress
    metadata:
      name: ingress-http
      namespace: dev
    spec:
      rules:
      - host: nginx.example.com
        http:
          paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: nginx-service # svc 中配置的名字
                port: 
                  number: 80 # svc 中配置的端口
      - host: tomcat.example.com
        http:
          paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: tomcat-service
                port: 
                  number: 8080

kubectl create -f ingress-http.yml

![ed2ad5c44ce7459389c54fb298f9252b.png][]

###  ###

### 5 查看 Ingress ###

kubectl get ing -n dev

![85505f70fb774f5d8475f0c35d70ca9b.png][]

###  ###

[Kubernetes_MiniKube]: https://blog.csdn.net/forest_long/article/details/129665163
[Kubernetes_KubeAdm]: https://blog.csdn.net/forest_long/article/details/129665224
[Kubernetes_Kind]: https://blog.csdn.net/forest_long/article/details/129665231
[efbfa66ac943434babfde48e69e49213.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/24/e3dfaffb8d134a9fbb295094158d2e74.png
[b6c573e686bd47dc9f748a08903bac8e.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/24/0a761c9c814c4536aa722bc2c0c37fcd.png
[ed2ad5c44ce7459389c54fb298f9252b.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/24/e0b722c48fc04f47ae11b6c61e2a99fa.png
[85505f70fb774f5d8475f0c35d70ca9b.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/24/e8954c1af80549a0a33f257c7dc3c327.png