BoyChai's Blog - ingress
https://blog.boychai.xyz/index.php/tag/ingress/
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Kubernetes-容器编排引擎(Ingress-nginx)
https://blog.boychai.xyz/index.php/archives/29/
2022-09-06T09:19:00+00:00
Ingress概述Service对集群之外暴露服务的主要方式有两种：NotePort和LoadBalancer，但是这两种方式，都有一定的缺点：NodePort方式的缺点是会占用很多集群机器的端口，那么当集群服务变多的时候，这个缺点就愈发明显LB方式的缺点是每个service需要一个LB，浪费、麻烦，并且需要kubernetes之外设备的支持基于这种现状，kubernetes提供了Ingress资源对象，Ingress只需要一个NodePort或者一个LB就可以满足暴露多个Service的需求。工作机制大致如下图表示：实际上，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。在这里有两个核心概念：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等等Ingress（以Nginx为例）的工作原理如下：用户编写Ingress规则，说明哪个域名对应kubernetes集群中的哪个ServiceIngress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，并动态更新到此为止，其实真正在工作的就是一个Nginx了，内部配置了用户定义的请求转发规则Ingress使用环境配置环境为3个deploy，分别部署3个pod，镜像依次为nginx，apache，tomcat，并对应部署了三个service创建文件Ingress-Env.yaml，内容如下---
apiVersion: apps/v1
kind: Deployment
metadata:
name: ingress-env-nginx
namespace: default
spec:
replicas: 3
selector:
matchLabels:
ingress-env: nginx-pod
template:
metadata:
labels:
ingress-env: nginx-pod
spec:
containers:
- name: nginx
image: docker.io/library/nginx:1.23.1
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: ingress-env-httpd
namespace: default
spec:
replicas: 3
selector:
matchLabels:
ingress-env: httpd-pod
template:
metadata:
labels:
ingress-env: httpd-pod
spec:
containers:
- name: httpd
image: docker.io/library/httpd:2.4.54
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: ingress-env-tomcat
namespace: default
spec:
replicas: 3
selector:
matchLabels:
ingress-env: tomcat-pod
template:
metadata:
labels:
ingress-env: tomcat-pod
spec:
containers:
- name: tomcat
image: docker.io/library/tomcat:8.5-jre10-slim
---
apiVersion: v1
kind: Service
metadata:
name: ingress-env-nginx-svc
namespace: default
spec:
selector:
ingress-env: nginx-pod
clusterIP: 10.97.2.1 # service的ip地址，如果不写，默认会生成一个
type: ClusterIP
ports:
- port: 80 # Service端口
targetPort: 80 # pod端口
---
apiVersion: v1
kind: Service
metadata:
name: ingress-env-httpd-svc
namespace: default
spec:
selector:
ingress-env: httpd-pod
clusterIP: 10.97.2.2 # service的ip地址，如果不写，默认会生成一个
type: ClusterIP
ports:
- port: 80 # Service端口
targetPort: 80 # pod端口
---
apiVersion: v1
kind: Service
metadata:
name: ingress-env-tomcat-svc
namespace: default
spec:
selector:
ingress-env: tomcat-pod
clusterIP: 10.97.2.3 # service的ip地址，如果不写，默认会生成一个
type: ClusterIP
ports:
- port: 80 # Service端口
targetPort: 8080 # pod端口
# 创建环境
[root@master yaml]# kubectl create -f Ingress-Env.yaml
deployment.apps/ingress-env-nginx created
deployment.apps/ingress-env-httpd created
deployment.apps/ingress-env-tomcat created
service/ingress-env-nginx-svc created
service/ingress-env-httpd-svc created
service/ingress-env-tomcat-svc created
# 查看Pod
[root@master yaml]# kubectl get pod -n default
NAME READY STATUS RESTARTS AGE
ingress-env-httpd-59b9f557c4-gjvhn 1/1 Running 0 15s
ingress-env-httpd-59b9f557c4-j6q9b 1/1 Running 0 15s
ingress-env-httpd-59b9f557c4-zp9fv 1/1 Running 0 15s
ingress-env-nginx-7d899c7648-4r7gx 1/1 Running 0 15s
ingress-env-nginx-7d899c7648-6fzq9 1/1 Running 0 15s
ingress-env-nginx-7d899c7648-stv77 1/1 Running 0 15s
ingress-env-tomcat-679896868f-27zhq 1/1 Running 0 15s
ingress-env-tomcat-679896868f-w9gd6 1/1 Running 0 15s
ingress-env-tomcat-679896868f-wwwnn 1/1 Running 0 15s
# 查看deploy
[root@master yaml]# kubectl get deploy -n default
NAME READY UP-TO-DATE AVAILABLE AGE
ingress-env-httpd 3/3 3 3 31s
ingress-env-nginx 3/3 3 3 31s
ingress-env-tomcat 3/3 3 3 31s
# 查看svc
[root@master yaml]# kubectl get svc -n default
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
ingress-env-httpd-svc ClusterIP 10.97.2.2 <none> 80/TCP 44s
ingress-env-nginx-svc ClusterIP 10.97.2.1 <none> 80/TCP 44s
ingress-env-tomcat-svc ClusterIP 10.97.2.3 <none> 80/TCP 44s
# 测试svc
# 都有页面返回即可
[root@master yaml]# curl 10.97.2.1
......
<h1>Welcome to nginx!</h1>
......
[root@master yaml]# curl 10.97.2.2
<html><body><h1>It works!</h1></body></html>
[root@master yaml]# curl 10.97.2.3
......
<h2>If you're seeing this, you've successfully installed Tomcat. Congratulations!</h2>
......Ingress-nginx安装# 下载Ingress的部署资源清单
# 我这里的版本是v1.3.0
[root@master yaml]# curl -o Ingress-Deploy.yaml https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v1.3.0/deploy/static/provider/cloud/deploy.yaml
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 15490 100 15490 0 0 15694 0 --:--:-- --:--:-- --:--:-- 15678
# 替换镜像
# Ingress-Deploy里面会用到两个镜像
# 一个是ingress-nginx/controller:1.3.0还有一个是ingress-nginx-kube-webhook-certgen:v1.1.1
# 默认都是从k8s镜像仓库下载的,都被墙了,需要把这两个修改为其他的，这里我自己科学上网pull下来放到仓库了修改内容如下
# 注意一共有三个镜像配置，有两个kube-webhook-certgen，三个都要改
image: registry.k8s.io/ingress-nginx/controller:v1.3.0... > image: docker.io/boychai/ingress-nginx-controlle:v1.3.0
image
image: registry.k8s.io/ingress-nginx/kube-webhook-certgen:v1.1.1... > image: docker.io/boychai/ingress-nginx-kube-webhook-certgen:v1.1.1
# 添加hostNetwork配置
# 在Ingress-Deploy的里面会有段Deployment的配置大概在388行
# 在Deployment.spec.template.spec添加hostNetwork:true
......
412 spec:
413 hostNetwork: true
414 containers:
415 - args:
416 - /nginx-ingress-controller
417 - --publish-service=$(POD_NAMESPACE)/ingress-nginx-controller
......
# 创建Ingress-Nginx
[root@master yaml]# kubectl create -f Ingress-Deploy.yaml
namespace/ingress-nginx created
serviceaccount/ingress-nginx created
serviceaccount/ingress-nginx-admission created
role.rbac.authorization.k8s.io/ingress-nginx created
role.rbac.authorization.k8s.io/ingress-nginx-admission created
clusterrole.rbac.authorization.k8s.io/ingress-nginx created
clusterrole.rbac.authorization.k8s.io/ingress-nginx-admission created
rolebinding.rbac.authorization.k8s.io/ingress-nginx created
rolebinding.rbac.authorization.k8s.io/ingress-nginx-admission created
clusterrolebinding.rbac.authorization.k8s.io/ingress-nginx created
clusterrolebinding.rbac.authorization.k8s.io/ingress-nginx-admission created
configmap/ingress-nginx-controller created
service/ingress-nginx-controller created
service/ingress-nginx-controller-admission created
deployment.apps/ingress-nginx-controller created
job.batch/ingress-nginx-admission-create created
job.batch/ingress-nginx-admission-patch created
ingressclass.networking.k8s.io/nginx created
validatingwebhookconfiguration.admissionregistration.k8s.io/ingress-nginx-admission created
# 查看pod
[root@master yaml]# kubectl get pod -n ingress-nginx
NAME READY STATUS RESTARTS AGE
ingress-nginx-admission-create-69hcz 0/1 Completed 0 50s
ingress-nginx-admission-patch-pwm7c 0/1 Completed 0 49s
ingress-nginx-controller-7fc79df64f-tcx85 1/1 Running 0 50s
# 查看service
[root@master yaml]# kubectl get svc -n ingress-nginx
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
ingress-nginx-controller LoadBalancer 10.104.11.86 <pending> 80:32637/TCP,443:31430/TCP 80s
ingress-nginx-controller-admission ClusterIP 10.99.43.141 <none> 443/TCP 80s
Ingress-nginx使用ingress可以代理http和https，如果要使用https需要导入证书相关文件到secret，操作如下# 创建tls目录并生成私钥和证书
[root@master yaml]# mkdir tls
[root@master tls]# openssl req -x509 -sha256 -nodes -days 365 -newkey rsa:2048 -keyout tls.key -out tls.crt -subj "/C=CN/ST=QD/L=QD/O=nginx/CN=host.com"
Generating a RSA private key
.....+++++
................................+++++
writing new private key to 'tls.key'
-----
[root@master tls]# ls
tls.crt tls.key
# 导入到secret
[root@master tls]# kubectl create secret tls tls-secret --key tls.key --cert tls.crt
secret/tls-secret created
# 查看secret
[root@master tls]# kubectl get secret
NAME TYPE DATA AGE
tls-secret kubernetes.io/tls 2 75s创建Ingress-Basic.yaml，内容如下apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: ingress-basic
spec:
tls:
- hosts:
- nginx.host.com
- apache.host.com
- tomcat.host.com
secretName: tls.secret # 指定证书配
ingressClassName: nginx
rules:
- host: "nginx.host.com"
http:
paths:
- pathType: Prefix
path: /
backend:
service:
name: ingress-env-nginx-svc
port:
number: 80
- host: "apache.host.com"
http:
paths:
- pathType: Prefix
path: /
backend:
service:
name: ingress-env-httpd-svc
port:
number: 80
- host: "tomcat.host.com"
http:
paths:
- pathType: Prefix
path: /
backend:
service:
name: ingress-env-tomcat-svc
port:
number: 80# 创建Ingres
[root@master yaml]# kubectl create -f Ingress-Basic.yaml
ingress.networking.k8s.io/ingress-basic created
# 查看Ingress
[root@master yaml]# kubectl get Ingress -n default
NAME CLASS HOSTS ADDRESS PORTS AGE
ingress-basic nginx nginx.host.com,apache.host.com,tomcat.host.com 80, 443 12s
# 查看Ingress详情
[root@master yaml]# kubectl describe Ingress ingress-basic -n default
......
TLS:
tls.secret terminates apache.host.com,tomcat.host.com
Rules:
Host Path Backends
---- ---- --------
nginx.host.com
/ ingress-env-nginx-svc:80 (10.244.52.248:80,10.244.67.124:80,10.244.67.80:80)
apache.host.com
/ ingress-env-httpd-svc:80 (10.244.52.238:80,10.244.67.114:80,10.244.67.75:80)
tomcat.host.com
/ ingress-env-tomcat-svc:80 (10.244.52.229:8080,10.244.67.103:8080,10.244.67.70:8080)
......
# 访问测试
# 当域名[nginx,apache,tomcat].host.com解析到work节点之后去访问即可
# master我没有消除污点也没有配置ingres的容忍所以只能访问work节点
[root@master yaml]# curl -k --tlsv1 https://nginx.host.com
......
<h1>Welcome to nginx!</h1>
......
[root@master yaml]# curl -k --tlsv1 https://apache.host.com
<html><body><h1>It works!</h1></body></html>
[root@master yaml]# curl -k --tlsv1 https://tomcat.host.com
......
<h2>If you're seeing this, you've successfully installed Tomcat. Congratulations!</h2>
......http代理上面的配置是https的代理，如果要用http的话把tls段全部删掉就可以了