解决项目迁移至Kubernetes集群中的代理问题

随着Kubernetes技术的日益成熟，越来越多的企业选择用Kubernetes集群来管理项目。新项目还好，可以选择合适的集群规模从零开始构建项目；旧项目迁移进Kubernetes集群就需要考虑很多因素，毕竟项目不能中断时间过久。

问题来源

近日在做项目迁移至Kubernetes集群时，遇到了一件有意思的问题：因为开发用的dubbo版本过低，在zookeeper注册不上，需要开发升级dobbo，然后在打包成镜像，所以要先把nodejs迁移进Kubernets集群。因为是部分业务迁移进Kubernets集群，所以要在traefik 前面还得加一层代理Nginx(Nginx为旧业务的入口，反向代理后面的微服务，阿里云的slb指向nginx，等到业务全部迁移完毕，slb就指向traefik)。此种架构为双层代理，即Slb-->Nginx-->Traefik-->Service 。

图解

解决方案：

迁移至k8s集群的业务走Nodeport，Nginx --> Nodeport。业务应用直接Nodeport，不好管理，1万台机器的时候不能也Nodeport吧，端口自己要规划，机器多了每个机器还都暴露端口，想想都不现实
迁移至k8s集群的业务走Clusterip，Nginx --> Traefik --> Service。这种方式合理。

解决问题

总不能拿生产环境来写博文吧，用虚机讲明。其实把虚机和生产机也就网络环境存在差别。

思路分析

部署k8s集群
部署nginx
部署traefik
部署应用
联调联试

部署k8s集群

使用我之前的博文部署方法：https://www.cnblogs.com/zisefeizhu/p/12505117.html

部署nginx

下载必要的组件

# hostname -I
20.0.0.101
# cat /etc/redhat-release 
CentOS Linux release 7.6.1810 (Core) 
# uname -a
Linux fuxi-node02-101 4.4.186-1.el7.elrepo.x86_64 #1 SMP Sun Jul 21 04:06:52 EDT 2019 x86_64 x86_64 x86_64 GNU/Linux
# wget http://nginx.org/download/nginx-1.10.2.tar.gz
# wget http://www.openssl.org/source/openssl-fips-2.0.10.tar.gz
# wget http://zlib.net/zlib-1.2.11.tar.gz
# wget https://ftp.pcre.org/pub/pcre/pcre-8.40.tar.gz
# yum install gcc-c++

配置-编译-安装软件

# tar zxvf openssl-fips-2.0.10.tar.gz
# cd openssl-fips-2.0.10/
# ./config && make && make install
# cd ..
# ll
tar zxvf pcre-8.40.tar.gz
# cd pcre-8.40/
# ./configure && make && make install
# tar zxvf zlib-1.2.11.tar.gz
# cd zlib-1.2.11/
# ./configure && make && make install
# tar zxvf nginx-1.10.2.tar.gz
# cd nginx-1.10.2/
#./configure --with-http_stub_status_module --prefix=/opt/nginx
# make && make install

启动Nginx

# pwd
/opt/nginx
# ll
总用量 4
drwx------ 2 nobody root    6 4月  22 11:30 client_body_temp
drwxr-xr-x 2 root   root 4096 4月  22 12:53 conf
drwx------ 2 nobody root    6 4月  22 11:30 fastcgi_temp
drwxr-xr-x 2 root   root   40 4月  22 11:29 html
drwxr-xr-x 2 root   root   41 4月  22 14:24 logs
drwx------ 2 nobody root    6 4月  22 11:30 proxy_temp
drwxr-xr-x 2 root   root   19 4月  22 11:29 sbin
drwx------ 2 nobody root    6 4月  22 11:30 scgi_temp
drwx------ 2 nobody root    6 4月  22 11:30 uwsgi_temp
# sbin/nginx

traefik 部署

https://www.cnblogs.com/zisefeizhu/p/12692979.html

环境检查

# kubectl get pods,svc -A | grep traefik
kube-system   pod/traefik-ingress-controller-z5qd7             1/1     Running       0          136m
kube-system   service/traefik                     ClusterIP   10.68.251.132   <none>        80/TCP,443/TCP,8080/TCP        4h14m

浏览器访问

部署应用

这里的测试应用选择containous/whoami镜像

测试应用部署

# cat whoami.yaml 
##########################################################################
#Author:                     zisefeizhu
#QQ:                         2********0
#Date:                       2020-04-22
#FileName:                   whoami.yaml
#URL:                        https://www.cnblogs.com/zisefeizhu/
#Description:                The test script
#Copyright (C):              2020 All rights reserved
###########################################################################
apiVersion: v1
kind: Service
metadata:
  name: whoami
spec:
  ports:
    - protocol: TCP
      name: web
      port: 80
  selector:
    app: whoami
---
kind: Deployment
apiVersion: apps/v1
metadata:
  name: whoami
  labels:
    app: whoami
spec:
  replicas: 2
  selector:
    matchLabels:
      app: whoami
  template:
    metadata:
      labels:
        app: whoami
    spec:
      containers:
        - name: whoami
          image: containous/whoami
          ports:
            - name: web
              containerPort: 80

# kubectl get svc,pod
NAME                 TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)             AGE
service/whoami       ClusterIP   10.68.109.151   <none>        80/TCP              3h30m

NAME                                 READY   STATUS    RESTARTS   AGE
pod/whoami-bd6b677dc-jvqc2           1/1     Running   0          3h30m
pod/whoami-bd6b677dc-lvcxp           1/1     Running   0          3h30m

联调联试

因为选择的解决问题的方案是：nginx --> traefik --> service

traefik -->service
nginx --> traefik
nginx --> service

traefik --> service

使用traefik 代理测试应用的资源清单：

# cat traefik-whoami.yaml 
##########################################################################
#Author:                     zisefeizhu
#QQ:                         2********0
#Date:                       2020-04-22
#FileName:                   traefik-whoami.yaml
#URL:                        https://www.cnblogs.com/zisefeizhu/
#Description:                The test script
#Copyright (C):              2020 All rights reserved
###########################################################################
apiVersion: traefik.containo.us/v1alpha1
kind: IngressRoute
metadata:
  name: simpleingressroute
spec:
  entryPoints:
    - web
  routes:
  - match: Host(`who.linux.com`) && PathPrefix(`/notls`)
    kind: Rule
    services:
    - name: whoami
      port: 80

本地hosts解析

traefik界面观察是代理成功：

访问who.linux.com/notls

nginx --> traefik

# cat conf/nginx.conf
user nobody;
worker_processes 4;
events {
	use epoll;
	worker_connections 2048;
}
http {
	upstream app {
		server  20.0.0.202;  
	}

	server {
		listen 80;
#		server_name who2.linux.com;
  	access_log logs/access.log;
  	error_log logs/error.log;
  	location / {
   		proxy_set_header X-Forwarded-For $remote_addr;
    	proxy_set_header X-Real-IP $remote_addr;
    	proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    	proxy_set_header Host $host;
			proxy_headers_hash_max_size 51200;
			proxy_headers_hash_bucket_size 6400;
    	proxy_redirect off;
    	proxy_read_timeout 600;
    	proxy_connect_timeout 600;
    	proxy_pass http://app;
  	}
	}
}

# cat /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
20.0.0.202  who.linux.com   //k8s集群traefik所落节点，其实K8s任意节点都随便拉
# curl -iL who.linux.com/notls
HTTP/1.1 200 OK
Content-Length: 388
Content-Type: text/plain; charset=utf-8
Date: Wed, 22 Apr 2020 07:33:52 GMT

Hostname: whoami-bd6b677dc-lvcxp
IP: 127.0.0.1
IP: 172.20.46.67
RemoteAddr: 172.20.177.153:58168
GET /notls HTTP/1.1
Host: who.linux.com
User-Agent: curl/7.29.0
Accept: */*
Accept-Encoding: gzip
X-Forwarded-For: 20.0.0.101
X-Forwarded-Host: who.linux.com
X-Forwarded-Port: 80
X-Forwarded-Proto: http
X-Forwarded-Server: traefik-ingress-controller-z5qd7
X-Real-Ip: 20.0.0.101

nginx要是不熟悉就看这大佬的博文吧：https://www.cnblogs.com/kevingrace/p/6095027.html

nginx --> service

# cat /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
20.0.0.101  who.linux.com
# curl -iL who.linux.com/notls
HTTP/1.1 200 OK       //响应信息
Server: nginx/1.10.2    //响应服务    
Date: Wed, 22 Apr 2020 07:27:46 GMT
Content-Type: text/plain; charset=utf-8
Content-Length: 389
Connection: keep-alive

Hostname: whoami-bd6b677dc-jvqc2
IP: 127.0.0.1
IP: 172.20.46.111
RemoteAddr: 172.20.177.153:38298
GET /notls HTTP/1.1
Host: who.linux.com
User-Agent: curl/7.29.0
Accept: */*
Accept-Encoding: gzip
X-Forwarded-For: 20.0.0.101   
X-Forwarded-Host: who.linux.com
X-Forwarded-Port: 80
X-Forwarded-Proto: http
X-Forwarded-Server: traefik-ingress-controller-z5qd7
X-Real-Ip: 20.0.0.101

nginx日志
# tail -f access.log
20.0.0.101 - - [22/Apr/2020:15:28:28 +0800] "GET /notls HTTP/1.1" 200 389 "-" "curl/7.29.0"

浏览器测试

继续测试

把traefik应用给关了，然后再测试

# kubectl delete -f .
configmap "traefik-config" deleted
customresourcedefinition.apiextensions.k8s.io "ingressroutes.traefik.containo.us" deleted
customresourcedefinition.apiextensions.k8s.io "ingressroutetcps.traefik.containo.us" deleted
customresourcedefinition.apiextensions.k8s.io "middlewares.traefik.containo.us" deleted
customresourcedefinition.apiextensions.k8s.io "tlsoptions.traefik.containo.us" deleted
customresourcedefinition.apiextensions.k8s.io "traefikservices.traefik.containo.us" deleted
ingressroute.traefik.containo.us "traefik-dashboard-route" deleted
service "traefik" deleted
daemonset.apps "traefik-ingress-controller" deleted
serviceaccount "traefik-ingress-controller" deleted
clusterrole.rbac.authorization.k8s.io "traefik-ingress-controller" deleted
clusterrolebinding.rbac.authorization.k8s.io "traefik-ingress-controller" deleted

# kubectl delete -f traefik-whoami.yaml   //关闭whoami traefik代理
ingressroute.traefik.containo.us "simpleingressroute" deleted

没得说了测试结果很明确了：访问who.linux.com 流量走向：nginx-->traefik --> service 。

秒客网

解决项目迁移至Kubernetes集群中的代理问题