如何通过iptables将http请求从A服务器转发到B服务器
作者:绿豆淀粉好勾芡儿
这篇文章主要介绍了如何通过iptables将http请求从A服务器转发到B服务器,本文给大家介绍的非常详细,对大家的学习或工作具有一定的参考借鉴价值,需要的朋友可以参考下
1、准备服务器、终端
使用docker的容器来模拟所需的服务器、终端。dockerfile如下:
FROM centos:centos7 as iptables-test RUN yum install -y iptables-services && yum install -y tcpdump
docker-compose.yml如下:
version: "2.7" services: work0: build: . hostname: work0 container_name: work0 privileged: true tty: true networks: default: ipv4_address: 172.24.25.15 work1: build: . hostname: work1 container_name: work1 privileged: true tty: true networks: default: ipv4_address: 172.24.25.16 work2: build: . hostname: work2 container_name: work2 privileged: true tty: true networks: default: ipv4_address: 172.24.25.17 networks: default: external: name: network-public
网络的设置参考如下(也可以按照自己已有的网络设置):
docker network create --driver bridge --subnet 172.24.25.0/24 --gateway 172.24.25.1 network-public
针对docker-compose.yml中三个容器的解释:
- work0充当终端
- work1充当服务器A
- work2充当服务器B
2、准备一个http服务
package main import ( "fmt" "net/http" "os" "os/signal" "time" ) func main() { mux := http.NewServeMux() mux.HandleFunc("/hello", HelloWorld) server := &http.Server{ Addr: ":22345", WriteTimeout: time.Second * 10, Handler: mux, } err := server.ListenAndServe() if err != nil { if err == http.ErrServerClosed { fmt.Println("Server closed under request") } else { fmt.Println("Server closed unexpected", err) } } // 平滑退出 quit := make(chan os.Signal, 1) signal.Notify(quit, os.Interrupt) go func() { <-quit // 接收到退出信号 if err = server.Close(); err != nil { fmt.Println("close service:", err) } }() } func HelloWorld(w http.ResponseWriter, r *http.Request) { t := time.Now().Format("2006-01-02 15:04:05") s := fmt.Sprintf("当前时间: %s\n", t) w.Write([]byte(s)) }
编译后上传到服务器B,即work2容器的 /tmp
目录。假设编译后的包名为: http-service
。
3、设置服务器的iptables
3.1、 首先,确保A服务器上启用了IP转发功能。可以通过运行以下命令来检查:
sysctl net.ipv4.ip_forward
如果返回值为1,则表示IP转发已启用。如果返回值为0,则需要将其启用。可以通过编辑 /etc/sysctl.conf
文件并将 net.ipv4.ip_forward
设置为1来永久启用IP转发。
3.2、 在A服务器上设置iptables规则来将HTTP请求转发到B服务器。可以使用以下命令:
iptables -t nat -A PREROUTING -p tcp --dport 80 -j DNAT --to-destination <B服务器的IP地址>:80 iptables -t nat -A POSTROUTING -p tcp -d <B服务器的IP地址> --dport 80 -j SNAT --to-source <A服务器的IP地址>
这些规则将在 nat
表中添加两条规则。第一条规则将目标端口为80的TCP流量重定向到B服务器的IP地址和端口80。第二条规则将响应流量的源IP地址更改为A服务器的IP地址。
3.3、 确保A服务器上的防火墙允许通过转发的流量。可以使用以下命令来允许转发的流量:
iptables -A FORWARD -p tcp -d <B服务器的IP地址> --dport 80 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT iptables -A FORWARD -p tcp -s <B服务器的IP地址> --sport 80 -m state --state ESTABLISHED,RELATED -j ACCEPT
3.4、 根据前三小节描述,以及docker-compose.yml中的ip分配,和http服务中的端口号,需要执行的命令:
iptables -t nat -A PREROUTING -p tcp --dport 22345 -j DNAT --to-destination 172.24.25.17:22345 iptables -t nat -A POSTROUTING -p tcp -d 172.24.25.17 --dport 22345 -j SNAT --to-source 172.24.25.16 iptables -A FORWARD -p tcp -d 172.24.25.17 --dport 22345 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT iptables -A FORWARD -p tcp -s 172.24.25.17 --sport 22345 -m state --state ESTABLISHED,RELATED -j ACCEPT
4、验证效果
4.1、 在服务器B(work2容器)运行http服务。
cd /tmp && ./http-service
4.2、在终端(work0)请求服务器A
curl 172.24.25.16:22345/hello
4.3、 在终端(work0)查看相应数据
[root@work0 tmp]# curl 172.24.25.16:22345/hello 当前时间: 2023-08-17 06:43:03
4.4、查看服务器A的tcpdump
[root@work1 tmp]# tcpdump tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes 06:43:03.154012 IP work0.network-public.48936 > work1.22345: Flags [S], seq 2220603025, win 64240, options [mss 1460,sackOK,TS val 3194673893 ecr 0,nop,wscale 7], length 0 06:43:03.154157 IP work1.48936 > work2.network-public.22345: Flags [S], seq 2220603025, win 64240, options [mss 1460,sackOK,TS val 3194673893 ecr 0,nop,wscale 7], length 0 06:43:03.154185 IP work1.48936 > work2.network-public.22345: Flags [S], seq 2220603025, win 64240, options [mss 1460,sackOK,TS val 3194673893 ecr 0,nop,wscale 7], length 0 06:43:03.154305 IP work2.network-public.22345 > work1.48936: Flags [S.], seq 578213404, ack 2220603026, win 65160, options [mss 1460,sackOK,TS val 2378678745 ecr 3194673893,nop,wscale 7], length 0 06:43:03.154326 IP work1.22345 > work0.network-public.48936: Flags [S.], seq 578213404, ack 2220603026, win 65160, options [mss 1460,sackOK,TS val 2378678745 ecr 3194673893,nop,wscale 7], length 0 06:43:03.154339 IP work0.network-public.48936 > work1.22345: Flags [.], ack 1, win 502, options [nop,nop,TS val 3194673894 ecr 2378678745], length 0 06:43:03.154341 IP work1.48936 > work2.network-public.22345: Flags [.], ack 1, win 502, options [nop,nop,TS val 3194673894 ecr 2378678745], length 0 06:43:03.154516 IP work0.network-public.48936 > work1.22345: Flags [P.], seq 1:88, ack 1, win 502, options [nop,nop,TS val 3194673894 ecr 2378678745], length 87 06:43:03.154521 IP work1.48936 > work2.network-public.22345: Flags [P.], seq 1:88, ack 1, win 502, options [nop,nop,TS val 3194673894 ecr 2378678745], length 87 06:43:03.154529 IP work2.network-public.22345 > work1.48936: Flags [.], ack 88, win 509, options [nop,nop,TS val 2378678745 ecr 3194673894], length 0 06:43:03.154531 IP work1.22345 > work0.network-public.48936: Flags [.], ack 88, win 509, options [nop,nop,TS val 2378678745 ecr 3194673894], length 0 06:43:03.154943 IP work2.network-public.22345 > work1.48936: Flags [P.], seq 1:152, ack 88, win 509, options [nop,nop,TS val 2378678745 ecr 3194673894], length 151 06:43:03.154950 IP work1.22345 > work0.network-public.48936: Flags [P.], seq 1:152, ack 88, win 509, options [nop,nop,TS val 2378678745 ecr 3194673894], length 151 06:43:03.154997 IP work0.network-public.48936 > work1.22345: Flags [.], ack 152, win 501, options [nop,nop,TS val 3194673894 ecr 2378678745], length 0 06:43:03.155002 IP work1.48936 > work2.network-public.22345: Flags [.], ack 152, win 501, options [nop,nop,TS val 3194673894 ecr 2378678745], length 0 06:43:03.155159 IP work0.network-public.48936 > work1.22345: Flags [F.], seq 88, ack 152, win 501, options [nop,nop,TS val 3194673894 ecr 2378678745], length 0 06:43:03.155166 IP work1.48936 > work2.network-public.22345: Flags [F.], seq 88, ack 152, win 501, options [nop,nop,TS val 3194673894 ecr 2378678745], length 0 06:43:03.155247 IP work2.network-public.22345 > work1.48936: Flags [F.], seq 152, ack 89, win 509, options [nop,nop,TS val 2378678745 ecr 3194673894], length 0 06:43:03.155255 IP work1.22345 > work0.network-public.48936: Flags [F.], seq 152, ack 89, win 509, options [nop,nop,TS val 2378678745 ecr 3194673894], length 0 06:43:03.155350 IP work0.network-public.48936 > work1.22345: Flags [.], ack 153, win 501, options [nop,nop,TS val 3194673895 ecr 2378678745], length 0 06:43:03.155354 IP work1.48936 > work2.network-public.22345: Flags [.], ack 153, win 501, options [nop,nop,TS val 3194673895 ecr 2378678745], length 0
5 版本信息
[root@work1 tmp]# iptables --version iptables v1.4.21
[root@work1 tmp]# cat /etc/*release CentOS Linux release 7.9.2009 (Core) NAME="CentOS Linux" VERSION="7 (Core)" ID="centos" ID_LIKE="rhel fedora" VERSION_ID="7" PRETTY_NAME="CentOS Linux 7 (Core)" ANSI_COLOR="0;31" CPE_NAME="cpe:/o:centos:centos:7" HOME_URL="https://www.centos.org/" BUG_REPORT_URL="https://bugs.centos.org/" CENTOS_MANTISBT_PROJECT="CentOS-7" CENTOS_MANTISBT_PROJECT_VERSION="7" REDHAT_SUPPORT_PRODUCT="centos" REDHAT_SUPPORT_PRODUCT_VERSION="7" CentOS Linux release 7.9.2009 (Core) CentOS Linux release 7.9.2009 (Core)
到此这篇关于通过iptables将http请求从A服务器转发到B服务器的文章就介绍到这了,更多相关iptables将http请求从A服务器转发到B服务器内容请搜索脚本之家以前的文章或继续浏览下面的相关文章希望大家以后多多支持脚本之家!