Nginx负载均衡即为当代理服务器将自定义的域名解析到多个指定IP时，通过upstream来保证用户可以通过代理服务器正常访问各个IP。

• 编辑配置文件

#配置内容
upstream qq #名字自定义
{
    ip_hash;
        #目的：同一个用户保持在同一个服务器上
        # #即当域名指向多个IP时，保证每个用户始终解析到同一IP
    server 61.135.157.156:80;
    server 125.39.240.113:80;
        #指定web服务器的IP
}
server
{
    listen 80;
    server_name www.qq.com;
    location /
    {
        proxy_pass http://qq;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    }
}

截图如下：

• 安装dig

#yum安装
[root@taoyuan ~]# yum install -y bind-utils
#dig 域名解析命令，可以返回多个ip

• 测试

#curl测试
[root@taoyuan ~]# curl -x127.0.0.1:80 www.qq.com
Hello default .
#返回默认虚拟主机


#检验 && 加载
[root@taoyuan ~]# /usr/local/nginx/sbin/nginx -t
nginx: the configuration file /usr/local/nginx/conf/nginx.conf syntax is ok
nginx: configuration file /usr/local/nginx/conf/nginx.conf test is successful
[root@taoyuan ~]# /usr/local/nginx/sbin/nginx -s reload


[root@taoyuan ~]# curl -x127.0.0.1:80 www.qq.com
#结果截图如下

注意： Nginx不支持代理https，只能代理http，新版本的Nginx可以代理tcp。

http、https、tcp

HTTP超文本传输协议（HyperText Transfer Protocol)是互联网上应用最为广泛的一种网络协议。
HTTPS(全称:Hyper Text Transfer Protocol over Secure Socket Layer)，是以安全为目标的HTTP通道，简单讲是HTTP的安全版。HTTPS协议是由SSL+HTTP协议构建的可进行加密传输、身份认证的网络协议要比http协议安全。
HTTP默认的端口号为80，HTTPS的端口号为443。
TCP(Transmission Control Protocol 传输控制协议)是一种面向连接的、可靠的、基于字节流的传输层通信协议，由IETF的RFC 793定义。默认监听80端口。

12.18 ssl原理

SSL(Secure Sockets Layer 安全套接层)协议,及其继任者TLS（Transport Layer Security传输层安全）协议，是为网络通信提供安全及数据完整性的一种安全协议。

• 工作流程

• 浏览器发送一个https的请求给服务器；
• 服务器要有一套数字证书，可以自己制作（后面的操作就是阿铭自己制作的证书），也可以向组织申请，区别就是自己颁发的证书需要客户端验证通过，才可以继续访问，而使用受信任的公司申请的证书则不会弹出>提示页面，这套证书其实就是一对公钥和私钥；
• 服务器会把公钥传输给客户端；
• 客户端（浏览器）收到公钥后，会验证其是否合法有效，无效会有警告提醒，有效则会生成一串随机数，并用收到的公钥加密；
• 客户端把加密后的随机字符串传输给服务器；
• 服务器收到加密随机字符串后，先用私钥解密（公钥加密，私钥解密），获取到这一串随机数后，再用这串随机字符串加密传输的数据（该加密为对称加密，所谓对称加密，就是将数据和私钥也就是这个随机字符串>通过某种算法混合在一起，这样除非知道私钥，否则无法获取数据内容）；
• 服务器把加密后的数据传输给客户端；
• 客户端收到数据后，再用自己的私钥也就是那个随机字符串解密；

12.19 生产ssl密钥对

• 进入conf目录

[root@taoyuan ~]# cd /usr/local/nginx/conf/

• 工具

1. 需要openssl工具来生成；
2. 可以用 rpm -qf which openssl 来查询该命令哪个包的

#如果过没有可以安装一下
[root@taoyuan conf]# rpm -qf `which openssl`
openssl-1.0.2k-8.el7.x86_64


#安装
[root@taoyuan conf]# yum install -y openssl-1.0.2k-8.el7.x86_64

• key文件为私钥

#生成命令
[root@taoyuan conf]# openssl genrsa -des3 -out tmp.key 2048
Generating RSA private key, 2048 bit long modulus
.................................................+++
........+++
e is 65537 (0x10001)
Enter pass phrase for tmp.key:
Verifying - Enter pass phrase for tmp.key:
Verify failure
User interface error
140423990957984:error:0906906F:PEM routines:PEM_ASN1_write_bio:read key:pem_lib.c:385:
#2048 为长度，需要输入密码

• 转换key,取消密码

[root@taoyuan conf]# openssl rsa -in tmp.key -out taoyuan.key
Enter pass phrase for tmp.key:
writing RSA key
#密码比较麻烦，所以取消掉密码
#生成证书请求文件，需要拿这个文件和私钥一起生产公钥文件

• rm -f tmp.key

[root@taoyuan conf]# rm -f tmp.key

• 生成证书请求文件

#命令
[root@taoyuan conf]# openssl req -new -key taoyuan.key -out taoyuan.csr
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter ‘.‘, the field will be left blank.
Country Name (2 letter code) [XX]:
State or Province Name (full name) []:
Locality Name (eg, city) [Default City]:
Organization Name (eg, company) [Default Company Ltd]:
Organizational Unit Name (eg, section) []:
Common Name (eg, your name or your server‘s hostname) []:
Email Address []:


Please enter the following ‘extra‘ attributes
to be sent with your certificate request
A challenge password []:
An optional company name []:
#输入一些信息，可以直接回车

• 生成公钥

[root@taoyuan conf]# openssl x509 -req -days 365 -in taoyuan.csr -signkey taoyuan.key -out taoyuan.crt 
Signature ok
subject=/C=XX/L=Default City/O=Default Company Ltd
Getting Private key


[root@taoyuan conf]# ls taoyuan.
taoyuan.crt  taoyuan.csr  taoyuan.key  
#这里的aminglinux.crt为公钥

12.20 Nginx配置ssl

• 配置ssl.conf //加入如下内容

server
server
{
    listen 443;
    server_name taoyuan.com;
    index index.html index.php;
    root /data/wwwroot/taoyuan.com;
    ssl on;
    ssl_certificate taoyuan.crt;
    ssl_certificate_key taoyuan.key;
    ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
}

• -t && -s reload

#报错unknown directive "ssl"
[root@taoyuan conf]# /usr/local/nginx/sbin/nginx -t
nginx: [emerg] unknown directive "ssl" in /usr/local/nginx/conf/vhost/ssl.conf:7
nginx: configuration file /usr/local/nginx/conf/nginx.conf test failed


#需要重新编译nginx, 加上--with-http_ssl_module


#源码包查看
[root@taoyuan conf]# cd /usr/local/src/nginx-1.8.0/
[root@taoyuan nginx-1.8.0]# ./configure --help |grep -i ssl
  --with-http_ssl_module             enable ngx_http_ssl_module
  --with-mail_ssl_module             enable ngx_mail_ssl_module
  --with-openssl=DIR                 set path to OpenSSL library sources
  --with-openssl-opt=OPTIONS         set additional build options for OpenSSL


#重新编译nginx
[root@taoyuan nginx-1.8.0]# ./configure --prefix=/usr/local/nginx --with-http_ssl_module


#make && make install
#-t restart[重启]
[root@taoyuan nginx-1.8.0]# /usr/local/nginx/sbin/nginx -t
nginx: the configuration file /usr/local/nginx/conf/nginx.conf syntax is ok
nginx: configuration file /usr/local/nginx/conf/nginx.conf test is successful


[root@taoyuan nginx-1.8.0]# /usr/local/nginx/sbin/nginx restart
nginx: invalid option: "restart"
[root@taoyuan nginx-1.8.0]# /etc/init.d/nginx restart
Restarting nginx (via systemctl):                          [  确定  ]


 #查看监听端口
[root@taoyuan nginx-1.8.0]# netstat -lntp
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name    
tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      4622/nginx: master  
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      1000/sshd           
tcp        0      0 127.0.0.1:25            0.0.0.0:*               LISTEN      1371/master         
tcp        0      0 0.0.0.0:443             0.0.0.0:*               LISTEN      4622/nginx: master  
tcp6       0      0 :::22                   :::*                    LISTEN      1000/sshd           
tcp6       0      0 ::1:25                  :::*                    LISTEN      1371/master         
tcp6       0      0 :::3306                 :::*                    LISTEN      1329/mysqld         

• 创建测试文件

[root@taoyuan nginx-1.8.0]# mkdir /data/wwwroot/taoyuan.com


#创建测试文件
[root@taoyuan nginx-1.8.0]# echo "ssl test page." > /data/wwwroot/taoyuan.com/index.html

• 测试

[root@taoyuan nginx-1.8.0]# vi /etc/hosts
# 编辑hosts，增加127.0.0.1 taoyuan.com


root@taoyuan nginx-1.8.0]# curl https://taoyuan.com
curl: (60) Peer‘s certificate issuer has been marked as not trusted by the user.
More details here: http://curl.haxx.se/docs/sslcerts.html


curl performs SSL certificate verification by default, using a "bundle"
 of Certificate Authority (CA) public keys (CA certs). If the default
 bundle file isn‘t adequate, you can specify an alternate file
 using the --cacert option.
If this HTTPS server uses a certificate signed by a CA represented in
 the bundle, the certificate verification probably failed due to a
 problem with the certificate (it might be expired, or the name might
 not match the domain name in the URL).
If you‘d like to turn off curl‘s verification of the certificate, use
 the -k (or --insecure) option.
#不能直接curl 需要用vi /etc/hosts
#显示如下结果表示测试成功

扩展
502问题汇总 http://ask.apelearn.com/question/9109

location优先级 http://blog.lishiming.net/?p=100

Nginx负载均衡、ssl原理、生产ssl密钥对、Nginx配置ssl

原文：http://blog.51cto.com/3622288/2058857