Nginx详解（五）

川长思鸟来 2022-02-23 08:55 474阅读 0赞

## 6. Nginx rewrite 配置（一） ##

nginx的rewrite配置是nginx配置中比较核心的部分，rewrite可以实现域名跳转（重定向）、URL重写（伪静态）、动静分离（跳转域名，并接入CDN实现加速）。rewrite依赖pcre库，用到的模块是ngx\_http\_rewrite\_module。

--------------------

### rewrite相关指令 ###

#### if指令 ####

格式： if （条件判断） \{ 具体的rewrite规则 \}

*  条件举例：

条件判断语句有nginx内置变量、逻辑判断符号和目标字符串三部分组成。
    其中，内置变量是nginx固定的非自定义的变量，如$request_method、$request_uri等。
    逻辑判断符号有 =、!=、~、~*、!~、!~*。
    !表示取反，~为匹配符号，它右侧为正则表达式，区分大小写，而~*为不区分大小写匹配。
    目标字符串可以是正则表达式，通常不用加引号，但表达式中有特殊符号时，比如空格、花括号、分号等，需要用单引号引起来。

*  示例1：

if ($request_method = POST)
    { 
        return 405；
    }

当请求的方法为POST时，直接返回405状态码。if中支持用return指令。

*  示例2：

if ($http_user_agent ~ MSIE )
    { 
        return 403；
    }

user\_agent带有MSIE（IE浏览器）字符的请求，直接返回403状态码。

如果想同时限制多个user\_agent，还可以写成这样：

if ($http_user_agent ~ "MSIE|firefox|spider")
    { 
        return 403；
    }

*  示例3：

if (!-f $request_filename)
    { 
        rewrite 语句；
    }

当请求的文件不存在时，将会执行下面的rewrite规则。

*  示例4：

if ($request_uri ~* 'gid=\d{9,12}/')
    { 
        rewrite 语句；
    }

\\d表示数字，\{9,12\}表示数字出现的次数是9到12次，比如gid=123456789是符合条件的，就会执行下面的rewrite规则。

#### break和last指令 ####

两个指令用法相同，但含义不同，需要放到rewrite规则的末尾，用来控制重写后的链接是否继续被nginx配置执行（主要是rewrite、return指令）。

*  示例1：

# vim /usr/local/nginx/conf/vhost/www.1.com.conf
    
    server { 
        listen 80;
        server_name www.1.com;
        index index.html;
        root /data/wwwroot/www.1.com;
    
        rewrite_log on;                 #打开rewrite日志，在error.log中
        rewrite /1.html /2.html;
        rewrite /2.html /3.html;
    }

重载配置：

# echo "111111" > /data/wwwroot/www.1.com/2.html
    
    # echo "222222" > /data/wwwroot/www.1.com/2.html
    
    # echo "333333" > /data/wwwroot/www.1.com/3.html
    
    # /usr/local/nginx/sbin/nginx -t
    
    # /usr/local/nginx/sbin/nginx -s reload

访问测试：

# curl -x127.0.0.1:80 www.1.com/1.html
    333333

说明已经从1.html跳转到3.html，实际访问到的是3.html。

查看日志：

# tail /usr/local/nginx/logs/error.log
    
    2019/03/11 17:51:27 [notice] 28386#0: *1 "/1.html" matches "/1.html", client: 127.0.0.1, server: www.1.com, request: "GET HTTP://www.1.com/1.html HTTP/1.1", host: "www.1.com"
    2019/03/11 17:51:27 [notice] 28386#0: *1 rewritten data: "/2.html", args: "", client: 127.0.0.1, server: www.1.com, request: "GET HTTP://www.1.com/1.html HTTP/1.1", host: "www.1.com"
    2019/03/11 17:51:27 [notice] 28386#0: *1 "/2.html" matches "/2.html", client: 127.0.0.1, server: www.1.com, request: "GET HTTP://www.1.com/1.html HTTP/1.1", host: "www.1.com"
    2019/03/11 17:51:27 [notice] 28386#0: *1 rewritten data: "/3.html", args: "", client: 127.0.0.1, server: www.1.com, request: "GET HTTP://www.1.com/1.html HTTP/1.1", host: "www.1.com"

*  示例2：

# vim /usr/local/nginx/conf/vhost/www.1.com.conf
    
    server { 
        listen 80;
        server_name www.1.com;
        index index.html;
        root /data/wwwroot/www.1.com;
    
        rewrite_log on;
        rewrite /1.html /2.html break;
        rewrite /2.html /3.html;
    }

重载配置：

# /usr/local/nginx/sbin/nginx -t
    
    # /usr/local/nginx/sbin/nginx -s reload

访问测试：

# curl -x127.0.0.1:80 www.1.com/1.html
    222222

说明这一次是从1.html跳转到2.html，没有继续往下面跳转。

查看日志：

# tail /usr/local/nginx/logs/error.log
    
    2019/03/11 18:02:18 [notice] 28507#0: *2 "/1.html" matches "/1.html", client: 127.0.0.1, server: www.1.com, request: "GET HTTP://www.1.com/1.html HTTP/1.1", host: "www.1.com"
    2019/03/11 18:02:18 [notice] 28507#0: *2 rewritten data: "/2.html", args: "", client: 127.0.0.1, server: www.1.com, request: "GET HTTP://www.1.com/1.html HTTP/1.1", host: "www.1.com"

*  示例3：

重载配置：

# /usr/local/nginx/sbin/nginx -t
    
    # /usr/local/nginx/sbin/nginx -s reload

访问测试：

# curl -x127.0.0.1:80 www.1.com/1.html
    222222

查看日志：

# tail /usr/local/nginx/logs/error.log
    
    2019/03/11 18:08:21 [notice] 28533#0: *3 "/1.html" matches "/1.html", client: 127.0.0.1, server: www.1.com, request: "GET HTTP://www.1.com/1.html HTTP/1.1", host: "www.1.com"
    2019/03/11 18:08:21 [notice] 28533#0: *3 rewritten data: "/2.html", args: "", client: 127.0.0.1, server: www.1.com, request: "GET HTTP://www.1.com/1.html HTTP/1.1", host: "www.1.com"

说明这一次也是从1.html跳转到2.html，没有继续往下面跳转。**在server部分配置break和last作用一致**。

*  示例4：

# vim /usr/local/nginx/conf/vhost/www.1.com.conf
    
    server { 
        listen 80;
        server_name www.1.com;
        index index.html;
        root /data/wwwroot/www.1.com;
    
        rewrite_log on;
    
        location / { 
        rewrite /1.html /2.html;
        rewrite /2.html /3.html;
        }
    
        location /2.html { 
        rewrite /2.html /a.html;
        }
    
        location /3.html { 
        rewrite /3.html /b.html;
        }
    }

重载配置：

# /usr/local/nginx/sbin/nginx -t
    
    # /usr/local/nginx/sbin/nginx -s reload

访问测试：

# curl -x127.0.0.1:80 www.1.com/1.html
    
    <html>
    <head><title>404 Not Found</title></head>
    <body bgcolor="white">
    <center><h1>404 Not Found</h1></center>
    <hr><center>nginx</center>
    </body>
    </html>

查看日志：

# tail /usr/local/nginx/logs/error.log
    
    2019/03/11 18:18:11 [notice] 6932#0: signal 17 (SIGCHLD) received from 28533
    2019/03/11 18:18:27 [notice] 28558#0: *4 "/1.html" matches "/1.html", client: 127.0.0.1, server: www.1.com, request: "GET HTTP://www.1.com/1.html HTTP/1.1", host: "www.1.com"
    2019/03/11 18:18:27 [notice] 28558#0: *4 rewritten data: "/2.html", args: "", client: 127.0.0.1, server: www.1.com, request: "GET HTTP://www.1.com/1.html HTTP/1.1", host: "www.1.com"
    2019/03/11 18:18:27 [notice] 28558#0: *4 "/2.html" matches "/2.html", client: 127.0.0.1, server: www.1.com, request: "GET HTTP://www.1.com/1.html HTTP/1.1", host: "www.1.com"
    2019/03/11 18:18:27 [notice] 28558#0: *4 rewritten data: "/3.html", args: "", client: 127.0.0.1, server: www.1.com, request: "GET HTTP://www.1.com/1.html HTTP/1.1", host: "www.1.com"
    2019/03/11 18:18:27 [notice] 28558#0: *4 "/3.html" matches "/3.html", client: 127.0.0.1, server: www.1.com, request: "GET HTTP://www.1.com/1.html HTTP/1.1", host: "www.1.com"
    2019/03/11 18:18:27 [notice] 28558#0: *4 rewritten data: "/b.html", args: "", client: 127.0.0.1, server: www.1.com, request: "GET HTTP://www.1.com/1.html HTTP/1.1", host: "www.1.com"
    2019/03/11 18:18:27 [notice] 28558#0: *4 "/1.html" does not match "/b.html", client: 127.0.0.1, server: www.1.com, request: "GET HTTP://www.1.com/1.html HTTP/1.1", host: "www.1.com"
    2019/03/11 18:18:27 [notice] 28558#0: *4 "/2.html" does not match "/b.html", client: 127.0.0.1, server: www.1.com, request: "GET HTTP://www.1.com/1.html HTTP/1.1", host: "www.1.com"
    2019/03/11 18:18:27 [error] 28558#0: *4 open() "/data/wwwroot/www.1.com/b.html" failed (2: No such file or directory), client: 127.0.0.1, server: www.1.com, request: "GET HTTP://www.1.com/1.html HTTP/1.1", host: "www.1.com"

首先匹配到1.html，1.html跳转到2.html；再匹配到2.html，2.html又跳转到3.html；接下来匹配到3.html，3.html跳转到b.html；b.html还会继续匹配，但没有匹配到，所以访问b.html，因为b.html不存在，所以返回404状态码。

*  示例5：

如果我们在server部分使用了location，那break和last的作用就有区别了。

# vim /usr/local/nginx/conf/vhost/www.1.com.conf
    
    server { 
        listen 80;
        server_name www.1.com;
        index index.html;
        root /data/wwwroot/www.1.com;
    
        rewrite_log on;
    
        location / { 
        rewrite /1.html /2.html break;
        rewrite /2.html /3.html;
        }
    
        location /2.html { 
        rewrite /2.html /a.html;
        }
    
        location /3.html { 
        rewrite /3.html /b.html;
        }
    }

重载配置：

# /usr/local/nginx/sbin/nginx -t
    
    # /usr/local/nginx/sbin/nginx -s reload

访问测试：

# curl -x127.0.0.1:80 www.1.com/1.html
    222222

查看日志：

# tail /usr/local/nginx/logs/error.log
    
    2019/03/11 18:32:55 [notice] 6750#0: *5 "/1.html" matches "/1.html", client: 127.0.0.1, server: www.1.com, request: "GET HTTP://www.1.com/1.html HTTP/1.1", host: "www.1.com"
    2019/03/11 18:32:55 [notice] 6750#0: *5 rewritten data: "/2.html", args: "", client: 127.0.0.1, server: www.1.com, request: "GET HTTP://www.1.com/1.html HTTP/1.1", host: "www.1.com"

可以看到，只rewrite一次，从1.html跳转到2.html就直接退出，后面的location部分也不再执行了。

*  示例6：

如果我们在server部分使用了location，那break和last的作用就有区别了。

# vim /usr/local/nginx/conf/vhost/www.1.com.conf
    
    server { 
        listen 80;
        server_name www.1.com;
        index index.html;
        root /data/wwwroot/www.1.com;
    
        rewrite_log on;
    
        location / { 
        rewrite /1.html /2.html last;
        rewrite /2.html /3.html;
        }
    
        location /2.html { 
        rewrite /2.html /a.html;
        }
    
        location /3.html { 
        rewrite /3.html /b.html;
        }
    }

重载配置：

# /usr/local/nginx/sbin/nginx -t
    
    # /usr/local/nginx/sbin/nginx -s reload

访问测试：

查看日志：

# tail /usr/local/nginx/logs/error.log
    
    2019/03/11 18:38:57 [notice] 6759#0: *6 "/1.html" matches "/1.html", client: 127.0.0.1, server: www.1.com, request: "GET HTTP://www.1.com/1.html HTTP/1.1", host: "www.1.com"
    2019/03/11 18:38:57 [notice] 6759#0: *6 rewritten data: "/2.html", args: "", client: 127.0.0.1, server: www.1.com, request: "GET HTTP://www.1.com/1.html HTTP/1.1", host: "www.1.com"
    2019/03/11 18:38:57 [notice] 6759#0: *6 "/2.html" matches "/2.html", client: 127.0.0.1, server: www.1.com, request: "GET HTTP://www.1.com/1.html HTTP/1.1", host: "www.1.com"
    2019/03/11 18:38:57 [notice] 6759#0: *6 rewritten data: "/a.html", args: "", client: 127.0.0.1, server: www.1.com, request: "GET HTTP://www.1.com/1.html HTTP/1.1", host: "www.1.com"
    2019/03/11 18:38:57 [notice] 6759#0: *6 "/1.html" does not match "/a.html", client: 127.0.0.1, server: www.1.com, request: "GET HTTP://www.1.com/1.html HTTP/1.1", host: "www.1.com"
    2019/03/11 18:38:57 [notice] 6759#0: *6 "/2.html" does not match "/a.html", client: 127.0.0.1, server: www.1.com, request: "GET HTTP://www.1.com/1.html HTTP/1.1", host: "www.1.com"
    2019/03/11 18:38:57 [error] 6759#0: *6 open() "/data/wwwroot/www.1.com/a.html" failed (2: No such file or directory), client: 127.0.0.1, server: www.1.com, request: "GET HTTP://www.1.com/1.html HTTP/1.1", host: "www.1.com"

先从1.html跳转到2.html，因为有last，所以本location段内的下面的内容不再执行，但是会继续执行下面的location段，最后匹配到2.html（因为比 / 更精准），从2.html跳转到a.html，因为a.html不存在，所以返回404状态码。

综上，我们可以得到结论：

* 当rewrite规则在location{}外，break和last作用一样，遇到break或last后，其后续的rewrite/return语句不再执行。但后续有location{}的话，还会近一步执行location{}里面的语句,当然前提是请求必须要匹配该location。
    
    * 当rewrite规则在location{}里，遇到break后，本location{}与其他location{}的所有rewrite/return规则都不再执行。
    
    * 当rewrite规则在location{}里，遇到last后，本location{}里后续rewrite/return规则不执行，但重写后的url再次从头开始执行所有规则，哪个匹配执行哪个。

--------------------

### return用法 ###

return指令一般用于对请求的客户端直接返回响应状态码。在该作用域内return后面的所有nginx配置都是无效的。可以使用在server、location以及if配置中。

除了支持跟状态码，还可以跟字符串和url链接。

#### 返回状态码 ####

*  示例1：

server { 
        listen 80;
        server_name www.1.com;
        return 403;
        rewrite /(.*) /abc/$1;               #该行配置不会被执行
    }

`.*`表示所有，$1表示前面的`.*`

# vim /usr/local/nginx/conf/vhost/default.conf
    
    server { 
        listen 80 default_server;
        return 403;
        rewrite /(.*) /abc/$1;
    }
    
    # /usr/local/nginx/sbin/nginx -s reload
    
    # curl -x127.0.0.1:80 e2rwejqw.com
    
    <html>
    <head><title>403 Forbidden</title></head>               #返回403
    <body bgcolor="white">
    <center><h1>403 Forbidden</h1></center>
    <hr><center>nginx</center>
    </body>
    </html>

*  示例2：

server { 
    ......
        if ( $request_uri ~ "\.htpasswd|\.bak" ) { 
            return 405;
            rewrite /(.*) /aaa.txt;               #该行配置不会被执行 
        }
        
        #如果下面还有其他配置，会被执行
        ......
    }

# vim /usr/local/nginx/conf/vhost/www.1.com.conf
    
    server { 
        listen 80;
        server_name www.1.com;
        index index.html;
        root /data/wwwroot/www.1.com;
    
        rewrite_log on;
    
        if ( $request_uri ~ "\.htpasswd|\.bak" ) { 
            return 405;
            rewrite /(.*) /aaa.txt;                                   
        }
    }
    
    # /usr/local/nginx/sbin/nginx -s reload
    
    # curl -x127.0.0.1:80 www.1.com/123/.htpasswd -I
    
    HTTP/1.1 405 Not Allowed                #返回405
    Server: nginx
    Date: Mon, 11 Mar 2019 08:20:55 GMT
    Content-Type: text/html
    Content-Length: 166
    Connection: keep-alive

#### 返回字符串 ####

*  示例3：

server { 
        listen 80;
        server_name www.1.com;
        return 200 "hello";
    }

**如果想返回字符串，必须加上状态码，否则会报错**。

# vim /usr/local/nginx/conf/vhost/www.1.com.conf
    
    server { 
        listen 80;
        server_name www.1.com;
        index index.html;
        root /data/wwwroot/www.1.com;
    
        rewrite_log on;
    
        if ( $request_uri ~ "\.htpasswd|\.bak" ) { 
            return 200 "error";
            rewrite /(.*) /aaa.txt;                                   
        }
    }
    
    # /usr/local/nginx/sbin/nginx -s reload
    
    # curl -x127.0.0.1:80 www.1.com/123/.htpasswd -I
    
    HTTP/1.1 200 OK
    Server: nginx
    Date: Mon, 11 Mar 2019 08:26:58 GMT
    Content-Type: application/octet-stream
    Content-Length: 5
    Connection: keep-alive
    
    # curl -x127.0.0.1:80 www.1.com/123/.htpasswd
    error

另外还可以支持JSON数据；支持写一个变量；支持html代码。

*  场景实战：

背景：网站被黑，凡是在百度点击到本网站的请求，全部都跳转到一个赌博网站。

通过nginx解决：

server { 
    ......
        if ( $http_referer ~ 'baidu.com' ) { 
            return 200 "<html><script>window.location.href='//$host$request_uri';</script></html>";
        }
    }

如果写成：`return http://$host$reauest_uri;`，这在浏览器中会提示“重定向的次数过多”。

# vim /usr/local/nginx/conf/vhost/www.1.com.conf
    
    server { 
        listen 80;
        server_name www.1.com;
        index index.html;
        root /data/wwwroot/www.1.com;
    
        rewrite_log on;
    
        if ( $request_uri ~ "\.htpasswd|\.bak" ) { 
            return 200 "<html><script>window.location.href='//$host$request_uri';</script></html>";
            rewrite /(.*) /aaa.txt;
        }
    }
    
    # /usr/local/nginx/sbin/nginx -s reload
    
    # curl -x127.0.0.1:80 www.1.com/123/.htpasswd -I
    
    HTTP/1.1 200 OK
    Server: nginx
    Date: Mon, 11 Mar 2019 08:54:17 GMT
    Content-Type: application/octet-stream
    Content-Length: 79
    Connection: keep-alive
    
    # curl -x127.0.0.1:80 www.1.com/123/.htpasswd
    
    <html><script>window.location.href='//www.1.com/123/.htpasswd';</script></html>             #返回的就是域名和链接

#### 返回url ####

*  示例4：

server { 
        listen 80;
        server_name www.1.com;
        return http://www.baidu.com;
        rewrite /(.*) /abc/$1;              #该行配置不会被执行
    }

注意：return后面的url必须是以`http://`或者`https://`开头的。

# vim /usr/local/nginx/conf/vhost/www.1.com.conf
    
    server { 
        listen 80;
        server_name www.1.com;
        index index.html;
        root /data/wwwroot/www.1.com;
    
        rewrite_log on;
    
        if ( $request_uri ~ "\.htpasswd|\.bak" ) { 
            return http://www.baidu.com;
            rewrite /(.*) /abc/$1;
        }
    }
    
    # /usr/local/nginx/sbin/nginx -s reload
    
    # curl -x127.0.0.1:80 www.1.com/123/.htpasswd -I
    
    HTTP/1.1 302 Moved Temporarily
    Server: nginx
    Date: Mon, 11 Mar 2019 08:44:07 GMT
    Content-Type: text/html
    Content-Length: 154
    Connection: keep-alive
    Location: http://www.baidu.com              #临时重定向到www.baidu.com

url前面也可以加状态码，但只能是301或302，如果是200，这url会变成字符串返回。

# vim /usr/local/nginx/conf/vhost/www.1.com.conf
    
    server { 
        listen 80;
        server_name www.1.com;
        index index.html;
        root /data/wwwroot/www.1.com;
    
        rewrite_log on;
    
        if ( $request_uri ~ "\.htpasswd|\.bak" ) { 
            return 200 http://www.baidu.com;
            rewrite /(.*) /abc/$1;
        }
    }
    
    # /usr/local/nginx/sbin/nginx -s reload
    
    # curl -x127.0.0.1:80 www.1.com/123/.htpasswd -I
    
    HTTP/1.1 200 OK
    Server: nginx
    Date: Mon, 11 Mar 2019 09:02:15 GMT
    Content-Type: application/octet-stream
    Content-Length: 20
    Connection: keep-alive
    
    # curl -x127.0.0.1:80 www.1.com/123/.htpasswd
    http://www.baidu.com

--------------------