nginx实现动静分离

对于静态资源比如图片，js，css等文件，我们可以在反向代理服务器nginx中进行缓存。这样浏览器在请求一个静态资源时，代理服务器nginx就可以直接处理，而不用将请求转发给后端服务器tomcat。用户请求的动态文件比如servlet,jsp则转发给Tomcat服务器处理，从而实现动静分离。这也是反向代理服务器的一个重要的作用。
服务器
服务器名称系统版本预装软件 IP地址
Nginx服务器 CentOS 7 Nginx 192.168.110.134
Tomcat服务器A CentOS 7 tomcat+jdk 192.168.110.129
Tomcat服务器B CentOS 7 tomcat+jdk 192.168.110.130
Tomcat服务器C CentOS 7 tomcat+jdk 192.168.110.131

新建一个jsp文件显示服务端的ip地址与图片

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>server index</title>
</head>
<body>
hello！
<%="server ip:"+request.getLocalAddr()%>
<p>
<img src="img/89.jpg" width="600px" height="400px" alt="烤肉">
</p>
</body>
</html>

image.png

将项目打成war包部署到 Tomcat服务器A ，B, C中

再配置 nginx 服务器实现负载均衡
负载均衡实现可见 https://www.jianshu.com/p/75c7b9b4007c
此外在nginx上加上如下语句对静态资源进行拦截

            #静态交给nginx处理   注：d为day， h为hour
            location ~ .*\.(htm|html|gif|jpg|jpeg|png|bmp|swf|ioc|rar|zip|txt|flv|mid|doc|ppt|pdf|xls|mp3|wma)$
            {
                    root  /usr/local/webapps;
                    expires 30d;
            }
            location ~ .*\.(js|css)?$
            {
                    root /usr/local/webapps;
                    expires 1h;
            }

nginx.conf配置

#user  nobody;
worker_processes  1;

#error_log  logs/error.log;
#error_log  logs/error.log  notice;
#error_log  logs/error.log  info;

#pid        logs/nginx.pid;


events {
    worker_connections  1024;
}


http {
    include       mime.types;
    default_type  application/octet-stream;

#设定负载均衡的服务器列表
 upstream testnginx.com {
   #weigth参数表示权值，权值越高被分配到的几率越大
   server 192.168.110.129:8080 weight=1 max_fails=1 fail_timeout=30s;
   server 192.168.110.130:8080 weight=1 max_fails=2 fail_timeout=30s;
   server 192.168.110.131:8080 weight=1 max_fails=3 fail_timeout=30s;
  }

    #log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
    #                  '$status $body_bytes_sent "$http_referer" '
    #                  '"$http_user_agent" "$http_x_forwarded_for"';

    #access_log  logs/access.log  main;

    sendfile        on;
    #tcp_nopush     on;

    #keepalive_timeout  0;
    keepalive_timeout  65;

    #gzip  on;

    server {
        listen       8888;
       server_name  localhost;
       #server_name 192.168.12.137;
        #charset koi8-r;

        #access_log  logs/host.access.log  main;

        location / {
             proxy_pass http://testnginx.com;
             proxy_redirect default;
            root   html;
            index  index.html index.htm hello.jsp;
        }
                #
            location ~ .*\.(htm|html|gif|jpg|jpeg|png|bmp|swf|ioc|rar|zip|txt|flv|mid|doc|ppt|pdf|xls|mp3|wma)$
            {
                    root  /usr/local/webapps;
                    expires 30d;
            }

            location ~ .*\.(js|css)?$
            {
                    root /usr/local/webapps;
                    expires 1h;
            }


        #error_page  404              /404.html;

        # redirect server error pages to the static page /50x.html
        #
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }

        # proxy the PHP scripts to Apache listening on 127.0.0.1:80
        #
        #location ~ \.php$ {
        #    proxy_pass   http://127.0.0.1;
        #}
       # pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
        #
        #location ~ \.php$ {
        #    root           html;
        #    fastcgi_pass   127.0.0.1:9000;
        #    fastcgi_index  index.php;
        #    fastcgi_param  SCRIPT_FILENAME  /scripts$fastcgi_script_name;
        #    include        fastcgi_params;
        #}

        # deny access to .htaccess files, if Apache's document root
        # concurs with nginx's one
        #
        #location ~ /\.ht {
        #    deny  all;
        #}

    }

   # another virtual host using mix of IP-, name-, and port-based configuration
    #
    #server {
    #    listen       8000;
    #    listen       somename:8080;
    #    server_name  somename  alias  another.alias;

    #    location / {
    #        root   html;
    #        index  index.html index.htm;
    #    }
    #}


    # HTTPS server
    #
    #server {
    #    listen       443 ssl;
    #    server_name  localhost;

    #    ssl_certificate      cert.pem;
    #    ssl_certificate_key  cert.key;

    #    ssl_session_cache    shared:SSL:1m;
    #    ssl_session_timeout  5m;

    #    ssl_ciphers  HIGH:!aNULL:!MD5;
    #    ssl_prefer_server_ciphers  on;

    #    location / {
    #        root   html;
    #        index  index.html index.htm;
    #    }
    #}

}

此时访问会出现图片加载不出来的情况

image.png

原因为对静态资源进行了拦截，可以将静态资源如 html js css img 等部署到nginx中来访问
在nginx 目录 /usr/local/webapps 下新建访问的项目名及将对应的静态目录文件拷贝到项目名下

image.png

重新再访问，可以再次访问静态图片了，至此利用nginx实现了动静分离。

image.png