目录：

1.安装
2.使用
3.遇到的坑

详情：

1.安装nginx：

@ brew search nginx
@ brew install nginx
@ 验证是否成功：nginx -v
@ 启动：sudo nginx
@ 重新启动：sudo nginx -s reload
@ 快速关闭 nginx -s stop
@ 优雅的关闭 nginx -s quit

2.nginx反向代理使用
nginx 及其模块的工作由配置文件定义，默认的配置文件为 nginx.conf，该配置文件可能位于：/usr/local/nginx/conf, /etc/nginx, or /usr/local/etc/nginx
--------nginx.conf代码

user  www www;
worker_processes  2;

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

pid        logs/nginx.pid;

events {
    use epoll;
    worker_connections  2048;
}

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

    #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  65;

  # gzip压缩功能设置

  # http_proxy 设置

  # 设定负载均衡后台服务器列表 
    upstream  backend  { 
              #ip_hash; 
              server   192.168.10.100:8080 max_fails=2 fail_timeout=30s ;  
              server   192.168.10.101:8080 max_fails=2 fail_timeout=30s ;  
    }

  # 很重要的虚拟主机配置
    server {
        listen       80;
        server_name  itoatest.example.com;
        root   /apps/oaapp;
      charset utf-8;
        access_log  logs/host.access.log  main;

        #对 / 所有做负载均衡+反向代理
        location / {
            root   /apps/oaapp;
            index  index.jsp index.html index.htm;

            proxy_pass        http://backend;  
            proxy_redirect off;
            # 后端的Web服务器可以通过X-Forwarded-For获取用户真实IP
            proxy_set_header  Host  $host;
            proxy_set_header  X-Real-IP  $remote_addr;  
            proxy_set_header  X-Forwarded-For  $proxy_add_x_forwarded_for;
            proxy_next_upstream error timeout invalid_header http_500 http_502 http_503 http_504;
            
        }

        #静态文件，nginx自己处理，不去backend请求tomcat
        location  ~* /download/ {  
            root /apps/oa/fs;  
            
        }
        location ~ .*\.(gif|jpg|jpeg|bmp|png|ico|txt|js|css)$   
        {   
            root /apps/oaapp;   
            expires      7d; 
        }
        location /nginx_status {
            stub_status on;
            access_log off;
            allow 192.168.10.0/24;
            deny all;
        }

        location ~ ^/(WEB-INF)/ {   
            deny all;   
        }
        #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;
        }
    }
# 在servers文件中创建新service文件并include进来
    include servers/*;

  ## 其它虚拟主机，server 指令开始
}

在nginx.conf中反向代理最重要的指令是 proxy_pass；并且通过 location 匹配 url 路径，将其转发到另外一个服务器处理。
-------Nginx入门之静态资源与动态访问分离
参考：https://blog.csdn.net/jiachengwin/article/details/75106861

3.遇到的问题

• nginx: [emerg] bind() to 0.0.0.0:8080 failed (48: Address already in use)
  解决：我设定的8080端口被占用，我这边是关掉tomcat
• nginx映射PHP文件，导致PHP文件下载而非打开网页
  解决：下载PHP-fpm, 设置fastcgi配置

    location ~ \.php$ {
            root  XXX;
            fastcgi_pass  127.0.0.1:9000;
            fastcgi_index index.php;
            fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
            include fastcgi_params;
        }

参考：https://blog.csdn.net/dengjiexian123/article/details/53358452
解释：
-- 1、location ~ .php?.*${ }代表一个能匹配对应uri的location

-- 2、FastCGI 是一个协议，它是应用程序和 WEB 服务器连接的桥梁。Nginx 并不能直接与 PHP-FPM 通信，而是将请求通过 FastCGI 交给 PHP-FPM 处理, fastcgi_pass 就是把所有 php 请求转发给 php-fpm 进行处理。通过 netstat -nplt 命令可以看到，127.0.0.1:9000 这个端口上运行的进程就是 php-fpm.
-- 3、fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;

Here's what the documentation says:
a. $request_filename
This variable is equal to path to the file for the current request, formed from directives root or alias and URI request;
b. $document_root
This variable is equal to the value of directive root for the current request
c. $fastcgi_script_nameThis variable is equal to the URI request or, if if the URI concludes with a forward slash, then the URI request plus the name of the index file given by fastcgi_index. It is possible to use this variable in place of both SCRIPT_FILENAME and PATH_TRANSLATED, utilized, in particular, for determining the name of the script in PHP.

-- 4、include fastcgi_params; 引入fastcgi配置文件

• 安装php.npm遇到的问题
  --- 1.

$ php-fpm
[11-Jan-2014 16:03:03] ERROR: failed to open configuration file '/private/etc/php-fpm.conf': No such file or directory (2)
[11-Jan-2014 16:03:03] ERROR: failed to load configuration file '/private/etc/php-fpm.conf'
[11-Jan-2014 16:03:03] ERROR: FPM initialization failed

解决：cp /private/etc/php-fpm.conf.default /usr/local/etc/php-fpm.conf
--- 2.

$ php-fpm --fpm-config /usr/local/etc/php-fpm.conf
[11-Jan-2014 16:10:49] ERROR: failed to open error_log (/usr/var/log/php-fpm.log): No such file or directory (2)
[11-Jan-2014 16:10:49] ERROR: failed to post process the configuration
[11-Jan-2014 16:10:49] ERROR: FPM initialization failed

解决：原因是默认在/usr/var目录下工作，可以修改配置文件指定正确的日志文件路径；因此打开$ vim /usr/local/etc/php-fpm.conf，去掉error-log前面的;,并且修改为error_log = /usr/local/var/log/php-fpm.log，再运行sudo php-fpm即可