基于Nginx实现一个自己的HTTP模块

/usr/local/nginx/conf/nginx.conf文件例如以下：

#worker工作进程的用户及用户组
user  weijl;
#Nginx worker进程个数
worker_processes  1;

#error日志的设置，默认logs/error.log error
#error_log  logs/error.log;
#error_log  logs/error.log  notice;
#error_log  logs/error.log  info;

#pid文件的路径
#pid        logs/nginx.pid;

events {
    worker_connections  1024;
}

http {
    #嵌入配置文件mime.types
    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  0;
    keepalive_timeout  65;

    #gzip  on;

    upstream test.proxy.com {
        #ip_hash;
        server 192.168.0.7;
        server 192.168.0.8;
    }

    server {
        listen       127.0.0.1:80;
        server_name  test.proxy.com;

        #charset koi8-r;

        #access_log  logs/host.access.log  main;

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

        #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;
        }

	#静态图片资源
	location /image/ {
            root /home/weijl/workspace/;
            autoindex on;
        }

	 #反向代理
        location /proxy_loc/ {
	    root html;
            proxy_set_header Host $host;
            proxy_pass http://test.proxy.com;
            #禁用缓存
            proxy_buffering off;
	    proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
	    client_max_body_size 100m;
        }

	#实现自己的HTTP模块
	location /test {
	    mytest;
	    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;
    #    }
    #}

}

匹配uri,在/usr/local/nginx/html/文件夹下创建文件夹test:

weijl@weijl-ubuntu:/usr/local/nginx/html$ sudo mkdir test

weijl@weijl-ubuntu:/usr/local/nginx/html$ sudo chmod -R 777 test/

实现自己的HTTP模块C代码/home/weijl/workspace/nginx-1.10.3/src/http/ngx_http_mytest_module.c例如以下：

#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_http.h>

//请求包体接收完后回调的函数
void ngx_http_mytest_body_handler(ngx_http_request_t *r)
{

}

//HTTP的HTTP_CONTENT_PHASE阶段mytest模块介入处理http请求内容
static ngx_int_t ngx_http_mytest_handler(ngx_http_request_t *r)
{
		//必须时GET或者HEAD方法，否则返回405 Not Allowed
		if(!(r->method &(NGX_HTTP_GET | NGX_HTTP_HEAD)))
		{
			    ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "weijl NGX_HTTP_NOT_ALLOWED");
				return NGX_HTTP_NOT_ALLOWED;
		}

		//丢弃请求中的包体
		ngx_int_t rc = ngx_http_discard_request_body(r);
		if(rc != NGX_OK)
		{
			 	ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "weijl rc=%d", rc);
				return rc;
		}

		/*设置返回的Content_Type。

注意，ngx_str_t有一个非常方便的初始化宏ngx_string,它能够把ngx_str_t的data和len成员都设置好*/
		ngx_str_t type = ngx_string("text/plain");
		//返回的包体内容
		ngx_str_t response = ngx_string("Hello world! Here is the first Nginx HTTP program!");
		ngx_str_t ress = ngx_string("<html>\r\n<head>\r\n<title>Welcome to nginx!</title>\r\n</head>\r\n<body bgcolor=\"white\" text=\"black\">\r\n<center><h1>Welcome to 192.168.0.7</h1></center>\r\n</body>\r\n</html>\r\n");
		//设置返回状态码
		r->headers_out.status = NGX_HTTP_OK;
		//响应包是由包体内容的，须要设置Conten-Length长度
		r->headers_out.content_length_n = response.len + ress.len;
		//设置Content-Type
		r->headers_out.content_type = type;

		//发送HTTP头部
		rc = ngx_http_send_header(r);
		if(rc == NGX_ERROR || rc > NGX_OK || r->header_only)
		{
				ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "weijl rc=%d", rc);
				return rc;
		}

		//构造ngx_buf_t结构体准备发送包体
		ngx_buf_t *b, *bs;
		b = ngx_create_temp_buf(r->pool, response.len);
		if(NULL == b)
		{
			    ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "weijl b=NULL");
				return NGX_HTTP_INTERNAL_SERVER_ERROR;
		}

		//将Hello World拷贝到ngx_buf_t指向的内存中
		ngx_memcpy(b->pos, response.data, response.len);
		//注意，一定要设置好last指针
		b->last = b->pos + response.len;
		//声明这是最后一块缓冲区
		b->last_buf = 0;

		bs = ngx_create_temp_buf(r->pool, ress.len);
		if(NULL == bs)
		{
				ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "weijl bs=NULL");
				return NGX_HTTP_INTERNAL_SERVER_ERROR;
		}
		//将ress拷贝到ngx_buf_t指向的内存中
		ngx_memcpy(bs->pos, ress.data, ress.len);
		//注意，一定要设置好last指针
		bs->last = bs->pos + ress.len;
		//声明这是最后一块缓冲区
		bs->last_buf = 1;

		//构造发送时的ngx_chain_t结构体
		ngx_chain_t out, outs;
		out.buf = b;
		//设置next为NULL
		out.next = &outs;

		outs.buf = bs;
		outs.next = NULL;

		ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "weijl 最后一步为发送包体。发送结束后HTTP框架会调用ngx_http_finalize_request方法结束请求\n");

		//最后一步为发送包体。发送结束后HTTP框架会调用ngx_http_finalize_request方法结束请求
		return ngx_http_output_filter(r, &out);
}

//没有什么工作必须在HTTP框架初始化时完毕，不必实现ngx_http_module_t的8个回调方法
static ngx_http_module_t ngx_http_mytest_module_ctx =
{
		NULL,
		NULL,

		NULL,
		NULL,

		NULL,
		NULL,

		NULL,
		NULL
};

//“mytest”配置项解析的回调方法
static char *ngx_http_mytest(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
		ngx_http_core_loc_conf_t  *clcf;
		clcf = ngx_http_conf_get_module_loc_conf(cf, ngx_http_core_module);

		clcf->handler = ngx_http_mytest_handler;

		return NGX_CONF_OK;
}

//mytest配置项的处理
static ngx_command_t  ngx_http_mytest_commands[] = {
		{ngx_string("mytest"),
		NGX_HTTP_MAIN_CONF | NGX_HTTP_SRV_CONF | NGX_HTTP_LOC_CONF | NGX_HTTP_LMT_CONF | NGX_CONF_NOARGS,
		ngx_http_mytest,//在出现配置项mytest时调用ngx_http_mytest解析
		NGX_HTTP_LOC_CONF_OFFSET,
		0,
		NULL},

		//很多其它的配置项能够在这里定义

		ngx_null_command
};

//定义mytest模块
ngx_module_t  ngx_http_mytest_module = {
    NGX_MODULE_V1,
    &ngx_http_mytest_module_ctx,             /* module context */
    ngx_http_mytest_commands,                /* module directives */
    NGX_HTTP_MODULE,                       /* module type */
    NULL,                                  /* init master */
    NULL,                                  /* init module */
    NULL,                                  /* init process */
    NULL,                                  /* init thread */
    NULL,                                  /* exit thread */
    NULL,                                  /* exit process */
    NULL,                                  /* exit master */
    NGX_MODULE_V1_PADDING
};

将自己的HTTP模块代码编译进Nginx

在文件夹/home/weijl/workspace/nginx-1.10.3/src/http/下创建文件config:

weijl@weijl-ubuntu:~/workspace/nginx-1.10.3/src/http$ sudo touch config

config文件内容例如以下：

ngx_addon_name=ngx_http_mytest_module

HTTP_MODULES="$HTTP_MODULES ngx_http_mytest_module"

NGX_ADDON_SRCS="$NGX_ADDON_SRCS $ngx_addon_dir/ngx_http_mytest_module.c"

開始nginx的编译与又一次安装

进入Nginx源码文件夹/home/weijl/workspace/nginx-1.10.3下，依次运行例如以下命令：

weijl@weijl-ubuntu:~/workspace/nginx-1.10.3$ sudo ./configure --prefix=/usr/local/nginx --with-http_realip_module --with-http_sub_module --with-http_flv_module
--with-http_dav_module --with-http_gzip_static_module --with-http_stub_status_module --with-http_addition_module --with-pcre=/home/weijl/download/pcre-8.39 --with-openssl=/home/weijl/download/openssl-1.1.0e --with-http_ssl_module --with-zlib=/home/weijl/download/zlib-1.2.11
--add-module=/home/weijl/workspace/nginx-1.10.3/src/http

weijl@weijl-ubuntu:~/workspace/nginx-1.10.3$ sudo make

weijl@weijl-ubuntu:~/workspace/nginx-1.10.3$ sudo make install

開始測试验证

在浏览器中输入localhost:80/test,结果如图：

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