开发Nginx模块Helloworld

本文是对《深入理解Nginx》一书中的实例进行实战时的记录。

1模块目录结构

my_test_module/

├── config

└── ngx_http_mytest_module.c

1.1配置文件

config文件内容如下：

ngx_addon_name=ngx_http_mytest_module

HTTP_MODULES="$HTTP_MODULESngx_http_mytest_module"

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

1.2模块源码

ngx_http_mytest_module.c中的内容如下：

#include <ngx_config.h>  
#include <ngx_core.h>  
#include <ngx_http.h>  
  
static ngx_int_t ngx_http_mytest_handler(ngx_http_request_t *r)  
{  
    // Only handle GET/HEAD method  
    if (!(r->method & (NGX_HTTP_GET | NGX_HTTP_HEAD))) {  
        return NGX_HTTP_NOT_ALLOWED;  
    }  
  
    // Discard request body  
    ngx_int_t rc = ngx_http_discard_request_body(r);  
    if (rc != NGX_OK) {  
        return rc;  
    }  
  
    // Send response header  
    ngx_str_t type = ngx_string("text/plain");  
    ngx_str_t response = ngx_string("Hello World!!!");  
    r->headers_out.status = NGX_HTTP_OK;  
    r->headers_out.content_length_n = response.len;  
    r->headers_out.content_type = type;  
      
    rc = ngx_http_send_header(r);  
    if (rc == NGX_ERROR || rc > NGX_OK || r->header_only) {  
        return rc;  
    }  
  
    // Send response body  
    ngx_buf_t *b;  
    b = ngx_create_temp_buf(r->pool, response.len);  
    if (b == NULL) {  
        return NGX_HTTP_INTERNAL_SERVER_ERROR;  
    }  
    ngx_memcpy(b->pos, response.data, response.len);  
    b->last = b->pos + response.len;  
    b->last_buf = 1;  
  
    ngx_chain_t out;  
    out.buf = b;  
    out.next = NULL;  
    return ngx_http_output_filter(r, &out);  
}  
  
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;  
}  
  
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,  
        NGX_HTTP_LOC_CONF_OFFSET,  
        0,  
        NULL  
    },  
    ngx_null_command      
};  
  
static ngx_http_module_t ngx_http_mytest_module_ctx = {  
    NULL,  
    NULL,  
    NULL,  
    NULL,  
    NULL,  
    NULL,  
    NULL,  
    NULL  
};  
  
ngx_module_t ngx_http_mytest_module = {  
    NGX_MODULE_V1,  
    &ngx_http_mytest_module_ctx,  
    ngx_http_mytest_commands,  
    NGX_HTTP_MODULE,  
    NULL,  
    NULL,  
    NULL,  
    NULL,  
    NULL,  
    NULL,  
    NULL,  
    NGX_MODULE_V1_PADDING  
};  

 

2编译运行

2.1编译Nginx和我的模块

Nginx依赖GCC, PCRE等，所以需要预先安装这些依赖包。之后下载nginx-1.4.2.tar.gz源码包并解压：

         tarzxvf nginx-1.4.2.tar.gz

         cdnginx-1.4.2

         ./configure–add-module=/usr/local/src/my_test_module

         make

         makeinstall

 

从make编译时的日志也能看到我们的模块被编译进Nginx内核了：

2.2启用我的模块

Nginx默认被安装到/usr/local/nginx下了，在其/conf/nginx.conf配置文件中添加一段server配置来启用我们的模块：

         server{

                   listen80;

                   server_namemytest.com

                   location/ {

                            mytest;

                   }

         }

2.3运行效果

将域名mytest.com添加到Host中，指向Nginx所在机器，然后访问http://mytest.com就能看到效果了：

3模块源码解释

（未完待续）