nginx模块开发入门（一） 快速编写一个模块

dog1888

1.首先按照nginx
参考http://running.iyunv.com/blog/326873
2.创建新模块目录

#mkdir ngx_module_echo


3.创建编译相关文件(config)
#vim ngx_module_echo/config

其内容为:
ngx_addon_name=ngx_module_echo
HTTP_MODULES="$HTTP_MODULES ngx_module_echo"
NGX_ADDON_SRCS="$NGX_ADDON_SRCS $ngx_addon_dir/ngx_module_echo.c"
CORE_LIBS="$CORE_LIBS "
#CORE_LIBS="$CORE_LIBS -lm"

ngx_addon_name一般设置为模块名称
HTTP_MODULES保持所有的HTTP模块名称，以空格符相连。用法有点类似于linux中得path，先给出之前的$HTTP_MODULES，然后在加上新增的MODULES
NGX_ADDON_SRCS指定新增模块的源代码，注意：如果使用了$ngx_addon_dir，它等价于在configure执行时--add-module=PATH中的PATH参数
4.创建源文件ngx_module_echo.c

#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_http.h>
static char* ngx_echo_readconf(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
static void* ngx_echo_create_loc_conf(ngx_conf_t *cf);
static char* ngx_echo_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child);
typedef struct {
ngx_str_t ecdata;
ngx_flag_t           enable;
} ngx_echo_loc_conf_t;
static ngx_command_t  ngx_echo_commands[] = {
{ ngx_string("echo"),
NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
ngx_echo_readconf,
NGX_HTTP_LOC_CONF_OFFSET,
offsetof(ngx_echo_loc_conf_t, ecdata),
NULL },
ngx_null_command
};

static ngx_http_module_t  ngx_echo_module_ctx = {
NULL,                          /* preconfiguration */
NULL,           /* postconfiguration */
NULL,                          /* create main configuration */
NULL,                          /* init main configuration */
NULL,                          /* create server configuration */
NULL,                          /* merge server configuration */
ngx_echo_create_loc_conf,  /* create location configuration */
ngx_echo_merge_loc_conf /* merge location configuration */
};

ngx_module_t  ngx_module_echo = {
NGX_MODULE_V1,
&ngx_echo_module_ctx, /* module context */
ngx_echo_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
};

static ngx_int_t
ngx_echo_handler(ngx_http_request_t *r)
{
printf("called:ngx_echo_handler\n");
ngx_int_t     rc;
ngx_buf_t    *b;
ngx_chain_t   out;
ngx_echo_loc_conf_t  *cglcf;
cglcf = ngx_http_get_module_loc_conf(r, ngx_module_echo);
if (!(r->method & (NGX_HTTP_GET|NGX_HTTP_HEAD))) {
return NGX_HTTP_NOT_ALLOWED;
}
if (r->headers_in.if_modified_since) {
return NGX_HTTP_NOT_MODIFIED;
}
r->headers_out.content_type.len = sizeof("text/html") - 1;
r->headers_out.content_type.data = (u_char *) "text/html";

r->headers_out.status = NGX_HTTP_OK;
r->headers_out.content_length_n = cglcf->ecdata.len;
if (r->method == NGX_HTTP_HEAD) {
rc = ngx_http_send_header(r);
if (rc == NGX_ERROR || rc > NGX_OK || r->header_only) {
return rc;
}
}
b = ngx_pcalloc(r->pool, sizeof(ngx_buf_t));
if (b == NULL) {
ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "Failed to allocate response buffer.");
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
out.buf = b;
out.next = NULL;

b->pos = cglcf->ecdata.data;
b->last = cglcf->ecdata.data+(cglcf->ecdata.len);
b->memory = 1;
b->last_buf = 1;
rc = ngx_http_send_header(r);
if (rc == NGX_ERROR || rc > NGX_OK || r->header_only) {
return rc;
}
return ngx_http_output_filter(r, &out);
}
static char *
ngx_echo_readconf(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
printf("called:ngx_echo_readconf\n");
ngx_http_core_loc_conf_t  *clcf;
clcf = ngx_http_conf_get_module_loc_conf(cf, ngx_http_core_module);
clcf->handler = ngx_echo_handler;
ngx_conf_set_str_slot(cf,cmd,conf);
return NGX_CONF_OK;
}

static void *
ngx_echo_create_loc_conf(ngx_conf_t *cf)
{
printf("called:ngx_echo_create_loc_conf\n");
ngx_echo_loc_conf_t  *conf;
conf = ngx_pcalloc(cf->pool, sizeof(ngx_echo_loc_conf_t));
if (conf == NULL) {
return NGX_CONF_ERROR;
}
conf->ecdata.len=0;
conf->ecdata.data=NULL;
conf->enable = NGX_CONF_UNSET;
return conf;
}
static char *
ngx_echo_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child)
{
printf("called:ngx_echo_merge_loc_conf\n");
ngx_echo_loc_conf_t *prev = parent;
ngx_echo_loc_conf_t *conf = child;
ngx_conf_merge_str_value(conf->ecdata, prev->ecdata, 10);
ngx_conf_merge_value(conf->enable, prev->enable, 0);
/**
if(conf->enable)
ngx_echo_init(conf);
*/
return NGX_CONF_OK;
return NGX_CONF_OK;
}


5.编译nginx
./configure --prefix=/usr/local/nginx --with-pcre=/root/pcre-8.33/ --with-http_stub_status_module  --with-http_realip_module  --add-module=/root/ngx_module_echo/ --with-debug
make
make install


6.修改nginx.conf

worker_processes  1;
daemon off;
master_process  off;
error_log  /tmp/error.log debug;
pid /tmp/nginx_demo.pid;
events {
worker_connections  1024;
}
http {
include         mime.types;
sendfile        on;
keepalive_timeout  65;
tcp_nodelay        on;
server {
listen   8100;
server_name  localhost;
access_log  /tmp/access.log;
error_log  /tmp/error.log debug;
location /hello {
echo "Hi,this is a demo module";
}
}
}


7.测试

#/usr/local/nginx/sbin/nginx -t
called:ngx_echo_create_loc_conf
called:ngx_echo_create_loc_conf
called:ngx_echo_create_loc_conf
called:ngx_echo_readconf
called:ngx_echo_merge_loc_conf
called:ngx_echo_merge_loc_conf
nginx: the configuration file /usr/local/nginx/conf/nginx.conf syntax is ok
nginx: configuration file /usr/local/nginx/conf/nginx.conf test is successful


8.运行
测试没有问题以后，我们就可以开始运行了

#/usr/local/nginx/sbin/nginx

然后通过浏览器进行访问
http://localhost:8100/hello
显示
Hi,this is a demo module
好了,大功告成,nginx模块版的hello world就到这里了;