nginx-link-function

The Application dynamic linking with Nginx

Table of Contents

• Introduction
• How it works
• Usage
• Installation
• Sample Application Development
• Test
• Wiki
• Support
• Copyright & License

Introduction

nginx-link-function is a nginx module which provides dynamic linking to your application in server context and call the function of your application in location directive.You could direct link your C/C++ application (or any other which accept dynamic linking) to nginx server.

How it works

Usage

# nginx.conf

server {
  listen 8888;
  ...
  ngx_link_func_lib "/path/to/your/libcfuntest.so";
  ...
  ...
  location = /testCFunGreeting {
      ngx_link_func_call "my_app_simple_get_greeting"; 
  }
}

server {
  listen 8989;
  aio threads;
  ...
  ngx_link_func_lib "/path/to/your/libcfuntest.so"; # sharing data memory with server 1 if the path are same with server 1
  ...
  ...
  location = /testCFunGreeting {
      ngx_link_func_call "my_app_simple_get_greeting" 
  }
}

server {
  listen 8999;
  aio threads;
  ...
  ngx_link_func_lib "/path/to/your/libcfuntest2.so"; # another application
  ...
  ...
  location = /testPost {
      add_header Allow "GET, POST, HEAD" always;
      if ( $request_method !~ ^(POST)$ ) {
        return 405;
      }
      ngx_link_func_call "my_2nd_app_simple_get_token";
  }
}

server {
  listen 9888;
  aio threads;
  ...
  ## Download application from cloud repo e.g. ngx_link_func_download_link_lib <download_link> <dest_link_file>
  ngx_link_func_download_link_lib "http://abc.com/repos/libcfuntest.so" "/etc/nginx/libcfuntest3.so"
  ...
  ...
  location = /testPost {
      add_header Allow "GET, POST, HEAD" always;
      if ( $request_method !~ ^(POST)$ ) {
        return 405;
      }
      ngx_link_func_call "my_3rd_app_simple_get_token";
  }
}

server {
  listen 9898;
  aio threads;
  ...
  ## Download application from cloud repo with extra header e.g. ngx_link_func_download_link_lib <download_link> <headers> <dest_link_file>
  ngx_link_func_download_link_lib "https://abc.com/repos/libcfuntest.so" "Accept-Language:en_US\r\nAuthorization:Bearer KA.eyJ2ZXJzaadlasdlaldhjHJ2h3ldjklsjaklcjkljasdklcmasaskdaJxdkL3ftjM\r\n" "/etc/nginx/libcfuntest4.so"
  ...
  ...
  location = /testPost {
      add_header Allow "GET, POST, HEAD" always;
      if ( $request_method !~ ^(POST)$ ) {
        return 405;
      }
      ngx_link_func_call "my_other_app_simple_get_token";
  }
}

Installation

wget 'http://nginx.org/download/nginx-1.10.3.tar.gz'
tar -xzvf nginx-1.10.3.tar.gz
cd nginx-1.10.3/

./configure --add-module=/path/to/nginx-link-function

make -j2
sudo make install

ngx_link_func_module.h header not found when configure

When first time configure this project, I purposely do not include this header, you may need to install it to your c header file as this header file need to share with your .so application as well.

Example of installing header

install -m 644 /path/to/nginx-link-function/src/ngx_link_func_module.h /usr/local/include/

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Interface that expose to client application

This is the interface that you can use to get more details from nginx server, it all inside the ngx_link_func_module.h.

#define ngx_link_func_content_type_plaintext "text/plain"
#define ngx_link_func_content_type_html "text/html; charset=utf-8"
#define ngx_link_func_content_type_json "application/json"
#define ngx_link_func_content_type_jsonp "application/javascript"
#define ngx_link_func_content_type_xformencoded "application/x-www-form-urlencoded"

typedef struct {
  char *req_args; // Uri Args
  u_char *req_body; // Request Body
  size_t req_body_len; // length of body
  void *shared_mem;

  /* internal */
  void* __r__;
  void* __pl__;
  void* __log__;
} ngx_link_func_ctx_t;

extern void ngx_link_func_log_debug(ngx_link_func_ctx_t *ctx, const char* msg);
extern void ngx_link_func_log_info(ngx_link_func_ctx_t *ctx, const char* msg);
extern void ngx_link_func_log_warn(ngx_link_func_ctx_t *ctx, const char* msg);
extern void ngx_link_func_log_err(ngx_link_func_ctx_t *ctx, const char* msg);
extern u_char* ngx_link_func_get_header(ngx_link_func_ctx_t *ctx, const char*key);
extern void* ngx_link_func_get_query_param(ngx_link_func_ctx_t *ctx, const char *key);
extern void* ngx_link_func_palloc(ngx_link_func_ctx_t *ctx, size_t size);
extern void* ngx_link_func_pcalloc(ngx_link_func_ctx_t *ctx, size_t size);

extern void ngx_link_func_write_resp(
    ngx_link_func_ctx_t *ctx,
    uintptr_t status_code,
    const char* status_line,
    const char* content_type,
    const char* resp_content,
    size_t resp_len
);


// Shared Memory and Cache Scope
extern void ngx_link_func_shmtx_lock(void *shared_mem);
extern void ngx_link_func_shmtx_unlock(void *shared_mem);
extern void* ngx_link_func_shm_alloc(void *shared_mem, size_t size);
extern void ngx_link_func_shm_free(void *shared_mem, void *ptr);
extern void* ngx_link_func_cache_get(void *shared_mem, const char* key);
extern void* ngx_link_func_cache_put(void *shared_mem, const char* key, void* value);
extern void* ngx_link_func_cache_new(void *shared_mem, const char* key, size_t size);
extern void ngx_link_func_cache_remove(void *shared_mem, const char* key);

Interface break down details

malloc/calloc from nginx pool

void* ngx_link_func_palloc(ngx_link_func_ctx_t *ctx, size_t size);
void* ngx_link_func_pcalloc(ngx_link_func_ctx_t *ctx, size_t size);

get the request header parameter from

extern u_char* ngx_link_func_get_header(ngx_link_func_ctx_t *ctx, const char*key);

get the uri args

ctx->req_args;

get the query parameter

extern void* ngx_link_func_get_query_param(ngx_link_func_ctx_t *ctx, const char *key);

get the request body

ctx->req_body;

get the request body length

ctx->req_body_len;

loggin to nginx server

extern void ngx_link_func_log_debug(ngx_link_func_ctx_t *ctx, const char* msg);
extern void ngx_link_func_log_info(ngx_link_func_ctx_t *ctx, const char* msg);
extern void ngx_link_func_log_warn(ngx_link_func_ctx_t *ctx, const char* msg);
extern void ngx_link_func_log_err(ngx_link_func_ctx_t *ctx, const char* msg);

Response out

extern void ngx_link_func_write_resp(
    ngx_link_func_ctx_t *ctx,
    uintptr_t status_code, // Status code
    const char* status_line, // Status line
    const char* content_type, // Response content type
    const char* resp_content, // Response content
    size_t resp_len // Response content length
);

Sample Application Development

Feel free to clone a sample project at

Simple Project with cmake

link function google direction linkfunc-jwt-auth

#include <stdio.h>
#include <ngx_link_func_module.h>

/*** build the program as .so library and copy to the preferred place for nginx to link this library ***/
/*** gcc -shared -o libcfuntest.so -fPIC cfuntest.c ***/
/*** cp libcfuntest.so /etc/nginx/ ***/

int is_service_on = 0;

void ngx_link_func_init_cycle(ngx_link_func_cycle_t* cycle) {
    ngx_link_func_cyc_log(info, cycle, "%s", "starting application");

    is_service_on=1;
}

void my_app_simple_get_greeting(ngx_link_func_ctx_t *ctx) {
    ngx_link_func_log_info(ctx, "Calling back and log from my_app_simple_get");

    ngx_link_func_write_resp(
        ctx,
        200,
        "200 OK",
        "text/plain",
        "greeting from ngx_link_func testing",
        sizeof("greeting from ngx_link_func testing")-1
    );
}

void my_app_simple_get_args(ngx_link_func_ctx_t *ctx) {
    ngx_link_func_log_info(ctx, "Calling back and log from my_app_simple_get_args");

    if(ctx->req_args) {
        ngx_link_func_write_resp(
            ctx,
            200,
            "200 OK",
            "text/plain",
            ctx->req_args,
            strlen(ctx->req_args)
        );
    } else {
        ngx_link_func_write_resp(
            ctx,
            204,
            "",
            "text/plain",
            NULL,
            0
        );
    }
}

void my_app_simple_get_token_args(ngx_link_func_ctx_t *ctx) {
    ngx_link_func_log_info(ctx, "Calling back and log from my_app_simple_get_token_args");

    char * tokenArgs = (char*)ngx_link_func_get_query_param(ctx, "token");
    if (! tokenArgs) {
        ngx_link_func_write_resp(
            ctx,
            401,
            "401 unauthorized",
            "text/plain",
            "Token Not Found",
            sizeof("Token Not Found")-1
        );
    } else {
        ngx_link_func_write_resp(
            ctx,
            401,
            "401 unauthorized",
            "text/plain",
            tokenArgs,
            strlen(tokenArgs)
        );
    }
}

void my_app_simple_post(ngx_link_func_ctx_t *ctx) {
    ngx_link_func_log_info(ctx, "Calling back and log from my_app_simple_post");

    ngx_link_func_write_resp(
        ctx,
        202,
        "202 Accepted and Processing",
        "text/plain",
        NULL,
        0
    );
}



void my_app_simple_get_no_resp(ngx_link_func_ctx_t *ctx) {
    ngx_link_func_log_info(ctx, "Calling back and log from my_app_simple_get_no_resp");

    //  return 404 
}

void ngx_link_func_exit_cycle(ngx_link_func_cycle_t* cyc) {
    ngx_link_func_cyc_log(info, cyc, "%s\n", "Shutting down/reloading the Application");

    is_service_on = 0;
}

Noted:

The function init and exit cycle are reserved function when started the nginx, it will call init cycle function, when stop/reload nginx, it will call exit cycle function.

void ngx_link_func_init_cycle(ngx_link_func_cycle_t* cyc){}
void ngx_link_func_exit_cycle(ngx_link_func_cycle_t* cyc){}

references: The init and exit cycle hooks in application layer

Log Level

The log can be called, the logged message will be store where you config error log in nginx.conf

ngx_link_func_log_info(ctx, "This is info direct message");
ngx_link_func_log(info, ctx, "%s", "This is info with formatted message");
ngx_link_func_log_debug(ctx, "This is debug direct message");
ngx_link_func_log(debug, ctx, "%s", "This is debug with formatted message");

ngx_link_func_log_info(ctx, "%s", "This is info with formatted message"); // Wrong format
ngx_link_func_log_debug(ctx, "%s", "This is info with formatted message"); // Wrong format

provide ca-cert to download your app(.so)?? please embedded this in your nginx.conf's server context.

ngx_link_func_ca_cert "/etc/ssl/certs/ca-cert.crt"
ngx_link_func_download_link_lib "https://abc.com/repos/libcfuntest.so" "/etc/nginx/libcfuntest4.so"

provide ca-cert and extra header to download your app(.so)?? please embedded this in your nginx.conf's server context.

ngx_link_func_ca_cert "/etc/ssl/certs/ca-cert.crt"
ngx_link_func_download_link_lib "https://abc.com/repos/libcfuntest.so" "Accept-Language:en_US\r\nAuthorization:Bearer KA.eyJ2ZXJzaadlasdlaldhjHJ2h3ldjklsjaklcjkljasdklcmasaskdaJxdkL3ftjM\r\n" "/etc/nginx/libcfuntest4.so"

Test

It depends on nginx test suite libs, please refer test-nginx for installation.

cd /path/to/nginx-link-function
export PATH=/path/to/nginx-dirname:$PATH 
sudo prove -r t/

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Support

Please raise an issue and I will fixed it as soon as I can

Alternatively, you may email to [email protected]

Wiki

Check out wiki for more details

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Copyright & License

Copyright (c) 2018-2020, Taymindis [email protected]

This module is licensed under the terms of the BSD license.

All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

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