NGINX Destination IP recovery module for stream and http

This dynamic module recovers original IP address and port number of the destination packet. It is used by nginmesh sidecar where all outgoing traffic is redirect to a single port using iptable mechanism

iptables -t nat -A PREROUTING -i eth1 -p tcp --dport 80 -j REDIRECT --to-ports 80
iptables -t nat -A PREROUTING -i eth1 -p tcp --dport 443 -j REDIRECT --to-ports 443

Dependencies

This module uses Linux getsockopt socket API.

Compatibility

nginx 1.18.0
openresty 1.19.3.1

Synopsis

load_module "modules/ngx_http_nginmesh_dest_module.so";

http {
    server {
        #  use iptable to capture all outgoing traffic.  see Istio design document
        listen 80;

        # turn on module for this server
        # original IP destination and port is set to variable $nginmesh_dest
        # ex: 10.31.242.228:80
        nginmesh_dest on;

        # variable can be used in valid config directive
        proxy_pass $nginmesh_dest;
    }
}

Embedded Variables

The following embedded variables are provided:

nginmesh_dest
- Original IP address and port in the format: <address>:<port>

Directives

nginmesh_dest

-	-
Syntax	nginmesh_dest <on\|off>
Default	off
Context	stream, http, server

Description: Enables or disables the nginmesh_dest module

Installation

Clone the git repository

foo@bar:~$ git clone https://github.com/chenwei791129/ngx-nginmesh-dest.git

Build the dynamic module

foo@bar:~$ curl -L "https://openresty.org/download/openresty-1.19.3.1.tar.gz" -o openresty.tar.gz \
&& tar -xzvf openresty.tar.gz \
&& rm -f openresty.tar.gz \
&& cd openresty-1.19.3.1
foo@bar:~$ ./configure --prefix=/usr/local/openresty/nginx --with-cc-opt='-O2 -DNGX_LUA_ABORT_AT_PANIC -I/usr/local/openresty/zlib/include -I/usr/local/openresty/pcre/include -I/usr/local/openresty/openssl111/include' --with-ld-opt='-Wl,-rpath,/usr/local/openresty/luajit/lib -L/usr/local/openresty/zlib/lib -L/usr/local/openresty/pcre/lib -L/usr/local/openresty/openssl111/lib -Wl,-rpath,/usr/local/openresty/zlib/lib:/usr/local/openresty/pcre/lib:/usr/local/openresty/openssl111/lib' --with-pcre-jit --with-stream --with-stream_ssl_module --with-stream_ssl_preread_module --with-http_v2_module --without-mail_pop3_module --without-mail_imap_module --without-mail_smtp_module --with-http_stub_status_module --with-http_realip_module --with-http_addition_module --with-http_auth_request_module --with-http_secure_link_module --with-http_random_index_module --with-http_gzip_static_module --with-http_sub_module --with-http_dav_module --with-http_flv_module --with-http_mp4_module --with-http_gunzip_module --with-threads --with-stream --with-debug --with-http_ssl_module --add-dynamic-module=../ngx-stream-nginmesh-dest/module
foo@bar:~$ make && make install