Nginx output through different interfaces

Sometime we faced with different challenges and most important think it implements that as soon is possible and more elegance.

Imagine a situation, we have just only one interface for incoming requests and you need to use other interfaces just for output traffic.

Nginx have it out of box.

Scheme like that:

->  192.168.1.99
X   192.168.1.10 ->
X   192.168.1.20 ->
X   192.168.1.30 ->

• Usually nginx exists module as ngx_http_split_clients_module
• Configure nginx add block with split_clients

split_clients "$request_uri$remote_port" $split_ip {
    33%    192.168.1.10;
    33%    192.168.1.20;
    33%    192.168.1.30;
    *      192.168.1.10;
}

location / {
   proxy_bind $split_ip;
   ...
}

• Check it

Just run tcpdump and check output traffic to backend`

# tcpdump -npi any host 192.168.1.30