Use nginx to proxy request to two different services? - nginx

Question

Goal: Stand up a service that will accept requests to
http://foo.com/a
and turn around and proxy that request to two different services
http://bar.com/b
http://baz.com/c
The background is that I'm using a service that can integrate with other 3rd party services by accepting post request, and then posting event callbacks to that 3rd party service via posting to a URL. Trouble is that it only supports a single URL in its configuration, so it becomes impossible to integrate more than one service this way.
I've looked into other services like webhooks.io (waaaay too expensive for a moderate amount of traffic) and reflector.io (beta - falls over with a moderate amount of traffic), but so far nothing meets my needs. So I started poking around at standing up my own service, and I'm hoping for as hands-off as possible. Feels like nginx ought to be able to do this...
I came across the following snippet which someone else classified as a bug, but feels like the start of what I want:
upstream apache {
server 1.2.3.4;
server 5.6.7.8;
}
...
location / {
proxy_pass http://apache;
}
Rather than round robin request to apache, that will apparently send the same request to both apache servers, which sounds promising. Trouble is, it sends it to the same path on both server. In my case, the two services will have different paths (/b and /c), and neither is the same path as the inbound request (/a)
So... Any way to specify a destination path on each server in the upstream configuration, or some other clever way of doing this?

Answer 1

You can create local servers. Local servers proxy_pass add the different path (b,c).
upstream local{
server 127.0.0.1:8000;
server 127.0.0.1:8001;
}
location / {
proxy_pass http://local ;
}
server {
listen 8000;
location / {
proxy_pass http://1.2.3.4/b;
}
server {
listen 8001;
location / {
proxy_pass http://5.6.7.8/c;
}