nginx proxy_pass url with GET params conditionally - nginx

Question

I have a url http://foo.com/banana and I have another url http://foo.com/banana?a=1&b=2
I like that all /banana routes are handled by my local nginx, but I'd like any banana routes with GET params to be proxied to http://bar.com
so:
http://foo.com/banana -> http://foo.com/banana
http://foo.com/banana?a=1 -> (proxy) -> http://bar.com/banana?a=1
I should note this is not for production. I'm trying to redirect api calls to redirect to another server during development.
I've tried to do an 'if args' block but I can't do a proxy_pass in an if block.
I thought about doing a rewrite of:
http://foo.com/banana?a=1 -> http://foo.com/proxy?a=1
location /proxy {
proxy_pass http://bar.com;
}
But I don't have the right logic for above because bar.com is expecting the /banana route.
Any ideas?

Answer 1

Since this is not for production, you could stick with your original "if" solution. You only need to escape from the "if" block to be able to proxy_pass, which can be easily done with the traditional trick:
location /banana {
error_page 418 = #good_old_fallback;
if ($args) {
return 418;
}
}
location #good_old_fallback {
proxy_pass http://bar.com;
}
Your idea of using another location will also work, so if you prefer it better, you can go with something like this:
location /banana {
if ($args) {
rewrite ^/banana(.*)$ /proxy$1 last;
}
}
location /proxy {
internal;
rewrite ^/proxy(.*)$ /banana$1 break;
proxy_pass http://bar.com;
}