Nginx proxy_pass with variables and redirect

Question

It seems that Nginx can't support redirects when proxy_pass is set to variable. Is there a way to achieve this functionality e.g. somehow chain servers or other workaround? What is the reason why this is not supported?

.conf is:

proxy_pass $var;
proxy_redirect  default;

Error message I get is:

nginx: [emerg] "proxy_redirect default" cannot be used with "proxy_pass" directive with variables

Answer 1

You can work around this problem by specifying the full redirect statement instead of using the "default" option.

From the nginx documentation:

The default replacement specified by the default parameter uses the parameters of the location and proxy_pass directives. Hence, the two configurations below are equivalent:

location /one/ {
    proxy_pass     http://upstream:port/two/;
    proxy_redirect default;
location /one/ {
    proxy_pass     http://upstream:port/two/;
    proxy_redirect http://upstream:port/two/ /one/;

So to replace the "default" directive, you use the value of "proxy_pass" as the first argument for "proxy_redirect", and use the value of "location" for the second.

Answer 2

I once had the same issue and what saved me was Nginx's resolver module

try to add:

    resolver 8.8.8.8;

before the proxy_pass line. It should allow you to work with variables.

Also have a look at a similar question.