Forum: NGINX Dynamic upstream proxy_pass

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kay (Guest)
on 2014-04-09 10:19
(Received via mailing list)
I'm trying to set upstream names by variables, but nginx recognizes
variables as hostnames, not upstream names.

For example:
map $cookie_backend $proxy_host {
    default     'backend1';
    '1'             'backend2';
... ... ...
upstream backend1 {
    server backend123:8080;
    server backend124:8080;
... ... ...
upstream backend2 {
    server backend223:8080;
    server backend224:8080;
... ... ...
location / {
    proxy_pass      http://$proxy_host;

nginx returns error message:
2014/04/09 14:19:51 [error] 1085#0: *1128620 backend1 could not be
(3: Host not found) while sending to client, client:,
localhost, request: "GET / HTTP/1.1", host: "localhost"

Posted at Nginx Forum:,249142,249142#msg-249142
Makailol Charls (Guest)
on 2014-04-09 10:30
(Received via mailing list)

You need to use resolver directive in Nginx.
Also you need to set DNS entries for your backend hostname.

Best regards,
kay (Guest)
on 2014-04-09 11:04
(Received via mailing list)
My bad, in one location I forgot to remove port, that is why nginx tried
resolve upstream as hostname.

Posted at Nginx Forum:,249142,249145#msg-249145
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