Dynamic upstream proxy_pass

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:


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

Best regards,

My bad, in one location I forgot to remove port, that is why nginx tried
resolve upstream as hostname.

Posted at Nginx Forum: