Instead of writing multiple server blocks repeatedly in configuration, we can simplified configuration using nginx map module
ie:
1 | map_hash_bucket_size 128; |
3 | map $http_host $backend_servers { |
5 | default www.example.com; |
6 | frontend.example2.com backend.example2.com |
7 | frontend.example3.com backend.example3.com |
8 | www.example.org backend.example.org |
11 | proxy_set_header X-Real-IP $remote_addr; |
12 | proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; |
13 | proxy_set_header Host $http_host; |
17 | proxy_pass http://$backend_servers |
source: taken from nginx mailinglist
