nginx-cdn.conf

# author: https://www.linkedin.com/in/abhishekdujari
proxy_cache_path /tmp/cache levels=1:2 keys_zone=my_cache:100m max_size=1g inactive=60m;
### Explanation ### 
# proxy_cache_path: where the chached files will be stored. Dont use ramdisk here, see keys_zone.
# levels: How many directories deep will the cache files be split.
# keys_zone: this is the memory space used for cache. key_zone must be unique for each host even
# though they can share the same proxy_cache_path. this uses shm internally. 1mb = 8000 cache keys
# max_size: maximum disk space for this cache. Note: YMMV.
# inactive: invalidate the cache automatically and purge regardless of freshness. YMMV

server {


    listen      80;
    listen [::]:80;
    #edit your actual site name
    server_name www.example.com;

   location / {
      # what is your origin IP/hostname, not your actual site but a resolver.
      proxy_pass http://origin.example.com;
      # what hostname does the webserver responds to.
      proxy_set_header Host $host;
      # if you were using Akamai, you can set a custom header to do same `True-Client-IP`
      # if you used Cloudflare use CF-Connecting-IP. Some plugins and libraries recognize this header as True remote ip.
      proxy_set_header  True-Client-IP  $remote_addr;
    }

   # Cache all static files, errors as well!
   location ~* .(jpg|png|gif|jpeg|webp|css|mp3|wav|swf|mov|doc|pdf|xls|ppt|docx|pptx|xlsx)$ {

    proxy_cache_key         "$scheme$host$request_uri";
    proxy_cache_revalidate on;
    proxy_cache_valid   200 301  7d;
    proxy_cache_valid   302      10s;
    proxy_cache_min_uses  2;
    proxy_cache_use_stale error timeout invalid_header http_500 http_502 http_503;
    proxy_ignore_headers Cache-Control;
    proxy_ignore_headers Expires;
    proxy_cache_valid any 30m;
    proxy_set_header Host $host;
    proxy_set_header  True-Client-IP  $remote_addr;
    proxy_cache my_cache;

    # You can specify an alternate origin for static files and also turn access_log off.
    proxy_pass http://origin.example.com;

    }


}