nginxOSMTileProxy

proxy_cache_path /var/www/cache/osm levels=1:2 keys_zone=osm-tiles:100m max_size=50g inactive=7d;
	location /osm/ {
		access_log /var/log/nginx/tiles_access.log combined;
		error_log /var/log/nginx/tiles_error.log info;
		expires 7d;
		proxy_cache osm-tiles;
		proxy_cache_key "$request_uri";
		proxy_cache_use_stale error timeout http_500 http_502 http_503 http_504;
		proxy_cache_lock on; # if race cond, only one request goes to OSM server
		proxy_cache_valid 200 302 7d;
		proxy_cache_valid 404 1m;
		proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
		proxy_set_header Host $http_host;
		proxy_pass http://tile.openstreetmap.org/; # don't need [abc] since no browser limitation
	}