I then realized that if that map were on my site, I'd have the same criticisms: the .js and .csv files wouldn't be sent across the wire gzipped.
The fix is to tell nginx to gzip a couple MIME types. Previously, I'd told nginx to gzip json. To zip additional content types, I had to modify
mime.types, both in
/etc/config on my machine.
The modified, expanded gzip section in
nginx.conf, in the main http block:
For MIME types, that same http block in nginx.conf also has:
include /etc/nginx/mime.types; default_type application/octet-stream;
In the types block in the
mime.types file, add an entry for csv: