enable gzip compression with nginx

Question

I am trying to enable gzip compression for components of my website. I have ubuntu 11.04 server and nginx 1.2.
in my nginx configuration of the website, i have this

gzip             on;
#gzip_min_length  1000;
gzip_http_version 1.1;
gzip_vary on;
gzip_comp_level 6;
gzip_proxied any;
gzip_types text/plain text/html text/css application/json application/javascript application/x-javascript text/javascript text/xml application/xml application/rss+xml application/atom+xml application/rdf+xml;
#it was gzip_buffers 16 8k; 
gzip_buffers 128 4k; #my pagesize is 4
gzip_disable "MSIE [1-6].(?!.*SV1)";

and Yslow and google speed measures are advising me to use gzip to reduce transmission over network. now when i try to curl -I my_js_file i got

curl -I http://www.albawaba.com/sites/default/files/js/js_367664096ca6baf65052749f685cac7b.js
HTTP/1.1 200 OK
Server: nginx/1.2.0
Date: Sun, 14 Apr 2013 13:15:43 GMT
Content-Type: application/x-javascript
Content-Length: 208463
Connection: keep-alive
Last-Modified: Sun, 14 Apr 2013 10:58:06 GMT
Vary: Accept-Encoding
Expires: Thu, 31 Dec 2037 23:55:55 GMT
Cache-Control: max-age=315360000
Pragma: public
Cache-Control: public
Accept-Ranges: bytes

any idea of what i have done wrong or what shall i do to get compressed content?

Answer 1

As others have written, it's not enough to enable gzip compression in your server -- the client also needs to ask for it in its requests via the Accept-Encoding: gzip header (or a superset thereof). Modern browsers include this header automatically, but for curl you'll need to include one of the following in your command:

• -H "Accept-Encoding: gzip" : You should see the Content-Encoding: gzip header in the response (might need to output headers with curl's -v flag), as well as some seemingly garbled output for the content, the actual gzip stream.
• --compressed : You should still see Content-Encoding: gzip in the response headers, but curl knows to decompress the content before outputting it.