content-type related nginx expires header - nginx

Question

Is it possible to set a content-type dependent expires header in nginx? I'm quite new to nginx and tried the following:
location ~ /files\.php$ {
...
if ($content_type = "text/css") {
add_header X-TEST1 123;
expires 7d;
}
if ($content_type = "image/png") {
add_header X-TEST2 123;
expires 30d;
}
if ($content_type = "application/javascript") {
add_header X-TEST3 123;
expires 1d;
}
#testing
if ($content_type != "text/css") {
add_header X-TEST4 abc;
}
#testing
if ($content_type = text/css) {
add_header X-TEST5 123;
}
}
But the only header added is "X-TEST4" on all requests.
I know about the other solution using file extension:
location ~* \.(ico|css|js|gif|jp?g|png)\?[0-9]+$
But it's not applicable for my application.

Answer 1

I think the code should be in location / { } instead of location ~ /files\.php$ { }...

Answer 2

Have you tried
$content_type ~= application/javascript
Also, make sure to read this:
http://wiki.nginx.org/IfIsEvil

Answer 3

If you have the lua module installed you could do something similar like this:
server {
location / {...}
header_filter_by_lua_block {
local cct = {} -- # cached content types
cct["text/css"] = true
cct["application/javascript"] = true
cct["application/x-javascript"] = true
cct["text/javascript"] = true
cct["image/jpeg"] = true
cct["image/png"] = true
cct["application/vnd.ms-fontobject"] = true
cct["application/font-woff"] = true
cct["application/x-font-truetype"] = true
cct["image/svg+xml"] = true
cct["application/x-font-opentype"] = true
if cct[ngx.header.content_type] ~= nil and ngx.header["expires"] == nil then
local now = os.time()
local expires = os.date("%a, %d-%b-%Y %H:%I:%S GMT", now+604800) -- # one week in seconds
ngx.header["expires"] = expires
end
}
}
Responses with the specified content-type will now get an expires-header.
When the response already has an expires-header the lua block will not touch the header.