nginx: How can I set proxy_* directives only for matching URIs?
- by Artem Russakovskii
I've been at this for hours and I can't figure out a clean solution.
Basically, I have an nginx proxy setup, which works really well, but I'd like to handle a few urls more manually. Specifically, there are 2-3 locations for which I'd like to set proxy_ignore_headers to Set-Cookie to force nginx to cache them (nginx doesn't cache responses with Set-Cookie as per http://wiki.nginx.org/HttpProxyModule#proxy_ignore_headers).
So for these locations, all I'd like to do is set proxy_ignore_headers Set-Cookie;
I've tried everything I could think of outside of setting up and duplicating every config value, but nothing works.
I tried:
Nesting location directives, hoping the inner location which matches on my files would just set this value and inherit the rest, but that wasn't the case - it seemed to ignore anything set in the outer location, most notably proxy_pass and I end up with a 404).
Specifying the proxy_cache_valid directive in an if block that matches on $request_uri, but nginx complains that it's not allowed ("proxy_cache_valid" directive is not allowed here).
Specifying a variable equal to "Set-Cookie" in an if block, and then trying to set proxy_cache_valid to that variable later, but nginx isn't allowing variables for this case and throws up.
It should be so simple - modifying/appending a single directive for some requests, and yet I haven't been able to make nginx do that.
What am I missing here?
Is there at least a way to wrap common directives in a reusable block and have multiple location blocks refer to it, after adding their own unique bits?
Thank you.
Just for reference, the main location / block is included below, together with my failed proxy_ignore_headers directive for a specific URI.
location / {
# Setup var defaults
set $no_cache "";
# If non GET/HEAD, don't cache & mark user as uncacheable for 1 second via cookie
if ($request_method !~ ^(GET|HEAD)$) {
set $no_cache "1";
}
if ($http_user_agent ~* '(iphone|ipod|ipad|aspen|incognito|webmate|android|dream|cupcake|froyo|blackberry|webos|s8000|bada)') {
set $mobile_request '1';
set $no_cache "1";
}
# feed crawlers, don't want these to get stuck with a cached version, especially if it caches a 302 back to themselves (infinite loop)
if ($http_user_agent ~* '(FeedBurner|FeedValidator|MediafedMetrics)') {
set $no_cache "1";
}
# Drop no cache cookie if need be
# (for some reason, add_header fails if included in prior if-block)
if ($no_cache = "1") {
add_header Set-Cookie "_mcnc=1; Max-Age=17; Path=/";
add_header X-Microcachable "0";
}
# Bypass cache if no-cache cookie is set, these are absolutely critical for Wordpress installations that don't use JS comments
if ($http_cookie ~* "(_mcnc|comment_author_|wordpress_(?!test_cookie)|wp-postpass_)") {
set $no_cache "1";
}
if ($request_uri ~* wpsf-(img|js)\.php) {
proxy_ignore_headers Set-Cookie;
}
# Bypass cache if flag is set
proxy_no_cache $no_cache;
proxy_cache_bypass $no_cache;
# under no circumstances should there ever be a retry of a POST request, or any other request for that matter
proxy_next_upstream off;
proxy_read_timeout 86400s;
# Point nginx to the real app/web server
proxy_pass http://localhost;
# Set cache zone
proxy_cache microcache;
# Set cache key to include identifying components
proxy_cache_key $scheme$host$request_method$request_uri$mobile_request;
# Only cache valid HTTP 200 responses for this long
proxy_cache_valid 200 15s;
#proxy_cache_min_uses 3;
# Serve from cache if currently refreshing
proxy_cache_use_stale updating timeout;
# Send appropriate headers through
proxy_set_header Host $host;
# no need for this proxy_set_header X-Real-IP $remote_addr;
# no need for this proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
# Set files larger than 1M to stream rather than cache
proxy_max_temp_file_size 1M;
access_log /var/log/nginx/androidpolice-microcache.log custom;
}
