Location header rewritten coming from cache

[AlexClineBB]

We're running into an issue where the Location header sent in a 302 request is getting changed depending on if the response is a cache MISS or HIT. On misses, a relative URL is returned (as desired). On hits, an absolute URL is returned despite a relative URL being saved to the cache.

The srcache configuration:

srcache_response_cache_control on;
srcache_default_expire 0s;

set $key $scheme$host$request_uri$bb_accept$requested_with$cookie__bb_locale$cookie__bb_country;
set_escape_uri $escaped_key $key;

srcache_fetch GET /redis $key;
srcache_store PUT /redis2 key=$escaped_key&exptime=$srcache_expire;

When submitting a request that returns 302 response that is a cache MISS, the Location header is relative.

curl -i -H "Host: foobar.example.com" localhost/categories/non-gmo
HTTP/1.1 302 Moved Temporarily
Server: openresty
Date: Thu, 05 Feb 2015 21:03:42 GMT
Content-Type: text/plain; charset=UTF-8
Content-Length: 64
Connection: keep-alive
Vary: X-HTTP-Method-Override, Accept
Cache-Control: public, max-age=3600
Location: /categories/non-gmo-2/products

127.0.0.1 - - [05/Feb/2015:20:59:49 +0000] "GET /categories/non-gmo HTTP/1.1" 302 64 "-" "curl/7.35.0" 0.003 0.001 - - foobar.example.com public, max-age=3600 - MISS

We can see that the response is now cached in our redis instance:

redis-cache:6379> GET foobar.example:938810f609eeeddf722e3ac68ecca339
"HTTP/1.1 302 Moved Temporarily\r\nContent-Type: text/plain; charset=UTF-8\r\nVary: X-HTTP-Method-Override, Accept\r\nCache-Control: public, max-age=3600\r\nLocation: /categories/non-gmo-2/products\r\n\r\nMoved Temporarily. Redirecting to /categories/non-gmo-2/products"

Subsequent requests that generate a cache HIT are returned with a FQDN in the Location header rather than the relative path:

curl -i -H "Host: foobar.example.com" localhost/categories/non-gmo
HTTP/1.1 302 Moved Temporarily
Server: openresty
Date: Thu, 05 Feb 2015 21:08:15 GMT
Content-Type: text/plain; charset=UTF-8
Content-Length: 64
Location: http://foobar.example.com/categories/non-gmo-2/products
Connection: keep-alive
Vary: X-HTTP-Method-Override, Accept
Cache-Control: public, max-age=3600

127.0.0.1 - - [05/Feb/2015:21:08:15 +0000] "GET /categories/non-gmo HTTP/1.1" 302 64 "-" "curl/7.35.0" 0.003 - - - foobar.example.com - - HIT

I've tried using proxy_redirect off; in the nginx configuration, but it doesn't seem to have an affect on the responses coming from srcache.

If I use srcache_store_statuses 200; to explicitly not cache redirect pages, responses include relative Location headers and aren't cached. This is less desirable in our environment, but is a temporary workaround.

Can you confirm that srcache rewriting the Location header being returned in cached responses? Is there an option for disabling the behavior we're experiencing?

Thank you.

[agentzh]

@AlexClineBB Thank you for the bug report! Just fixed in git master. Will you try it out on your side?