Been playing with this for 2 days.

proxy_pass is working correctly but the proxy_cache_path remains empty whatever I make.


Here's the source I use for tests:
root@NC-PH-0657-10:/etc/nginx/snippets# curl -X GET -I http://www.kuriyama-truck.com/images/parts/13375/thumbnail_0/1_1.jpg
HTTP/1.1 200 OK
Date: Sat, 19 Mar 2016 18:15:16 GMT
Server: Apache/2.4.16 (Amazon) PHP/5.6.17
Last-Modified: Thu, 10 Mar 2016 05:01:30 GMT
ETag: "d0f3-52daab51fbe80"
Accept-Ranges: bytes
Content-Length: 53491
Content-Type: image/jpeg

Now here's the response from the nginx:
root@NC-PH-0657-10:/etc/nginx/snippets# curl -X GET -I http://dev.ts-export.com/kuriyamacache/images/parts/13375/thumbnail_0/1_1.jpg
HTTP/1.1 200 OK
Server: nginx
Date: Sat, 19 Mar 2016 18:14:46 GMT
Content-Type: image/jpeg
Content-Length: 53491
Connection: keep-alive
Expires: Sun, 19 Mar 2017 18:14:46 GMT
Cache-Control: max-age=31536000
Cache-Control: public
X-Cache-Status: MISS
Accept-Ranges: bytes

Here are the request headers from my browser:
GET /kuriyamacache/images/parts/13375/thumbnail_1/1_1.jpg HTTP/1.1
Host: dev.ts-export.com
Connection: keep-alive
Cache-Control: max-age=0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.87 Safari/537.36
DNT: 1
Accept-Encoding: gzip, deflate, sdch
Accept-Language: fr-CA,fr;q=0.8,en-US;q=0.6,en;q=0.4,ja;q=0.2,de;q=0.2
Cookie: PRUM_EPISODES=s=1458412951203

Part of my setup:

proxy_cache_path /tmp/nginx/dev levels=1:2 keys_zone=my_zone:10m max_size=10g inactive=60m use_temp_path=off;

server {

set $rule_3 0;
set $rule_4 0;
set $rule_5 0;
set $rule_8 0;
set $rule_9 0;

server_name dev.ts-export.com;
listen 80;
listen [::]:80;

root /home/tsuchi/public_html;

if ($reject_those_args) {
return 403;
}

include snippets/filters.conf;

error_page 404 /404.html;

if ($request_uri ~ "^/index.(php|html?)$" ) {
return 301 $scheme://dev.ts-export.com;
}


# no SSL for IE6-8 on XP and Android 2.3
if ($scheme = https) {
set $rule_8 1$rule_8;
}
if ($http_user_agent ~ "MSIE (6|7|8).*Windows NT 5|Android 2\.3"){
set $rule_8 2$rule_8;
}
if ($rule_8 = "210"){
return 301 http://dev.ts-export.com$request_uri;
}


location = / {
allow all;
}

location = /robots.txt {
add_header X-Robots-Tag noindex;
}


location '/.well-known/acme-challenge' {
default_type "text/plain";
root /tmp/letsencrypt-auto;
}

include snippets/proxyimg.conf;

location / {
try_files $uri $uri/ @rewrites;
allow all;
}
(...)
}

Contents of proxyimg.conf:

location ^~ /kuriyamacache {
expires 1y;
access_log off;
log_not_found off;
resolver 127.0.0.1;

proxy_pass http://www.kuriyama-truck.com/;

proxy_cache my_zone;
proxy_cache_key "$scheme$request_method$host$request_uri";
proxy_buffering on;

proxy_cache_valid 200 301 302 60m;
proxy_cache_valid 404 1m;
proxy_cache_use_stale error timeout http_500 http_502 http_503 http_504;
proxy_cache_revalidate on;
proxy_cache_lock on;

proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

proxy_ignore_headers X-Accel-Redirect X-Accel-Expires X-Accel-Limit-Rate X-Accel-Buffering X-Accel-Charset Set-Cookie Cache-Control Vary Expires;

proxy_pass_header ETag;
proxy_hide_header Cache-Control;

add_header Cache-Control "public, max-age=31536000";
add_header X-Cache-Status $upstream_cache_status;

}