Nginx send requests for missing images to backend - php

Question

I'm working on a website that has copies of the same images in various sizes e.g.
/images/200x100/someimage.jpg
/images/400x200/someimage.jpg
etc.
The images are served directly by Nginx and only php requests get passed to the fastcgi.
If an image can't be found I would like to pass the request to fastcgi so that I can see if we can generate a version of the image in the correct size and then return that.
I just can't get it working - if the image is missing I can get it to call the script I want (instead of just returning a 404) BUT it is just returning the source of the php script.
This is the relevant part of my conf file:
location ~ (^|/)\. {
return 404;
}
location /imgs {
location ~ \.php$ {return 403;}
}
#Static Contents
location ~* ^.+.(jpg|jpeg|png|gif|bmp)$ {
try_files $uri /$uri #backend;
add_header Pragma "public";
add_header Cache-Control "public";
expires 1y;
access_log off;
log_not_found off;
}
# Static Contents
location ~* ^.+.(ico|css|zip|tgz|gz|rar|bz2|doc|xls|exe|pdf|ppt|txt|tar|mid|midi|wav|bmp|rtf|js|eot|woff|svg|htc)$ {
add_header Pragma "public";
add_header Cache-Control "public";
expires 1y;
access_log off;
log_not_found off;
}
location / {
# Check if a file exists, or route it to index.php.
try_files $uri $uri/ /index.php?$query_string;
}
location ~\.php$ {
try_files $uri =404;
fastcgi_pass unix:/dev/shm/apache-php.sock;
fastcgi_index index.php;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
include /etc/nginx/fastcgi_params;
}
location #backend {
#return 410;
rewrite ^(.*)$ /image.php?url=$1;
fastcgi_pass unix:/dev/shm/apache-php.sock;
fastcgi_index index.php;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
include /etc/nginx/fastcgi_params;
}
A missing image will then pass into the location #backend but I can't pass the $uri to a script.
I've been through all kinds of variations what am I doing wrong? Any suggestions gratefully appreciated! Thanks.
Update
I've got this working in another VM perfectly (I copied the backend block and images blocks into the other conf file) - the only difference is that the one that works is using Apache instead of fastcgi.

Answer 1

The problem was a just a typo.
I was trying to rewrite to /image.php it should have been /images.php
The working version of the above conf file is as follows:
location ~ (^|/)\. {
return 404;
}
location /imgs {
location ~ \.php$ {return 403;}
}
#Static Contents
location ~* ^.+.(jpg|jpeg|png|gif|bmp)$ {
try_files $uri /$uri #backend;
add_header Pragma "public";
add_header Cache-Control "public";
expires 1y;
access_log off;
log_not_found off;
}
# Static Contents
location ~* ^.+.(ico|css|zip|tgz|gz|rar|bz2|doc|xls|exe|pdf|ppt|txt|tar|mid|midi|wav|bmp|rtf|js|eot|woff|svg|htc)$ {
add_header Pragma "public";
add_header Cache-Control "public";
expires 1y;
access_log off;
log_not_found off;
}
location / {
# Check if a file exists, or route it to index.php.
try_files $uri $uri/ /index.php?$query_string;
}
location ~\.php$ {
try_files $uri =404;
fastcgi_pass unix:/dev/shm/apache-php.sock;
fastcgi_index index.php;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
include /etc/nginx/fastcgi_params;
}
location #backend {
rewrite ^(.*)$ /images.php?url=$1;
}