Allow index a folder, but don't serve files - nginx

Question

I want to allow Nginx to autoindex a folder, but not serve the files.
In my app, the files are stocked in a protected-files folder and this folder isn't accessible for users. When a user calls a file (eg: my-website.com/files/my-great-files.pdf), in reality, he was redirected on a PHP script that verify if the user have the rights to call this file. I know how to do that, and it's ok.
But actually, I want use a JS plugin named jBrowse, and this program need to access to a lot of files, and to the index of a folder to have the files list in it.
And I don't know how to do this... Can we return a file index in PHP ?
Or an other idea, permit to Nginx to return the index of a folder with empty files. And when a user or the plugin want access to the file, he's redirect on the PHP script that control the rights.
I've mind this:
location /files {
autoindexon;
}
location ~* \.(doc|pdf)$ {
deny all;
}
This is ok, the user can navigate in the folder, see the files, but if he click on, he has an 403 error. But I can't replace the deny all, by a redirection to php...
This is my default.conf file:
server {
server_name project.dev;
root /home/docker/web;
location / {
# try to serve file directly, fallback to app.php
#try_files $uri /app.php$is_args$args;
try_files $uri /app_dev.php$is_args$args;
}
location /protected_files {
internal;
alias /home/docker/protected-files;
}
location /files {
autoindex on;
}
location ~* \.(doc|pdf)$ {
try_files $uri /app_dev.php$is_args$args;
}
# DEV
# This rule should only be placed on your development environment
# In production, don't include this and don't deploy app_dev.php or config.php
location ~ ^/(app_dev|config)\.php(/|$) {
fastcgi_pass engine:9000;
fastcgi_split_path_info ^(.+\.php)(/.*)$;
include fastcgi_params;
# When you are using symlinks to link the document root to the
# current version of your application, you should pass the real
# application path instead of the path to the symlink to PHP
# FPM.
# Otherwise, PHP's OPcache may not properly detect changes to
# your PHP files (see https://github.com/zendtech/ZendOptimizerPlus/issues/126
# for more information).
fastcgi_param SCRIPT_FILENAME $realpath_root$fastcgi_script_name;
fastcgi_param DOCUMENT_ROOT $realpath_root;
}
# PROD
location ~ ^/app\.php(/|$) {
fastcgi_pass engine:9000;
fastcgi_split_path_info ^(.+\.php)(/.*)$;
include fastcgi_params;
# When you are using symlinks to link the document root to the
# current version of your application, you should pass the real
# application path instead of the path to the symlink to PHP
# FPM.
# Otherwise, PHP's OPcache may not properly detect changes to
# your PHP files (see https://github.com/zendtech/ZendOptimizerPlus/issues/126
# for more information).
fastcgi_param SCRIPT_FILENAME $realpath_root$fastcgi_script_name;
fastcgi_param DOCUMENT_ROOT $realpath_root;
# Prevents URIs that include the front controller. This will 404:
# http://domain.tld/app.php/some-path
# Remove the internal directive to allow URIs like this
#internal;
}
error_log /var/log/nginx/project_error.log;
access_log /var/log/nginx/project_access.log;
}

Answer 1

You can replace the deny all with a rewrite directive to perform an internal redirect to your php handler.
location /files {
autoindex on;
}
location ~* ^/files.*\.(doc|pdf)$ {
rewrite ^ /app_dev.php last;
}
See this document for details.
EDIT: You may want to make your regex more specific so that only URIs beginning with /files and ending with .doc or .pdf match. Either change the regex (as above) or nest it within the location /files block, as follows:
location /files {
autoindex on;
location ~* \.(doc|pdf)$ {
rewrite ^ /app_dev.php last;
}
}