Conditionally prepend path to url in NGINX - nginx

Question

I have this directory structure for my projects
/var/www
/project-a
/data <-- configuration and user files/data
/app <-- all the code is in sub-dirs in here
/pm <-- a home brew project management app
/.pmdata <-- data used by pm
My goal is to configure NGINX so I can access the project itself through
http://project-a.dev/ and the project management with http://project-a.dev/pm/.
In other words, I want the second url preserved as is, but if the url does not point to /pm/* it should be re-written to have the missing /app prepended to it.
I have tried the following configuration but http://project-a.dev/pm/ results in 404 and http://project-a.dev/ first redirects to http://project-a.dev/app/ and then gives 404.
What am I doing wrong?
server {
listen 127.0.0.1:80;
root /var/www/project-a;
index index.php index.html index.htm;
server_name project-a.dev;
location / {
try_files $uri $uri/app $uri/app/ =404;
}
location ~ \.php$ {
try_files $uri =404;
fastcgi_split_path_info ^(.+\.php)(/.+)$;
fastcgi_pass unix:/var/run/php5-fpm.sock;
fastcgi_index index.php;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
include fastcgi_params;
}
}

Answer 1

Alternatively you could append /app to the root value for all URIs that do not begin with /pm. For example:
server {
...
root /var/www/project-a/app;
index index.php index.html index.htm;
location / {
try_files $uri $uri/ =404;
}
location ~ \.php$ {
try_files $uri =404;
fastcgi_pass unix:/var/run/php5-fpm.sock;
include fastcgi_params;
fastcgi_param SCRIPT_FILENAME $request_filename;
}
location ^~ /pm {
root /var/www/project-a;
try_files $uri $uri/ =404;
location ~ \.php$ {
try_files $uri =404;
fastcgi_pass unix:/var/run/php5-fpm.sock;
include fastcgi_params;
fastcgi_param SCRIPT_FILENAME $request_filename;
}
}
}
The nested location block for location ~ \.php$ executes PHP files within the /pm hierarchy. The ^~ modifier is necessary to avoid the other location ~ \.php$ block taking control. See this document for details.