:term:`PSGI` is the equivalent of :term:`WSGI` in the Perl world.

• http://plackperl.org/
• http://github.com/miyagawa/psgi-specs/blob/master/PSGI.pod

The PSGI plugin is officially supported and has an officially assigned uwsgi modifier, 5. So as usual, when you're in the business of dispatching requests to Perl apps, set the modifier1 value to 1 in your web server configuration.

You can build a PSGI-only uWSGI server using the supplied :file:`buildconf/psgi.ini` file.

python uwsgiconfig --build psgi
# or compile it as a plugin...
python uwsgiconfig --plugin plugins/psgi
# and if you have not used the default configuration
# to build the uWSGI core, you have to pass
# the configuration name you used while doing that:
python uwsgiconfig --plugin plugins/psgi core

There is only one option exported by the plugin: psgi <app>

You can simply load applications using

./uwsgi -s :3031 -M -p 4 --psgi myapp.psgi -m
# or when compiled as a plugin,
./uwsgi --plugins psgi -s :3031 -M -p 4 --psgi myapp.psgi -m

The following frameworks/apps have been tested with uWSGI:

• MojoMojo
• Mojolicious
• Mojolicious+perlbrew+uWSGI+nginx install bundle

You can load multiple almost-isolated apps in the same uWSGI process using the mount option or using the UWSGI_SCRIPT/UWSGI_FILE request variables.

[uwsgi]

mount = app1=foo1.pl
mount = app2=foo2.psgi
mount = app3=foo3.pl

server {
  server_name example1.com;
  location / {
    include uwsgi_params;
    uwsgi_pass 127.0.0.1:3031;
    uwsgi_param UWSGI_APPID app1;
    uwsgi_param UWSGI_SCRIPT foo1.pl;
    uwsgi_modifier1 5;
  }
}

server {
  server_name example2.com;
  location / {
    include uwsgi_params;
    uwsgi_pass 127.0.0.1:3031;
    uwsgi_param UWSGI_APPID app2;
    uwsgi_param UWSGI_SCRIPT foo2.psgi;
    uwsgi_modifier1 5;
  }
}

server {
  server_name example3.com;
  location / {
    include uwsgi_params;
    uwsgi_pass 127.0.0.1:3031;
    uwsgi_param UWSGI_APPID app3;
    uwsgi_param UWSGI_SCRIPT foo3.pl;
    uwsgi_modifier1 5;
  }
}

• Async support should work out-of-the-box.
• Threads are supported on ithreads-enabled perl builds. For each app, a new interpreter will be created for each thread. This shouldn't be too different from a simple multi-process fork()-based subsystem.
• There are currently no known memory leaks.

1. Install the HTML::Mason PSGI handler from CPAN and create a directory for your site.

   cpan install HTML::Mason::PSGIHandler
   mkdir mason

2. Create mason/index.html:

   % my $noun = 'World';
   % my $ua = $r->headers_in;
   % foreach my $hh (keys %{$ua}) {
    <% $hh %><br/>
   % }
   Hello <% $noun %>!<br/>
   How are ya?<br/>
   Request <% $r->method %> <% $r->uri %><br/>

3. Create the PSGI file (mason.psgi):

   use HTML::Mason::PSGIHandler;
   
   my $h = HTML::Mason::PSGIHandler->new(
          comp_root => "/Users/serena/uwsgi/mason", # required
   );
   
   my $handler = sub {
          my $env = shift;
          $h->handle_psgi($env);
   };

   Pay attention to comp_root, it must be an absolute path!

4. Now run uWSGI:

   ./uwsgi -s :3031 -M -p 8 --psgi mason.psgi -m

5. Then go to /index.html with your browser.