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Mojolicious::Guides::Cookbook.3pm

NAME

Mojolicious::Guides::Cookbook - Cookbook

OVERVIEW

Cooking with Mojolicious, recipes for every taste.

DEPLOYMENT

Getting Mojolicious and Mojolicious::Lite applications running on different platforms.

Builtin Server

Mojolicious contains a very portable HTTP 1.1 compliant web server. It is usally used during development but is solid and fast enough for small to mid sized applications.

     % ./script/myapp daemon
     Server available at http://127.0.0.1:3000.
 
 

It has many configuration options and is known to work on every platform Perl works on.

     % ./script/myapp help daemon
     ...List of available options...
 
 

Another huge advantage is that it supports TLS and WebSockets out of the box.

     % ./script/myapp daemon --listen https://*:3000
     Server available at https://*:3000.
 
 

A development certificate for testing purposes is built right in, so it just works.

Builtin Preforking Server

To allow scaling with multiple CPUs (cores) and to lower the performance loss from (slow) blocking APIs the built in web server also has a preforking multi process mode. It doesn't work on Windows due to UNIX optimizations but is fast and scalable enough for large applications.

     % ./script/myapp daemon_prefork
     Server available at http://127.0.0.1:3000.
 
 

By default it will accept one client connection per worker process just like Apache, but this value can be increased, allowing huge amounts of concurrent client connections. (epoll and kqueue will be used automatically if available)

     % ./script/myapp daemon_prefork --clients 100
     Server available at http://127.0.0.1:3000.
 
 

Nginx

One of the most popular setups these days is the builtin preforking web server behind a Nginx reverse proxy.

     upstream myapp {
         server 127.0.0.1:3000;
     }
     server {
         listen 80;
         server_name localhost;
         location / {
             proxy_read_timeout 300;
             proxy_pass http://myapp;
         }
     }
 
 

Also possible using UNIX domain sockets.

     upstream myapp {
         server unix:/tmp/myapp.sock;
     }
     server {
         listen 80;
         server_name localhost;
         location / {
             proxy_read_timeout 300;
             proxy_pass http://myapp;
         }
     }
 
 

The builtin web server of course supports them as well.

     % ./script/myapp daemon_prefork --listen file:///tmp/myapp.sock
     Server available at file:///tmp/myapp.sock.
 
 

One interesting side effect here is that you can start multiple prefork web servers parallel letting them share the same UNIX domain socket and lock file. This allows something called "Hot Deployment", which essentially means zero downtime software updates.

     % ./script/myapp daemon_prefork --listen file:///tmp/myapp.sock\
       --pid /tmp/myapp1.pid --lock /tmp/myapp.lock --daemonize
     Server available at file:///tmp/myapp.sock.
 
 

All you have to do is update your application code, start a second web server instance and after that send a "USR1" signal to the old instance. This will bring down the old web server gracefully, so no active connections get interrupted and your users won't notice a thing.

     % ./script/myapp daemon_prefork --listen file:///tmp/myapp.sock\
       --pid /tmp/myapp2.pid --lock /tmp/myapp.lock --daemonize
 
     % kill -s USR1 `cat /tmp/myapp1.pid`
 
 

Apache/CGI

"CGI" is supported out of the box and your Mojolicious application will automatically detect that it is executed as a "CGI" script.

     <VirtualHost *:80>
         ServerName localhost
         DocumentRoot /home/sri/myapp/public
 
         ScriptAlias /myapp "/home/sri/myapp/script/myapp"
     </VirtualHost>
 
 

Apache/FastCGI

"FastCGI" is also supported out of the box and your Mojolicious application will automatically detect that it is executed as a "FastCGI" script.

     <VirtualHost *:80>
         ServerName localhost
         DocumentRoot /home/sri/myapp/public
 
         FastCgiServer /home/sri/myapp/script/myapp -processes 10
         Alias /myapp /home/sri/myapp/script/myapp
     </VirtualHost>
 
 

PSGI/Plack

PSGI is an interface between Perl web frameworks and web servers, and Plack is a Perl module and toolkit that contains PSGI middleware, helpers and adapters to web servers. PSGI and Plack are inspired by Python's WSGI and Ruby's Rack. Mojolicious applications are ridiculously simple to deploy with Plack.

     % plackup ./script/myapp
     HTTP::Server::PSGI: Accepting connections at http://0:5000/
 
 

Plack provides many server and protocol adapters for you to choose from such as "FCGI", "SCGI" and "mod_perl". Make sure to run "plackup" from your applications home directory, otherwise libraries might not be found.

     % plackup ./script/myapp -s FCGI -l /tmp/myapp.sock
 
 

Because "plackup" uses a weird trick to load your script, Mojolicious is not always able to detect the applications home directory, if thats the case you can simply use the "MOJO_HOME" environment variable. Also note that "app->start" needs to be the last Perl statement in the application script for the same reason.

     % MOJO_HOME=/home/sri/myapp plackup ./script/myapp
     HTTP::Server::PSGI: Accepting connections at http://0:5000/
 
 

Some server adapters might ask for a ".psgi" file, if thats the case you can just point them at your application script because it will automatically act like one if it detects the presence of a "PLACK_ENV" environment variable.

Apache/mod_perl (PSGI/Plack)

"mod_perl" is a good example for a PSGI adapter that is used without "plackup", note that setting the "PLACK_ENV" environment variable is required for Mojolicious PSGI detection.

     <VirtualHost *:80>
         ServerName localhost
         DocumentRoot /home/sri/myapp/public
 
         <Perl>
             $ENV{PLACK_ENV} = 'production';
             $ENV{MOJO_HOME} = '/home/sri/myapp';
         </Perl>
 
         <Location /myapp>
             SetHandler perl-script
             PerlHandler Plack::Handler::Apache2
             PerlSetVar psgi_app /home/sri/myapp/script/myapp
         </Location>
     </VirtualHost>
 
 

IIS6.0/FastCGI

We don't suggest using IIS, it is a horribly broken web server, avoid it if you can. There is nothing we can do to make this a pleasant experience for you, but maybe we can at least ease some of the pain.

First you should make sure to get recent versions of "Strawberry Perl" and Mojolicious installed, "Strawberry" is as good as a Windows version of Perl can be.

Then you'll have to install IIS 6.0 and its FastCGI extension, which is not part of the standard installation. Create a new website with "Control Panel" > "Administrative Tools" > "Internet Information Services Manager" > "Action" > "New" > "Web Site" and finish the installation wizard.

Open your newly created websites properties and select the tab "Web Site". Set the proper values for "Site Description", "IP Address", "TCP Port", "SSL Port" etc.

On the tab "Home Directory" set "Local Path" to "c:\myapp\public", "Local Path Permission Flags" to "Read" and "Log Visits", "Execute Permissions" to "Scripts Only".

Click on the "Configuration" button and then "Insert" (next to "Wildcard Application Mappings"). In the next dialog set "Executable" to "c:\windows\system32\inetsrv\fcgiext.dll" and uncheck "Verify That Files Exist".

Now put the following lines into "c:\windows\system32\inetsrv\fcgiext.ini" or "c:\windows\syswow64\inetsrv\fcgiext.ini" on 64-bit systems.

     [Types]
     *=MyApp
 
     [MyApp]
     ExePath=c:\strawberry\perl\bin\perl.exe
     Arguments="c:\myapp\script\myapp fastcgi"
 
     ; Let IIS serve static files
     IgnoreExistingFiles=0
     IgnoreDirectories=1
 
 

There is one more thing, IIS sometimes clears your environment variables but Windows won't work without "SYSTEMROOT", so you might have to set it manually in your application.

     # Application
     package MyApp;
     use base 'Mojolicious';
 
     sub startup {
         my $self = shift;
 
         # Use plugin hook to set environment variable for every request
         $self->plugins->add_hook(
             before_dispatch => sub { $ENV{SYSTEMROOT} = 'c:\\winnt' }
         );
     }
 
     1;
 
 

FUN

Hacks that might not be very useful but are fun! :)

Hello World

If every byte matters this is the smallest "Hello World" application you can write with Mojolicious::Lite.

     use Mojolicious::Lite;
     get '/' => {text => 'Hello World!'};
     app->start;
 
 

It works because automatic rendering kicks in even if no actual code gets executed by the router, the renderer just picks up the "text" value from the stash and generates a response.