1.
Plack Basics
Leo Lapworth @ YAPC::EU 2011
Much content from Tatsuhiko Miyagawa’s
YAPC::NA 2010 talk

2.
What is Plack?

3.
What is Plack?
“Superglue for Perl 5 Web
Frameworks and Web
Servers”

4.
How will that help me?

5.
How will that help me?
‣ Flexibility

6.
How will that help me?
‣ Flexibility
‣ Middleware (plugins)

7.
How will that help me?
‣ Flexibility
‣ Middleware (plugins)
‣ Apps

8.
How will that help me?
‣ Flexibility
‣ Middleware (plugins)
‣ Apps
‣ Development

9.
How will that help me?
‣ Flexibility
‣ Middleware (plugins)
‣ Apps
‣ Development
‣ Testing

10.
How will that help me?
‣ Flexibility
‣ Middleware (plugins)
‣ Apps
‣ Development
‣ Testing
‣ Deployment

11.
How will that help me?
‣ Flexibility
‣ Middleware (plugins)
‣ Apps
‣ Development
‣ Testing
‣ Deployment
‣ World peace

12.
How will that help me?
‣ Flexibility
‣ Middleware (plugins)
‣ Apps
‣ Development
‣ Testing
‣ Deployment
‣ World peace

13.
History...

14.
Hello World

15.
#!/usr/bin/perl
use strict;
print “Content-Type: text/plainrnrn”;
print “Hello World”;

16.
package HelloWorld;
use strict;
use Apache::RequestRec;
use Apache::RequestIO;
use Apache::Const -compile => qw(OK);
sub handler {
my $r = shift;
$r->content_type(‘text/plain’);
$r->print(“Hello World”);
return Apache::Const::OK;
}
1;

17.
use FCGI;
my $req = FCGI::Request();
while ($req->Accept >= 0) {
print “Content-Type: text/plainrnrn”;
print “Hello World”;
}

18.
package HelloWorld;
use base qw(HTTP::Server::Simple::CGI);
sub handle_request {
my($self, $cgi) = @_;
print “HTTP/1.0 200 OKrn”;
print “Content-Type: text/plainrnrn”;
print “Hello World”;
}
1;

19.
All similar
but slightly different

20.
Painful to support
all of them 

21.
There was
one common way
to do all of this.

22.
CGI.pm

23.
#!/usr/bin/perl
use CGI;
my $q = CGI->new;
print $q->header(‘text/plain’);
print “Hello World”;

24.
Works under...
CGI
FastCGI
mod_perl
HTTP::Server::Simple::CGI

25.
CGI.pm
mod_perl CGI fastcgi
Apache IIS lighttpd

26.
CGI.pm?

27.
CGI.pm?
meh

28.
Frameworks
to the rescue!

29.
Catalyst Maypole Mason Mojo Sledge Spoon
PageKit AxKit Egg Gantry Continuity Solstice
Mojolicious Tripletail Konstrukt Reaction Jifty
Cyclone3 WebGUI OpenInteract Squatting
Dancer CGI::Application Nanoa Ark Angelos
Noe Schenker Tatsumaki Amon
Apache2::WebApp Web::Simple Apache2::REST
SweetPea Hydrant Titanium

30.
Let’s look how they
handled web servers.

31.
CGI.pm
mod_perl CGI fastcgi
Apache IIS lighttpd

32.
CGI::Application
Apache IIS lighttpd

33.
CGI::Application
CGI.pm
Apache IIS lighttpd

34.
CGI::Application
CGI.pm
mod_perl CGI fastcgi
Apache IIS lighttpd

35.
CGI::Application Jifty
CGI.pm
mod_perl CGI fastcgi
Apache IIS lighttpd

36.
CGI::Application Jifty Catalyst
CGI.pm
mod_perl CGI fastcgi
Apache IIS lighttpd

37.
CGI::Application Jifty Catalyst
CGI.pm Catalyst::Engine
mod_perl CGI fastcgi
Apache IIS lighttpd

38.
CGI::Application Jifty Catalyst
CGI.pm Catalyst::Engine
mod_perl CGI fastcgi
Apache IIS lighttpd nginx

39.
CGI::Application Jifty Catalyst
CGI.pm Catalyst::Engine
mod_perl CGI fastcgi
HTTP::Server
::Simple Apache IIS lighttpd nginx

40.
Mason CGI::Application Jifty Catalyst
CGI.pm Catalyst::Engine
mod_perl CGI fastcgi
HTTP::Server
::Simple Apache IIS lighttpd nginx

41.
Mason CGI::Application Jifty Catalyst
Mason::CGIHandler
CGI.pm Catalyst::Engine
mod_perl CGI fastcgi
HTTP::Server
::Simple Apache IIS lighttpd nginx

42.
Gross.

43.
CGI.pm
Jifty, CGI::Application, Spoon
mod_perl centric
Mason, Sledge, PageKit, WebGUI
Adapters
Catalyst, Maypole, Squatting

44.
That was 2008...

45.
Gentleman thief &
Double agent
Miyagawa

46.
Acquired a great idea
from Python/Ruby

47.
WSGI (Python)
Rack (Ruby)

48.
WSGI (PEP-333)

49.
WSGI Python Frameworks
• Django • mod_wsgi
• Bottle • Paste
• CherryPy • gunicorn
• Tornado • uWSGI
• Pylons • wsgiref
• Flask • Google AppEngine

50.
Django Bottle Flask Tornado
WSGI middleware
WSGI
wsgi handlers
Apache lighttpd nginx mod_wsgi GAE

51.
Rack

52.
Rack Ruby Frameworks
• Rails • Unicorn
• Merb • Thin
• Sinatra • Mongrel
• Camping • Rainbows!
• Ramaze • Phusion Passenger
• etc. • Heroku

53.
Rails Merb Sinatra Ramaze
Rack middleware
Rack
Rack handlers
Apache lighttpd Thin Unicorn Mongrel

54.
Perl ?

55.
PSGI Perl ?
Perl Web Server Gateway Interface

56.
Interface

57.
Interface

58.
Interface
PSGI != Plack

59.
PSGI application
code reference
$app = sub {...};

60.
# PSGI Hello World
my $app = sub {
my $env = shift;
return [
200,
[ ‘Content-Type’, ‘text/plain’ ],
[ ‘Hello World’ ],
];
};

61.
my $app = sub {
my $env = shift;
return [ $status, $header, $body ];
};
CGI-like environment variables
+ psgi.input, psgi.errors etc.

62.
my $app = sub {
my $env = shift;
return [ $status, $header, $body ];
};
HTTP status code (int.): 200, 404 etc.

63.
my $app = sub {
my $env = shift;
return [ $status, $header, $body ];
};
Array reference of header pairs:
[ ‘Content-Type’, ‘text/html’, ... ]

64.
my $app = sub {
my $env = shift;
return [ $status, $header, $body ];
};
String, array reference of content chunks,
Filehandle or IO::Handle-ish object

65.
That’s it.
(There’s a callback based streaming interface as well)

66.
# PSGI
my $app = sub {
my $env = shift;
return [
200,
[ ‘Content-Type’, ‘text/plain’ ],
[ ‘Hello World’ ],
];
};

67.
Now you’ve got
a PSGI compatible
application.

68.
Mason CGI::App Jifty Catalyst
Mason::CGIHandler
CGI.pm Catalyst::Engine
mod_perl CGI fastcgi
HTTP::Server
::Simple Apache IIS lighttpd nginx

69.
Catalyst CGI::App Jifty Mason 2
Plack::Middleware
PSGI Compatible App
Plack::Handler::* (CGI, FCGI, Apache)
Apache lighttpd HTTP::Server::PSGI mod_psgi Perlbal

70.
Catalyst CGI::App Jifty Mason 2
Plack::Middleware
PSGI Compatible App
Plack::Handler::* (CGI, FCGI, Apache)
Apache lighttpd HTTP::Server::PSGI mod_psgi Perlbal
other PSGI Webservers

71.
Web Servers

72.
Plack::Handler
Connects PSGI compatible apps
to Web servers...

73.
FCGI
Plack::Handler::FCGI

74.
Apache
Plack::Handler::Apache1
Plack::Handler::Apache2

75.
Starman
UNIX Preforking HTTP servers (like Unicorn.rb)
HTTP/1.1 chunk + keep-alives / Very Fast

76.
HTTP::Server::Simple::PSGI
Zero-deps other than HTTP::Server::Simple
Best for embedding PSGI applications

77.
Twiggy
Non-blocking web server (like Thin.rb)
based on AnyEvent framework
Starlet
Simpler UNIX HTTP/1.0 Server
Best used with Server::Starter and nginx/lighttpd

78.
Perlbal plugin
http://github.com/miyagawa/Perlbal-Plugin-PSGI

79.
nginx embedded perl
http://github.com/yappo/nginx-psgi-patchs

80.
mod_psgi
http://github.com/spiritloose/mod_psgi
Apache2

81.
Corona uWSGI
Coroutine for each connection http://projects.unbit.it/uwsgi/
based on Coro.pm
Feersum evpsgi
http://github.com/stash/Feersum http://github.com/sekimura/evpsgi
Gepok
http://metacpan/module/Gepok
Pure Perl standalone HTTPS
First released July 2011

82.
Frameworks Apps Your own code
Plack::Middleware
PSGI
Plack::Handler::* (CGI, FCGI, Apache)

83.
Frameworks Apps Your own code
Plack::Middleware
PSGI
Plack::Handler::* (CGI, FCGI, Apache)
Apache lighttpd HTTP::Server::PSGI mod_psgi Perlbal
Starman Twiggy uWSGI Corona etc, etc

84.
25+ Plack::Handlers

85.
Adoption?

86.
Plack::Middleware
PSGI Compatible App
Plack::Handler::* (CGI, FCGI, Apache)
Apache lighttpd HTTP::Server::PSGI mod_psgi Perlbal
Starman Twiggy uWSGI Corona etc

87.
?
Plack::Middleware
PSGI Compatible App
Plack::Handler::* (CGI, FCGI, Apache)
Apache lighttpd HTTP::Server::PSGI mod_psgi Perlbal
Starman Twiggy uWSGI Corona etc

88.
Catalyst Maypole Mason Mojo Sledge Spoon PageKit
AxKit Egg Gantry Continuity Solstice Mojolicious
Tripletail Konstrukt Reaction Jifty Cyclone3 WebGUI
OpenInteract Squatting Dancer CGI::Application
Nanoa Ark Angelos Noe Schenker Tatsumaki Amon
Apache2::WebApp Web::Simple Apache2::REST
SweetPea Hydrant Titanium

89.
Catalyst Maypole Mason Mojo Sledge Spoon PageKit
AxKit Egg Gantry Continuity Solstice Mojolicious
Tripletail Konstrukt Reaction Jifty Cyclone3 WebGUI
OpenInteract Squatting Dancer CGI::Application
Nanoa Ark Angelos Noe Schenker Tatsumaki Amon
Apache2::WebApp Web::Simple Apache2::REST
SweetPea Hydrant Titanium

90.
PSGI Perl Frameworks
• Amon • Hydrant • Schenker
• Angelos • Jifty • Sledge
• Ark • Mason • Squatting
• Catalyst • Maypole • Tatsumaki
• CGI::Application • Mojo • Titanium
• Continuity • Mojolicious • Web::Simple
• Dancer • Noe

91.
Applications
Movable Type 6
WebGUI 8
RT4
ACT (conference toolkit)
Bricolage (if someone gets time)

92.
Plack::Middleware
PSGI Compatible App
Plack::Handler::* (CGI, FCGI, Apache)
Apache lighttpd HTTP::Server::PSGI mod_psgi Perlbal
Starman Twiggy uWSGI Corona evpsgi

93.
Catalyst CGI::App Jifty Tatsumaki
Dancer Mojoliscious MT6 Mason 2
Web::Simple WebGui 8 Mojo etc...
Plack::Middleware
PSGI Compatible App
Plack::Handler::* (CGI, FCGI, Apache)
Apache lighttpd HTTP::Server::PSGI mod_psgi Perlbal
Starman Twiggy uWSGI Corona evpsgi

94.
PSGI from a framework

95.
use Dancer;
get ‘/’ => sub {
“Hello World”;
};
dance;

96.
use Mojolicious::Lite;
get ‘/:name’ => sub {
my $self = shift;
$self->render_text(‘Hello!’);
};
app->start;

97.
use My::Jifty::App;
my $app = My::Jifty::App->psgi_app;

98.
use Web::Simple ‘MyApp’;
package MyApp;
dispatch {
sub(GET) {
[ 200, [...], [ ‘Hello’ ] ];
}
};
my $app = MyApp->as_psgi;

99.
use My::Catalyst::App;
My::Catalyst::App->setup_engine(‘PSGI’);
my $app = sub {
My::Catalyst::App->run(@_)
};

100.
catalyst.pl My::Catalyst::App

101.
Plack
“PSGI implementation & toolkit”

102.
Plack toolkit

103.
Plack toolkit
Plack::Handlers Connect PSGI apps and Web Servers

104.
Plack toolkit
Plack::Handlers Connect PSGI apps and Web Servers
plackup Command line launcher

105.
Plack toolkit
Plack::Handlers Connect PSGI apps and Web Servers
plackup Command line launcher
Plack::Loader (auto)load Plack Servers

106.
Plack toolkit
Plack::Handlers Connect PSGI apps and Web Servers
plackup Command line launcher
Plack::Loader (auto)load Plack Servers
Plack::Middleware Easy-to-use PSGI Middleware

107.
Plack toolkit
Plack::Handlers Connect PSGI apps and Web Servers
plackup Command line launcher
Plack::Loader (auto)load Plack Servers
Plack::Middleware Easy-to-use PSGI Middleware
Plack::Builder OO & DSL to enable Middleware

108.
Plack toolkit
Plack::Handlers Connect PSGI apps and Web Servers
plackup Command line launcher
Plack::Loader (auto)load Plack Servers
Plack::Middleware Easy-to-use PSGI Middleware
Plack::Builder OO & DSL to enable Middleware
Plack::Apps Apps

109.
Plack toolkit
Plack::Handlers Connect PSGI apps and Web Servers
plackup Command line launcher
Plack::Loader (auto)load Plack Servers
Plack::Middleware Easy-to-use PSGI Middleware
Plack::Builder OO & DSL to enable Middleware
Plack::Apps Apps
Plack::Test Testing

110.
plackup
Runs PSGI app instantly from CLI
(inspired by rackup)

111.
> plackup app.psgi

112.
> plackup app.psgi
HTTP::Server::PSGI: Accepting
connections at http://0:5000/

113.
HTTP::Server::PSGI
Reference PSGI web server
bundled in Plack
Standalone, single-process HTTP server
great for development and testing

114.
Plack::Middleware
(160+ modules - July 2011)

115.
Middleware
Debug, Session, Logger, Static, Lint,
AccessLog, ErrorDocument, StackTrace, Auth::Basic,
Auth::Digest, ReverseProxy, Refresh, Auth::OAuth,
Throttle....

116.
Chunked Class::Refresh Compile Conditional ConditionalGET
ConsoleLogger ContentLength ContentMD5 CrossOrigin
CSRFBlock Dancer::Debug DBIC::QueryLog Debug
Debug::CatalystPluginCache Debug::DBIC::QueryLog
Debug::DBIProfile Debug::Profiler::NYTProf Debug::W3CValidate
Deflater DoCoMoGUID Doorman ErrorDocument ESI ETag
Expires File::Sass Firebug::Lite FirePHP ForceEnv Head Header
HTMLify HTMLMinify HTTPExceptions IEnosniff IIS6ScriptNameFix
Image::Scale Inline InteractiveDebugger IPAddressFilter iPhone
JavaScript::Ectype JSConcat JSONP LighttpdScriptNameFix Lint
Log::Contextual Log::Minimal Log4perl LogDispatch LogWarn
MethodOverride Mirror NeverExpire NoDeflate NoMultipleSlashes
NullLogger Options OptionsOK Precompressed ProxyMap
RearrangeHeaders Recursive RefererCheck Refresh REPL Reproxy
ReverseProxy Rewrite Runtime Scope::Container Scope::Session
ServerStatus::Lite Session Session::SerializedCookie SetAccept
SimpleContentFilter SimpleLogger SizeLimit SocketIO SSI
StackTrace Static Static::Minifier StaticShared Status
Test::StashWarnings Throttle TMT UseChromeFrame Watermark

117.
Plack Middleware
Wraps a PSGI application
to add pre/post processing

118.
Logging

119.
Logging
Status code redirect

120.
Logging
Status code redirect
Error Handler

121.
Logging
Status code redirect
Error Handler
Cache Middleware

122.
Logging
Status code redirect
Error Handler
Cache Middleware
Session Middleware

123.
Logging
Status code redirect
Error Handler
Cache Middleware
Session Middleware
Routes Middleware

124.
Logging
Status code redirect
Error Handler
Cache Middleware
Session Middleware
Routes Middleware
Your App

125.
Plack::Middleware::A
Plack::Middleware::B
PSGI Compatible App

126.
Plack::Middleware::A
Plack::Middleware::B
PSGI Compatible App
Request in

127.
Plack::Middleware::A
Plack::Middleware::B
PSGI Compatible App
Request in
P::MW::A

128.
Plack::Middleware::A
Plack::Middleware::B
PSGI Compatible App
Request in
P::MW::A
P::MW::B

129.
Plack::Middleware::A
Plack::Middleware::B
PSGI Compatible App
Request in
P::MW::A
P::MW::B
PSGI App

130.
Plack::Middleware::A
Plack::Middleware::B
PSGI Compatible App
Request in
P::MW::A
P::MW::B P::MW::B
PSGI App

131.
Plack::Middleware::A
Plack::Middleware::B
PSGI Compatible App
Request in
P::MW::A P::MW::A
P::MW::B P::MW::B
PSGI App

132.
Plack::Middleware::A
Plack::Middleware::B
PSGI Compatible App
Request in Response out
P::MW::A P::MW::A
P::MW::B P::MW::B
PSGI App

133.
Plack::Middleware::A
Plack::Middleware::B
PSGI Compatible App
Request in e.g. Redirect Response out
P::MW::A P::MW::A
P::MW::B P::MW::B
PSGI App

134.
Plack::Middleware::A
Plack::Middleware::B
PSGI Compatible App
Request in e.g. Redirect Response out
P::MW::A P::MW::A
e.g. Static
P::MW::B P::MW::B
PSGI App

135.
Enabling
Plack::Middleware
reusable and extensible
Middleware framework
Plack::Builder DSL in .psgi

136.
my $app = sub {
return [ $status, $header, $body ];
};
use Plack::Builder;
return builder {
enable “A”;
enable “B”;
$app;
}

137.
my $app = sub {
return [ $status, $header, $body ];
};
use Plack::Builder;
return builder {
enable “A”;
enable “B”;
$app;
}

138.
my $app = sub {
return [ $status, $header, $body ];
};
use Plack::Builder;
return builder {
enable “A”;
enable “B”;
$app;
}

139.
my $app = sub {
return [ $status, $header, $body ];
};
use Plack::Builder;
return builder {
enable “A”;
enable “B”;
$app;
}

140.
my $app = sub {
return [ $status, $header, $body ];
};
use Plack::Builder;
return builder {
enable “A”; # Plack::Middleware::A
enable “B”; # Order matters
$app;
}

141.
my $app = sub {
return [ $status, $header, $body ];
};
use Plack::Builder;
return builder {
enable “A”;
enable “B”;
$app;
}

142.
my $app = sub {
return [ $status, $header, $body ];
};
use Plack::Builder;
return builder {
enable “Static”, root => “/htdocs”,
path => qr!^/static/!;
enable “Deflater”;
$app;
}

143.
my $app = sub {
return [ $status, $header, $body ];
};
use Plack::Builder;
return builder {
enable “Static”, root => “/htdocs”,
path => qr!^/static/!;
enable “Deflater”;
$app;
}

144.
my $app = sub {
return [ $status, $header, $body ];
};
use Plack::Builder;
return builder {
enable “Static”, root => “/htdocs”,
path => qr!^/static/!;
enable “Deflater”; # gzip/deflate
$app;
}

145.
my $app = sub {
return [ $status, $header, $body ];
};
use Plack::Builder;
return builder {
enable “Static”, root => “/htdocs”,
path => qr!^/static/!;
enable “Deflater”;
$app;
}

146.
Plack::Middleware::Static
Plack::Middleware::Deflate
PSGI Compatible App

147.
Plack::Middleware::Static
Plack::Middleware::Deflate
PSGI Compatible App
Request in

148.
Plack::Middleware::Static
Plack::Middleware::Deflate
PSGI Compatible App
Request in
Static

149.
Plack::Middleware::Static
Plack::Middleware::Deflate
PSGI Compatible App
Request in Response out
=~ ^/static
Static

150.
Plack::Middleware::Static
Plack::Middleware::Deflate
PSGI Compatible App
Request in Response out
=~ ^/static
Static
-

151.
Plack::Middleware::Static
Plack::Middleware::Deflate
PSGI Compatible App
Request in Response out
=~ ^/static
Static
-
PSGI App

152.
Plack::Middleware::Static
Plack::Middleware::Deflate
PSGI Compatible App
Request in Response out
=~ ^/static
Static
- Deflate compresses
PSGI App

153.
Plack::Middleware::Static
Plack::Middleware::Deflate
PSGI Compatible App
Request in Response out
=~ ^/static
Static -
- Deflate compresses
PSGI App

154.
Plack::Middleware::Static
Plack::Middleware::Deflate
PSGI Compatible App
Request in Response out
=~ ^/static
Static -
- Deflate compresses
PSGI App

155.
plackup compatible
plackup -e ‘enable “Foo”;’ app.psgi

156.
Middleware
Write once, run in every framework

157.
A few demos..

158.
Assume...
use Plack::Builder;
my $body = ‘<html><body>Hello World</body></html>’;
my $app = sub {
my $self = shift;
return [200, ['Content-Type' => 'text/html'], [ $body ]];
};

159.
Assume...
use Plack::Builder;
my $body = ‘<html><body>Hello World</body></html>’;
my $app = sub {
my $self = shift;
return [200, ['Content-Type' => 'text/html'], [ $body ]];
};

160.
Assume...
use Plack::Builder;
my $body = ‘<html><body>Hello World</body></html>’;
my $app = sub {
my $self = shift;
return [200, ['Content-Type' => 'text/html'], [ $body ]];
};

161.
Debugger

162.
return builder {
# Precious debug info. Right on your page!
enable 'Debug';
$app;
}

163.
InteractiveDebugger

164.
my $app = sub {
my $foo = 'bar';
die "oops" if $foo eq 'bar';
[200, ['Content-Type' => 'text/html'], [ $body ]];
};
return builder {
# Enable Interactive debugging
enable "InteractiveDebugger";
$app;
}

165.
my $app = sub {
my $foo = 'bar';
die "oops" if $foo eq 'bar';
[200, ['Content-Type' => 'text/html'], [ $body ]];
};
return builder {
# Enable Interactive debugging
enable "InteractiveDebugger";
$app;
}

166.
my $app = sub {
my $foo = 'bar';
die "oops" if $foo eq 'bar';
[200, ['Content-Type' => 'text/html'], [ $body ]];
};
return builder {
# Enable Interactive debugging
enable "InteractiveDebugger";
$app;
}

167.
NYTProf - profiler

168.
First rule of Program
Optimisation

169.
Don’t do it!

170.
Second rule of Program
Optimisation
(for experts only)

171.
Don’t do it -
yet!

172.
return builder {
enable 'Debug', panels => [ [ 'Profiler::NYTProf' ] ];
$app;
};

173.
ServerStatus::Lite

174.
use Plack::Builder;
return builder {
enable "ServerStatus::Lite",
path => '/server-status',
allow => [ '127.0.0.1'],
scoreboard => '/tmp/score';
$app;
}

175.
SizeLimit

176.
use Plack::Builder;
return builder {
enable "SizeLimit",
max_unshared_size_in_kb => 3000,
check_every_n_requests => 5;
$app;
}

177.
Plack::App::*
ready-to-use applications

178.
Apache::ActionWrapper CGIBin Cascade
CocProxy DAV Directory Directory::Xslate
FCGIDispatcher File ImageMagick JSP PSGIBin
Path::Router Proxy
Proxy::Backend::AnyEvent::HTTP
Proxy::Backend::LWP Proxy::Selective Proxy::Test
URLMap WrapApacheReq
WrapApacheReq::FakeRequest WrapCGI

179.
Plack::App::CGIBin
mount /cgi-bin as PSGI applications

180.
CGI::PSGI
Easy migration from CGI.pm

181.
Plack::App::Directory
Static content file server

182.
Plack::App::Proxy
(non-blocking) proxy server
Can be used as reverse proxy as well

183.
Plack::App::JSP
Runs JavaScript PSGI apps :)

184.
# app.psgi - Javascript!
Plack::App::JSP->new( js => q{
function respond(body) {
return [ 200, [ 'Content-type', 'text/html' ], [ body ] ]
}
respond("Five factorial is " +
(function(x) {
if ( x<2 ) return x;
return x * arguments.callee(x - 1);
})(5)
);
});

185.
# app.psgi - Javascript!
Plack::App::JSP->new( js => q{
function respond(body) {
return [ 200, [ 'Content-type', 'text/html' ], [ body ] ]
}
respond("Five factorial is " +
(function(x) {
if ( x<2 ) return x;
return x * arguments.callee(x - 1);
})(5)
);
});

186.
Plack::App::URLMap
Multiplex multiple apps
Integrated with Builder DSL

187.
use CatApp;
use CGIApp;
my $c1 = sub { CatApp->run };
my $c2 = sub { CGIApp->run_psgi };
use Plack::Builder;
return builder {
mount “/cat” => $c1;
mount “/cgi-app” => builder {
enable “StackTrace”;
$c2;
};
}

188.
use CatApp;
use CGIApp;
my $c1 = sub { CatApp->run };
my $c2 = sub { CGIApp->run_psgi };
use Plack::Builder;
return builder {
mount “/cat” => $c1;
mount “/cgi-app” => builder {
enable “StackTrace”;
$c2;
};
}

189.
use CatApp;
use CGIApp;
my $c1 = sub { CatApp->run };
my $c2 = sub { CGIApp->run_psgi };
use Plack::Builder;
return builder {
mount “/cat” => $c1;
mount “/cgi-app” => builder {
enable “StackTrace”;
$c2;
};
}

190.
Some more demos...

191.
Basic website

192.
TemplateToolkit +
Static

193.
my $root = '/path/to/html_doc_root';
my $app = Plack::Middleware::TemplateToolkit->new(
INCLUDE_PATH => root,
)->to_app;
return builder {
enable 'Static',
path =>
qr{.[gif|png|jpg|swf|ico|mov|mp3|pdf|js|css]$},
root => $root;
$app;
}

194.
my $root = '/path/to/html_doc_root';
my $app = Plack::Middleware::TemplateToolkit->new(
INCLUDE_PATH => root,
)->to_app;
return builder {
enable 'Static',
path =>
qr{.[gif|png|jpg|swf|ico|mov|mp3|pdf|js|css]$},
root => $root;
$app;
}

195.
my $root = '/path/to/html_doc_root';
my $app = Plack::Middleware::TemplateToolkit->new(
INCLUDE_PATH => root,
)->to_app;
return builder {
enable 'Static',
path =>
qr{.[gif|png|jpg|swf|ico|mov|mp3|pdf|js|css]$},
root => $root;
$app;
}

196.
my $root = '/path/to/html_doc_root';
my $app = Plack::Middleware::TemplateToolkit->new(
INCLUDE_PATH => root,
)->to_app;
return builder {
enable 'Static',
path =>
qr{.[gif|png|jpg|swf|ico|mov|mp3|pdf|js|css]$},
root => $root;
$app;
}

197.
my $root = '/path/to/html_doc_root';
my $app = Plack::Middleware::TemplateToolkit->new(
INCLUDE_PATH => root,
)->to_app;
return builder {
enable 'Static',
path =>
qr{.[gif|png|jpg|swf|ico|mov|mp3|pdf|js|css]$},
root => $root;
$app;
}

198.
Creating utilities

199.
Caching Proxy

200.
Website

201.
Website
Developing code

202.
Website
Developing code

203.
Slow website
Website
Developing code

204.
Slow website
Developing code

205.
Slow website
Caching Proxy
Developing code

206.
use Plack::Middleware::Cache;
use Plack::App::Proxy;
my $app
= Plack::App::Proxy->new(
remote => "http://london.pm.org/" )->to_app;
return builder {
enable "Cache",
match_url => '^/.*', # everything
cache_dir => '/tmp/plack-cache';
$app;
};

207.
use Plack::Middleware::Cache;
use Plack::App::Proxy;
my $app
= Plack::App::Proxy->new(
remote => "http://london.pm.org/" )->to_app;
return builder {
enable "Cache",
match_url => '^/.*', # everything
cache_dir => '/tmp/plack-cache';
$app;
};

208.
use Plack::Middleware::Cache;
use Plack::App::Proxy;
my $app
= Plack::App::Proxy->new(
remote => "http://london.pm.org/" )->to_app;
return builder {
enable "Cache",
match_url => '^/.*', # everything
cache_dir => '/tmp/plack-cache';
$app;
};

209.
use LWP::Simple;
my $content = get(‘http://localhost:5000/’);

210.
Caching Proxy +
Domain hijack

211.
use LWP::Simple;
my $content = get(‘http://localhost:5000/’);

212.
use LWP::Simple;
my $content = get(‘http://london.pm.org/’);

213.
my $app
= Plack::App::Proxy->new(
remote => "http://london.pm.org/" )->to_app;
return builder {
enable "Cache",
match_url => '^/.*', # everything
cache_dir => '/tmp/plack-cache2';
$app;
};

214.
my $app
= Plack::App::Proxy->new(
remote => "http://london.pm.org/" )->to_app;
return builder {
enable "Cache",
match_url => '^/.*', # everything
cache_dir => '/tmp/plack-cache2';
$app;
};

215.
my $app
= Plack::App::Proxy->new(
remote => "http://london.pm.org/" )->to_app;
$app = builder {
enable "Cache",
match_url => '^/.*', # everything
cache_dir => '/tmp/plack-cache2';
$app;
};

216.
# Hijack Any LWP::Useragent requests
LWP::Protocol::PSGI->register($app);
use LWP::Simple;
my $content = get("http://london.pm.org/");
say 'o/' if $content =~ /London Perl Mongers/;

217.
# Hijack Any LWP::Useragent requests
LWP::Protocol::PSGI->register($app);
use LWP::Simple;
my $content = get("http://london.pm.org/");
say 'o/' if $content =~ /London Perl Mongers/;

218.
# Hijack Any LWP::Useragent requests
LWP::Protocol::PSGI->register($app);
use LWP::Simple;
my $content = get("http://london.pm.org/");
say 'o/' if $content =~ /London Perl Mongers/;

219.
# Hijack Any LWP::Useragent requests
LWP::Protocol::PSGI->register($app);
use LWP::Simple;
my $content = get("http://london.pm.org/");
say 'o/' if $content =~ /London Perl Mongers/;

220.
Plack::Test
Unified interface to write TAP tests
with Mock HTTP and Live HTTP

221.
use Plack::Test;
use HTTP::Request::Common;
my $app = sub {
my $env = shift;
return [ $status, $header, $body ];
};
test_psgi
app => $app,
client => sub {
my $callback = shift;
my $req = GET “http://localhost/foo”;
my $res = $callback->($req);
ok $res->[0] == ‘200’, ‘Success’;
};

222.
use Plack::Test;
use HTTP::Request::Common;
my $app = sub {
my $env = shift;
return [ $status, $header, $body ];
};
test_psgi
app => $app,
client => sub {
my $callback = shift;
my $req = GET “http://localhost/foo”;
my $res = $callback->($req);
ok $res->[0] == ‘200’, ‘Success’;
};

223.
use Plack::Test;
use HTTP::Request::Common;
my $app = sub {
my $env = shift;
return [ $status, $header, $body ];
};
test_psgi
app => $app,
client => sub {
my $callback = shift;
my $req = GET “http://localhost/foo”;
my $res = $callback->($req);
ok $res->[0] == ‘200’, ‘Success’;
};

224.
use Plack::Test;
use HTTP::Request::Common;
my $app = sub {
my $env = shift;
return [ $status, $header, $body ];
};
test_psgi
app => $app,
client => sub {
my $callback = shift;
my $req = GET “http://localhost/foo”;
my $res = $callback->($req);
ok $res->[0] == ‘200’, ‘Success’;
};

225.
use Plack::Test;
use HTTP::Request::Common;
my $app = sub {
my $env = shift;
return [ $status, $header, $body ];
};
test_psgi
app => $app,
client => sub {
my $callback = shift;
my $req = GET “http://localhost/foo”;
my $res = $callback->($req);
ok $res->[0] == ‘200’, ‘Success’;
};

226.
use Plack::Test;
use HTTP::Request::Common;
my $app = sub {
my $env = shift;
return [ $status, $header, $body ];
};
test_psgi
app => $app,
client => sub {
my $callback = shift;
my $req = GET “http://localhost/foo”;
my $res = $callback->($req);
ok $res->[0] == ‘200’, ‘Success’;
};

227.
use Plack::Test;
use HTTP::Request::Common;
my $app = sub {
my $env = shift;
return [ $status, $header, $body ];
};
test_psgi
app => $app,
client => sub {
my $callback = shift;
my $req = GET “http://localhost/foo”;
my $res = $callback->($req);
ok $res->[0] == ‘200’, ‘Success’;
};

228.
use Plack::Test;
use HTTP::Request::Common;
my $app = sub {
my $env = shift;
return [ $status, $header, $body ];
};
test_psgi
app => $app,
client => sub {
my $callback = shift;
my $req = GET “http://localhost/foo”;
my $res = $callback->($req);
ok $res->[0] == ‘200’, ‘Success’;
};

229.
Test::WWW::Mechanize::PSGI

230.
use Test::WWW::Mechanize::PSGI;
my $mech =
Test::WWW::Mechanize::PSGI->new(
app => $app,
);
$mech->get_ok('/');

231.
use Test::WWW::Mechanize::PSGI;
my $mech =
Test::WWW::Mechanize::PSGI->new(
app => $app,
);
$mech->get_ok('/');

232.
Testing your full configuration!

233.
Network setup tip

234.
Use a reverse proxy

235.
Use a reverse proxy
• Sits in front of servers, not clients - “reverse”

236.
Use a reverse proxy
• Sits in front of servers, not clients - “reverse”
• Makes servers more efficient

237.
Use a reverse proxy
• Sits in front of servers, not clients - “reverse”
• Makes servers more efficient
• Add HTTPS easily

238.
Use a reverse proxy
• Sits in front of servers, not clients - “reverse”
• Makes servers more efficient
• Add HTTPS easily
• Makes scaling easier

239.
Internet / Users
Webserver App

240.
Internet / Users
Webserver App

241.
Internet / Users
Webserver App

242.
Internet / Users
Webserver App

243.
Internet / Users
Reverse Proxy
NGINX Perlbal Pound
Webserver App

244.
Internet / Users
Reverse Proxy
NGINX Perlbal Pound
Webserver App

245.
Internet / Users
Reverse Proxy
NGINX Perlbal Pound
Webserver App

246.
Internet / Users
Reverse Proxy
NGINX Perlbal Pound
Webserver App

247.
Internet / Users
Reverse Proxy
NGINX Perlbal Pound
Webserver App

248.
Reverse Proxy
NGINX Perlbal Pound
Server

249.
Reverse Proxy
NGINX Perlbal Pound
Server 1 Server 2

250.
Reverse Proxy
NGINX Perlbal Pound
Server 1 Server 3
Server 2

251.
Reverse Proxy
NGINX Perlbal Pound
Server 1 Server 3
Server 2

252.
Plack::Middleware::ReverseProxy
Updates
$env->{REMOTE_ADDRESS}

253.
Why use Plack?

254.
Why use Plack?
‣ Flexibility
‣ Middleware
‣ Apps
‣ Development
‣ Testing
‣ Deployment

255.
Flexibility
Plack::Handler::* (CGI, FCGI, Apache)
Apache lighttpd HTTP::Server::PSGI mod_psgi Perlbal
Starman Twiggy uWSGI Corona etc

256.
Flexibility
• Easy to change webserver (25+!)
Plack::Handler::* (CGI, FCGI, Apache)
Apache lighttpd HTTP::Server::PSGI mod_psgi Perlbal
Starman Twiggy uWSGI Corona etc

257.
Flexibility
• Easy to change webserver (25+!)
Plack::Handler::* (CGI, FCGI, Apache)
Apache lighttpd HTTP::Server::PSGI mod_psgi Perlbal
Starman Twiggy uWSGI Corona etc
• Starman seems to be used most

258.
Middleware

259.
Middleware
• Easy to reuse with any PSGI app

260.
Middleware
• Easy to reuse with any PSGI app
• Many tools to make your life easy

261.
Middleware
• Easy to reuse with any PSGI app
• Many tools to make your life easy
• 160+ on CPAN now

262.
App

263.
App
• URLMapping / Routing

264.
App
• URLMapping / Routing
• Static files

265.
App
• URLMapping / Routing
• Static files
• Proxying

266.
Development

267.
Development
• plackup

268.
Development
• plackup
• Restarter (monitor changes on disk)

269.
Development
• plackup
• Restarter (monitor changes on disk)
• HTTP::Server::PSGI

270.
Development
• plackup
• Restarter (monitor changes on disk)
• HTTP::Server::PSGI
• Debugging middleware

271.
Development
• plackup
• Restarter (monitor changes on disk)
• HTTP::Server::PSGI
• Debugging middleware
• Profiler

272.
Testing

273.
Testing
• Testing your full configuration

274.
Testing
• Testing your full configuration
• Test::WWW::Mechanize::PSGI

275.
Testing
• Testing your full configuration
• Test::WWW::Mechanize::PSGI
• Plack::Test

276.
Deployment

277.
Deployment
• No separate configuration files

278.
Deployment
• No separate configuration files
• Easy to choose/change webserver

279.
Deployment
• No separate configuration files
• Easy to choose/change webserver
• DotCloud etc - cloud deployment

280.
Summary

281.
Summary
✦ PSGI is an interface, Plack is the code.

282.
Summary
✦ PSGI is an interface, Plack is the code.
✦ Many fast PSGI servers.

283.
Summary
✦ PSGI is an interface, Plack is the code.
✦ Many fast PSGI servers.
✦ Adapters and tools for frameworks and
webservers.

284.
Summary
✦ PSGI is an interface, Plack is the code.
✦ Many fast PSGI servers.
✦ Adapters and tools for frameworks and
webservers.
✦ An amazing amount of middleware

285.
Summary
✦ PSGI is an interface, Plack is the code.
✦ Many fast PSGI servers.
✦ Adapters and tools for frameworks and
webservers.
✦ An amazing amount of middleware
✦ Used in many production systems

286.
Use Plack

287.
Thank you!
Slides: http://slideshare.net/ranguard
http://plackperl.org/
irc://irc.perl.org/#plack