3 Catalyst::Manual::Deployment - Deploying Catalyst
9 L<Catalyst::Manual::Deployment::Apache::mod_perl>
15 L<Catalyst::Manual::Deployment::Apache::FastCGI>
18 =head2 mod_perl Deployment
20 mod_perl is not the best solution for many applications, but we'll list some
21 pros and cons so you can decide for yourself. The other (recommended)
22 deployment option is FastCGI, for which see below.
28 mod_perl is fast and your app will be loaded in memory
29 within each Apache process.
31 =head4 Shared memory for multiple apps
33 If you need to run several Catalyst apps on the same server, mod_perl will
34 share the memory for common modules.
40 Since your application is fully loaded in memory, every Apache process will
41 be rather large. This means a large Apache process will be tied up while
42 serving static files, large files, or dealing with slow clients. For this
43 reason, it is best to run a two-tiered web architecture with a lightweight
44 frontend server passing dynamic requests to a large backend mod_perl
49 Any changes made to the core code of your app require a full Apache restart.
50 Catalyst does not support Apache::Reload or StatINC. This is another good
51 reason to run a frontend web server where you can set up an
52 C<ErrorDocument 502> page to report that your app is down for maintenance.
54 =head4 Cannot run multiple versions of the same app
56 It is not possible to run two different versions of the same application in
57 the same Apache instance because the namespaces will collide.
59 =head4 Cannot run different versions of libraries.
61 If you have two different applications which run on the same machine,
62 which need two different versions of a library then the only way to do
63 this is to have per-vhost perl interpreters (with different library paths).
64 This is entirely possible, but nullifies all the memory sharing benefits that
65 you get from having multiple applications sharing the same interpreter.
69 Now that we have that out of the way, let's talk about setting up mod_perl
70 to run a Catalyst app.
72 =head4 1. Install Catalyst::Engine::Apache
74 You should install the latest versions of both Catalyst and
75 Catalyst::Engine::Apache. The Apache engines were separated from the
76 Catalyst core in version 5.50 to allow for updates to the engine without
77 requiring a new Catalyst release.
79 =head4 2. Install Apache with mod_perl
81 Both Apache 1.3 and Apache 2 are supported, although Apache 2 is highly
82 recommended. With Apache 2, make sure you are using the prefork MPM and not
83 the worker MPM. The reason for this is that many Perl modules are not
84 thread-safe and may have problems running within the threaded worker
85 environment. Catalyst is thread-safe however, so if you know what you're
86 doing, you may be able to run using worker.
88 In Debian, the following commands should get you going.
90 apt-get install apache2-mpm-prefork
91 apt-get install libapache2-mod-perl2
93 =head4 3. Configure your application
95 Every Catalyst application will automagically become a mod_perl handler
96 when run within mod_perl. This makes the configuration extremely easy.
97 Here is a basic Apache 2 configuration.
99 PerlSwitches -I/var/www/MyApp/lib
104 PerlResponseHandler MyApp
107 The most important line here is C<PerlModule MyApp>. This causes mod_perl
108 to preload your entire application into shared memory, including all of your
109 controller, model, and view classes and configuration. If you have -Debug
110 mode enabled, you will see the startup output scroll by when you first
113 For an example Apache 1.3 configuration, please see the documentation for
114 L<Catalyst::Engine::Apache::MP13>.
118 That's it, your app is now a full-fledged mod_perl application! Try it out
119 by going to http://your.server.com/.
123 =head4 Non-root location
125 You may not always want to run your app at the root of your server or virtual
126 host. In this case, it's a simple change to run at any non-root location
131 PerlResponseHandler MyApp
134 When running this way, it is best to make use of the C<uri_for> method in
135 Catalyst for constructing correct links.
137 =head4 Static file handling
139 Static files can be served directly by Apache for a performance boost.
141 DocumentRoot /var/www/MyApp/root
143 SetHandler default-handler
146 This will let all files within root/static be handled directly by Apache. In
147 a two-tiered setup, the frontend server should handle static files.
148 The configuration to do this on the frontend will vary.
150 The same is accomplished in lighttpd with the following snippet:
152 $HTTP["url"] !~ "^/(?:img/|static/|css/|favicon.ico$)" {
156 "socket" => "/tmp/myapp.socket",
157 "check-local" => "disable",
163 Which serves everything in the img, static, css directories
164 statically, as well as the favicon file.
166 Note the path of the application needs to be stated explicitly in the
167 web server configuration for both these recipes.
169 =head2 Catalyst on shared hosting
171 So, you want to put your Catalyst app out there for the whole world to
172 see, but you don't want to break the bank. There is an answer - if you
173 can get shared hosting with FastCGI and a shell, you can install your
174 Catalyst app in a local directory on your shared host. First, run
178 and go through the standard CPAN configuration process. Then exit out
179 without installing anything. Next, open your .bashrc and add
181 export PATH=$HOME/local/bin:$HOME/local/script:$PATH
182 perlversion=`perl -v | grep 'built for' | awk '{print $4}' | sed -e 's/v//;'`
183 export PERL5LIB=$HOME/local/share/perl/$perlversion:$HOME/local/lib/perl/$perlversion:$HOME/local/lib:$PERL5LIB
185 and log out, then back in again (or run C<". .bashrc"> if you
186 prefer). Finally, edit C<.cpan/CPAN/MyConfig.pm> and add
188 'make_install_arg' => qq[SITEPREFIX=$ENV{HOME}/local],
189 'makepl_arg' => qq[INSTALLDIRS=site install_base=$ENV{HOME}/local],
191 Now you can install the modules you need using CPAN as normal; they
192 will be installed into your local directory, and perl will pick them
193 up. Finally, change directory into the root of your virtual host and
194 symlink your application's script directory in:
196 cd path/to/mydomain.com
197 ln -s ~/lib/MyApp/script script
199 And add the following lines to your .htaccess file (assuming the server
200 is setup to handle .pl as fcgi - you may need to rename the script to
201 myapp_fastcgi.fcgi and/or use a SetHandler directive):
204 RewriteCond %{REQUEST_URI} !^/?script/myapp_fastcgi.pl
205 RewriteRule ^(.*)$ script/myapp_fastcgi.pl/$1 [PT,L]
207 Now C<http://mydomain.com/> should now Just Work. Congratulations, now
208 you can tell your friends about your new website (or in our case, tell
209 the client it's time to pay the invoice :) )
211 =head2 FastCGI Deployment
213 FastCGI is a high-performance extension to CGI. It is suitable
214 for production environments.
220 FastCGI performs equally as well as mod_perl. Don't let the 'CGI' fool you;
221 your app runs as multiple persistent processes ready to receive connections
226 When using external FastCGI servers, your application runs as a standalone
227 application server. It may be restarted independently from the web server.
228 This allows for a more robust environment and faster reload times when
229 pushing new app changes. The frontend server can even be configured to
230 display a friendly "down for maintenance" page while the application is
233 =head4 Load-balancing
235 You can launch your application on multiple backend servers and allow the
236 frontend web server to load-balance between all of them. And of course, if
237 one goes down, your app continues to run fine.
239 =head4 Multiple versions of the same app
241 Each FastCGI application is a separate process, so you can run different
242 versions of the same app on a single server.
244 =head4 Can run with threaded Apache
246 Since your app is not running inside of Apache, the faster mpm_worker module
247 can be used without worrying about the thread safety of your application.
251 You may have to disable mod_deflate. If you experience page hangs with
252 mod_fastcgi then remove deflate.load and deflate.conf from mods-enabled/
254 =head4 More complex environment
256 With FastCGI, there are more things to monitor and more processes running
257 than when using mod_perl.
261 =head4 1. Install Apache with mod_fastcgi
263 mod_fastcgi for Apache is a third party module, and can be found at
264 L<http://www.fastcgi.com/>. It is also packaged in many distributions,
265 for example, libapache2-mod-fastcgi in Debian. You will also need to install
266 the L<FCGI> module from cpan.
268 Important Note! If you experience difficulty properly rendering pages,
269 try disabling Apache's mod_deflate (Deflate Module), e.g. 'a2dismod deflate'.
271 =head4 2. Configure your application
273 # Serve static content directly
274 DocumentRoot /var/www/MyApp/root
275 Alias /static /var/www/MyApp/root/static
277 FastCgiServer /var/www/MyApp/script/myapp_fastcgi.pl -processes 3
278 Alias /myapp/ /var/www/MyApp/script/myapp_fastcgi.pl/
280 # Or, run at the root
281 Alias / /var/www/MyApp/script/myapp_fastcgi.pl/
283 The above commands will launch 3 app processes and make the app available at
286 =head3 Standalone server mode
288 While not as easy as the previous method, running your app as an external
289 server gives you much more flexibility.
291 First, launch your app as a standalone server listening on a socket.
293 script/myapp_fastcgi.pl -l /tmp/myapp.socket -n 5 -p /tmp/myapp.pid -d
295 You can also listen on a TCP port if your web server is not on the same
298 script/myapp_fastcgi.pl -l :8080 -n 5 -p /tmp/myapp.pid -d
300 You will probably want to write an init script to handle starting/stopping
301 of the app using the pid file.
303 Now, we simply configure Apache to connect to the running server.
305 # 502 is a Bad Gateway error, and will occur if the backend server is down
306 # This allows us to display a friendly static page that says "down for
308 Alias /_errors /var/www/MyApp/root/error-pages
309 ErrorDocument 502 /_errors/502.html
311 FastCgiExternalServer /tmp/myapp.fcgi -socket /tmp/myapp.socket
312 Alias /myapp/ /tmp/myapp.fcgi/
314 # Or, run at the root
315 Alias / /tmp/myapp.fcgi/
319 L<Catalyst::Engine::FastCGI>.
321 =head2 Development server deployment
323 The development server is a mini web server written in perl. If you
324 expect a low number of hits or you don't need mod_perl/FastCGI speed,
325 you could use the development server as the application server with a
326 lightweight proxy web server at the front. However, consider using
327 L<Catalyst::Engine::HTTP::Prefork> for this kind of deployment instead, since
328 it can better handle multiple concurrent requests without forking, or can
329 prefork a set number of servers for improved performance.
333 As this is an application server setup, the pros are the same as
334 FastCGI (with the exception of speed).
339 The development server is what you create your code on, so if it works
340 here, it should work in production!
346 Not as fast as mod_perl or FastCGI. Needs to fork for each request
347 that comes in - make sure static files are served by the web server to
352 =head4 Start up the development server
354 script/myapp_server.pl -p 8080 -k -f -pidfile=/tmp/myapp.pid
356 You will probably want to write an init script to handle stop/starting
357 the app using the pid file.
359 =head4 Configuring Apache
361 Make sure mod_proxy is enabled and add:
363 # Serve static content directly
364 DocumentRoot /var/www/MyApp/root
365 Alias /static /var/www/MyApp/root/static
373 # Need to specifically stop these paths from being passed to proxy
375 ProxyPass /favicon.ico !
377 ProxyPass / http://localhost:8080/
378 ProxyPassReverse / http://localhost:8080/
380 # This is optional if you'd like to show a custom error page
381 # if the proxy is not available
382 ErrorDocument 502 /static/error_pages/http502.html
384 You can wrap the above within a VirtualHost container if you want
385 different apps served on the same host.
389 Catalyst Contributors, see Catalyst.pm
393 This library is free software. You can redistribute it and/or modify it under
394 the same terms as Perl itself.