1Dancer2::Manual::DeployUmseenrt(C3o)ntributed Perl DocumDeanntcaetri2o:n:Manual::Deployment(3)
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NAME

6       Dancer2::Manual::Deployment - common ways to put your Dancer app into
7       use
8

VERSION

10       version 0.300005
11

DESCRIPTION

13       Dancer has been designed to be flexible, and this flexibility extends
14       to your choices when deploying your Dancer app.
15
16   Running stand-alone
17       To start your application, just run plackup:
18
19           $ plackup bin/app.psgi
20           HTTP::Server::PSGI: Accepting connections at http://0:5000/
21
22       Point your browser at it, and away you go!
23
24       This option can be useful for small personal web apps or internal apps,
25       but if you want to make your app available to the world, it probably
26       won't suit you.
27
28       Auto Reloading the Application
29
30       While developing your application, it is often handy to have the server
31       automatically reload your application when changes are made. There are
32       two recommended ways of handling this with Dancer: using " plackup -r "
33       and Plack::Loader::Shotgun. Both have their advantages and
34       disadvantages (which will be explained below).
35
36       Regardless of the method you use, it is  not  recommended that you
37       automatically reload your applications in a production environment, for
38       reasons of performance, deployment best practices, etc.
39
40       For Dancer 1 programmers that used the " auto_reload " option, please
41       use one of these alternatives instead:
42
43       Auto reloading with " plackup -r "
44
45       Plack's built-in reloader will reload your application anytime a file
46       in your application's directory (usually,  /bin ) changes. You will
47       likely want to monitor your  lib/  directory too, using the " -R "
48       option:
49
50           $ plackup -r -R lib bin/app.psgi
51
52       There is a performance hit associated with this, as Plack will spin off
53       a separate process that monitors files in the application and other
54       specified directories. If the timestamp of any files in a watched
55       directory changes, the application is recompiled and reloaded.
56
57       See the plackup docs for more information on the " -r " and " -R "
58       options.
59
60       Auto reloading with plackup and Shotgun
61
62       There may be circumstances where Plack's built-in reloader won't work
63       for you, be it for the way it looks for changes, or because there are
64       many directories you need to monitor, or you want to reload the
65       application any time one of the modules in Perl's  lib/  path changes.
66       Plack::Loader::Shotgun makes this easy by recompiling the application
67       on every request.
68
69       To use Shotgun, specify it using the loader argument to " plackup (-L)
70       ":
71
72           $ plackup -L Shotgun bin/app.psgi
73
74       The Shotgun, while effective, can quickly cause you performance issues,
75       even during the development phase of your application. As the number of
76       plugins you use in your application grows, as the number of static
77       resources (images, etc.) grows, the more requests your server process
78       needs to handle. Since each request recompiles the application, even
79       simple page refreshes can get unbearably slow over time. Use with
80       caution.
81
82       You can bypass Shotgun's auto-reloading of specific modules with the "
83       -M " switch:
84
85           $ plackup -L Shotgun -M<MyApp::Foo> -M<MyApp::Bar> bin/app.psgi
86
87       On Windows, Shotgun loader is known to cause huge memory leaks in a
88       fork-emulation layer. If you are aware of this and still want to run
89       the loader, please use the following command:
90
91           > set PLACK_SHOTGUN_MEMORY_LEAK=1 && plackup -L Shotgun bin\app.psgi
92           HTTP::Server::PSGI: Accepting connections at http://0:5000/
93
94       Please note:  if you are using Dancer 2's asynchronous capabilities,
95       using Shotgun will kill Twiggy. If you need async processing, consider
96       an alternative to Shotgun.
97
98   Running under Apache
99       You can run your Dancer app from Apache using the following examples:
100
101       As a CGI script
102
103       In its simplest form, your Dancer app can be run as a simple CGI script
104       out-of-the-box. You will need to enable the Apache mod_cgi or mod_cgid
105       modules ("a2enmod cgi" or "a2enmod cgid" on Debian-based systems) and
106       mod_rewrite ("a2enmod rewrite"). The Perl module Plack::Runner is
107       required.
108
109       The following is an example apache configuration. Depending on your
110       Apache configuration layout, this should be placed in "httpd.conf" or
111       "sites-available/*site*". The configuration options can also be placed
112       in ".htaccess" files if you prefer.
113
114           <VirtualHost *:80>
115               ServerName www.example.com
116
117               # /srv/www.example.com is the root of your
118               # dancer application
119               DocumentRoot /srv/www.example.com/public
120
121               ServerAdmin you@example.com
122
123               <Directory "/srv/www.example.com/public">
124                   AllowOverride None
125                   Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch
126                   AddHandler cgi-script .cgi
127                   # Apache 2.2
128                   Order allow,deny
129                   Allow from all
130                   # Apache 2.4
131                   Require all granted
132               </Directory>
133
134               RewriteEngine On
135               RewriteCond %{REQUEST_FILENAME} !-f
136               RewriteRule ^(.*)$ /dispatch.cgi$1 [QSA,L]
137
138               ErrorLog  /var/log/apache2/www.example.com-error.log
139               CustomLog /var/log/apache2/www.example.com-access_log common
140           </VirtualHost>
141
142       Now you can access your dancer application URLs as if you were using
143       the embedded web server.
144
145           http://www.example.com/
146
147       This option is a no-brainer, easy to setup and low maintenance, but
148       serves requests slower than all other options, as each time a request
149       is made to your server, Apache will start your application. This might
150       be suitable for a small, occasionally-used sites, as the application is
151       not using resources when it is not being accessed. For anything more,
152       you probably want to use FastCGI instead (see next section).
153
154       To list all currently loaded modules, type "apachectl -M" ("apache2ctl
155       -M" on Debian/Ubuntu).
156
157       As a FastCGI script
158
159       This has all the easy-to-setup and low-maintenance advantages of CGI,
160       but is much faster for each request, as it keeps a copy of the
161       application running all the time.
162
163       You will still need to enable "mod_rewrite", but will need to use a
164       FastCGI module instead of a CGI module. There are 3 available:
165       mod_fcgid <http://httpd.apache.org/mod_fcgid/>, mod_fastcgi
166       <http://www.fastcgi.com/> and mod_proxy_fcgi
167       <https://httpd.apache.org/docs/trunk/mod/mod_proxy_fcgi.html>.  For
168       this example, we will use mod_fastcgi ("a2enmod fastcgi" in Debian).
169
170       The CGI configuration above now changes as follows (differences
171       highlighted with XXX):
172
173           <VirtualHost *:80>
174               ServerName www.example.com
175
176               # /srv/www.example.com is the root of your
177               # dancer application
178               DocumentRoot /srv/www.example.com/public
179
180               ServerAdmin you@example.com
181
182               # XXX Start a FastCGI server to run in the background
183               FastCgiServer /srv/www.example.com/public/dispatch.fcgi
184
185               <Directory "/srv/www.example.com/public">
186                   AllowOverride None
187                   Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch
188                   # XXX Use FastCGI handler instead of CGI
189                   AddHandler fastcgi-script .fcgi
190                   # Apache 2.2
191                   Order allow,deny
192                   Allow from all
193                   # Apache 2.4
194                   Require all granted
195               </Directory>
196
197               RewriteEngine On
198               RewriteCond %{REQUEST_FILENAME} !-f
199               # Run FastCGI dispatcher instead of CGI dispatcher
200               RewriteRule ^(.*)$ /dispatch.fcgi$1 [QSA,L]
201
202               ErrorLog  /var/log/apache2/www.example.com-error.log
203               CustomLog /var/log/apache2/www.example.com-access_log common
204           </VirtualHost>
205
206       This is the easiest way to get a production server up and running, as
207       there is no need to worry about daemonizing your application. Apache
208       manages all that for you.
209
210       Reloading your application
211
212       You can use "apache2ctl restart" or "apache2ctl graceful" to reload
213       your application. The latter will be more friendly to your users in a
214       production environment. If your application loads relatively quickly,
215       then it should go unnoticed.
216
217       Configuration
218
219       See <http://www.fastcgi.com/mod_fastcgi/docs/mod_fastcgi.html> for
220       FastCGI configuration options. An example configuration:
221
222          FastCgiServer /srv/www.example.com/public/dispatch.fcgi -processes 5 -initial-env DANCER_ENVIRONMENT="production"
223
224       With Plack
225
226       You can run your app from Apache using PSGI (Plack), with a config like
227       the following:
228
229           <VirtualHost myapp.example.com>
230               ServerName www.myapp.example.com
231               ServerAlias myapp.example.com
232               DocumentRoot /websites/myapp.example.com
233
234               <Directory /home/myapp/myapp>
235                   AllowOverride None
236                   Order allow,deny
237                   Allow from all
238               </Directory>
239
240               <Location />
241                   SetHandler perl-script
242                   PerlResponseHandler Plack::Handler::Apache2
243                   PerlSetVar psgi_app /websites/myapp.example.com/app.psgi
244               </Location>
245
246               ErrorLog  /websites/myapp.example.com/logs/error_log
247               CustomLog /websites/myapp.example.com/logs/access_log common
248           </VirtualHost>
249
250       To set the environment you want to use for your application (production
251       or development), you can set it this way:
252
253           <VirtualHost>
254               ...
255               SetEnv DANCER_ENVIRONMENT "production"
256               ...
257           </VirtualHost>
258
259       Running multiple applications under the same virtualhost
260
261       If you want to deploy multiple applications under the same
262       "VirtualHost" (using one application per directory, for example) you
263       can use the following example Apache configuration.
264
265       This example uses the FastCGI dispatcher that comes with Dancer, but
266       you should be able to adapt this to use any other way of deployment
267       described in this guide. The only purpose of this example is to show
268       how to deploy multiple applications under the same base
269       directory/virtualhost.
270
271           <VirtualHost *:80>
272               ServerName localhost
273               DocumentRoot "/path/to/rootdir"
274               RewriteEngine On
275               RewriteCond %{REQUEST_FILENAME} !-f
276
277               <Directory "/path/to/rootdir">
278                   AllowOverride None
279                   Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch
280                   Order allow,deny
281                   Allow from all
282                   AddHandler fastcgi-script .fcgi
283               </Directory>
284
285               RewriteRule /App1(.*)$ /App1/public/dispatch.fcgi$1 [QSA,L]
286               RewriteRule /App2(.*)$ /App2/public/dispatch.fcgi$1 [QSA,L]
287               ...
288               RewriteRule /AppN(.*)$ /AppN/public/dispatch.fcgi$1 [QSA,L]
289           </VirtualHost>
290
291       Of course, if your Apache configuration allows that, you can put the
292       RewriteRules in a .htaccess file directly within the application's
293       directory, which lets you add a new application without changing the
294       Apache configuration.
295
296   Running on PSGI-based Perl webservers
297       A number of Perl web servers supporting PSGI are available on cpan:
298
299       Starman
300           "Starman" is a high performance web server, with support for
301           preforking, signals, multiple interfaces, graceful restarts and
302           dynamic worker pool configuration.
303
304       Twiggy
305           "Twiggy" is an "AnyEvent" web server, it's light and fast.
306
307       Corona
308           "Corona" is a "Coro" based web server.
309
310       Similar to running standalone, use plackup to start your application
311       (see Plack and specific servers above for all available options):
312
313           $ plackup bin/app.psgi
314           $ plackup -E deployment -s Starman --workers=10 -p 5001 -a bin/app.psgi
315
316       As you can see, the scaffolded Perl script for your app can be used as
317       a PSGI startup file.
318
319       Enabling content compression
320
321       Content compression (gzip, deflate) can be easily enabled via a Plack
322       middleware (see "Plack::Middleware" in Plack):
323       Plack::Middleware::Deflater.  It's a middleware to encode the response
324       body in gzip or deflate, based on the "Accept-Encoding" HTTP request
325       header.
326
327       Enable it as you would enable any Plack middleware. First you need to
328       install Plack::Middleware::Deflater, then in the handler (usually
329       app.psgi) edit it to use Plack::Builder, as described above:
330
331           use Dancer2;
332           use MyWebApp;
333           use Plack::Builder;
334
335           builder {
336               enable 'Deflater';
337               dance;
338           };
339
340       To test if content compression works, trace the HTTP request and
341       response before and after enabling this middleware. Among other things,
342       you should notice that the response is gzip or deflate encoded, and
343       contains a header "Content-Encoding" set to "gzip" or "deflate".
344
345       Creating a service
346
347       You can turn your app into proper service running in background using
348       one of the following examples:
349
350       Using Ubic
351
352       Ubic is an extensible perlish service manager. You can use it to start
353       and stop any services, automatically start them on reboots or daemon
354       failures, and implement custom status checks.
355
356       A basic PSGI service description (usually in
357       "/etc/ubic/service/application"):
358
359           use parent qw(Ubic::Service::Plack);
360
361           # if your application is not installed in @INC path:
362           sub start {
363               my $self = shift;
364               $ENV{PERL5LIB} = '/path/to/your/application/lib';
365               $self->SUPER::start(@_);
366           }
367
368           __PACKAGE__->new(
369               server => 'Starman',
370               app => '/path/to/your/application/app.psgi',
371               port => 5000,
372               user => 'www-data',
373           );
374
375       Run "ubic start application" to start the service.
376
377       Using daemontools
378
379       daemontools is a collection of tools for managing UNIX services. You
380       can use it to easily start/restart/stop services.
381
382       A basic script to start an application: (in "/service/application/run")
383
384           #!/bin/sh
385
386           # if your application is not installed in @INC path:
387           export PERL5LIB='/path/to/your/application/lib'
388
389           exec 2>&1 \
390           /usr/local/bin/plackup -s Starman -a /path/to/your/application/app.psgi -p 5000
391
392   Running stand-alone behind a proxy / load balancer
393       Another option would be to run your app stand-alone as described above,
394       but then use a proxy or load balancer to accept incoming requests (on
395       the standard port 80, say) and feed them to your Dancer app. Also, in
396       this case you might want to look at the "behind_proxy" configuration
397       option, to make sure that all the URLs are constructed properly.
398
399           behind_proxy: 1
400
401       This setup can be achieved using various software; examples would
402       include:
403
404       Using Apache's mod_proxy
405
406       You could set up a "VirtualHost" for your web app, and proxy all
407       requests through to it:
408
409           <VirtualHost mywebapp.example.com:80>
410           ProxyPass / http://localhost:3000/
411           ProxyPassReverse / http://localhost:3000/
412           </VirtualHost>
413
414       Or, if you want your webapp to share an existing VirtualHost, you could
415       have it under a specified dir:
416
417           ProxyPass /mywebapp/ http://localhost:3000/
418           ProxyPassReverse /mywebapp/ http://localhost:3000/
419
420       It is important for you to note that the Apache2 modules "mod_proxy"
421       and "mod_proxy_http" must be enabled:
422
423           $ a2enmod proxy
424           $ a2enmod proxy_http
425
426       It is also important to set permissions for proxying for security
427       purposes, below is an example.
428
429           <Proxy *>
430             Order allow,deny
431             Allow from all
432           </Proxy>
433
434       Using perlbal
435
436       "Perlbal" is a single-threaded event-based server written in Perl
437       supporting HTTP load balancing, web serving, and a mix of the two,
438       available from <http://www.danga.com/perlbal/>
439
440       It processes hundreds of millions of requests a day just for
441       LiveJournal, Vox and TypePad and dozens of other "Web 2.0"
442       applications.
443
444       It can also provide a management interface to let you see various
445       information on requests handled etc.
446
447       It could easily be used to handle requests for your Dancer apps, too.
448
449       It can be easily installed from CPAN:
450
451           perl -MCPAN -e 'install Perlbal'
452
453       Once installed, you'll need to write a configuration file.  See the
454       examples provided with perlbal, but you'll probably want something
455       like:
456
457           CREATE POOL my_dancers
458           POOL my_dancers ADD 10.0.0.10:3030
459           POOL my_dancers ADD 10.0.0.11:3030
460           POOL my_dancers ADD 10.0.0.12:3030
461           POOL my_dancers ADD 10.0.0.13:3030
462
463           CREATE SERVICE my_webapp
464           SET listen          = 0.0.0.0:80
465           SET role            = reverse_proxy
466           SET pool            = my_dancers
467           SET persist_client  = on
468           SET persist_backend = on
469           SET verify_backend  = on
470           ENABLE my_webapp
471
472       Using balance
473
474       "balance" is a simple load-balancer from Inlab Software, available from
475       <http://www.inlab.de/balance.html>.
476
477       It could be used simply to hand requests to a standalone Dancer app.
478       You could even run several instances of your Dancer app, on the same
479       machine or on several machines, and use a machine running "balance" to
480       distribute the requests between them, for some serious heavy traffic
481       handling!
482
483       To listen on port 80, and send requests to a Dancer app on port 3000:
484
485           balance http localhost:3000
486
487       To listen on a specified IP only on port 80, and distribute requests
488       between multiple Dancer apps on multiple other machines:
489
490           balance -b 10.0.0.1 80 10.0.0.2:3000 10.0.0.3:3000 10.0.0.4:3000
491
492       Using Lighttpd
493
494       You can use Lighttp's "mod_proxy":
495
496           $HTTP["url"] =~ "/application" {
497               proxy.server = (
498                   "/" => (
499                       "application" => ( "host" => "127.0.0.1", "port" => 3000 )
500                   )
501               )
502           }
503
504       This configuration will proxy all request to the /application path to
505       the path / on localhost:3000.
506
507       Using Nginx
508
509       with Nginx:
510
511           upstream backendurl {
512               server unix:THE_PATH_OF_YOUR_PLACKUP_SOCKET_HERE.sock;
513           }
514
515           server {
516             listen       80;
517             server_name YOUR_HOST_HERE;
518
519             access_log /var/log/YOUR_ACCESS_LOG_HERE.log;
520             error_log  /var/log/YOUR_ERROR_LOG_HERE.log info;
521
522             root YOUR_ROOT_PROJECT/public;
523             location / {
524               try_files $uri @proxy;
525               access_log off;
526               expires max;
527             }
528
529             location @proxy {
530                   proxy_set_header Host $http_host;
531                   proxy_set_header X-Forwarded-Host $host;
532                   proxy_set_header X-Real-IP $remote_addr;
533                   proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
534                   proxy_pass       http://backendurl;
535             }
536
537           }
538
539       You will need plackup to start a worker listening on a socket :
540
541           cd YOUR_PROJECT_PATH
542           sudo -u www plackup -E production -s Starman --workers=2 -l THE_PATH_OF_YOUR_PLACKUP_SOCKET_HERE.sock -a bin/app.pl
543
544       A good way to start this is to use "daemontools" and place this line
545       with all environments variables in the "run" file.
546
547       Using HAProxy
548
549       "HAProxy" is a reliable high-performance TCP/HTTP load balancer written
550       in C available from <https://www.haproxy.org/>.
551
552       Suppose we want to run an application at "app.example.com:80" and would
553       to use two backends listen on hosts "app-be1.example.com:3000" and
554       "app-be2.example.com:3000".
555
556       Here is HAProxy configuration file (haproxy.conf):
557
558           global
559               nbproc  1
560               maxconn 4096
561               user    nobody
562               group   nobody
563               # haproxy logs will be collected by syslog
564               # syslog: unix socket path or tcp pair (ipaddress:port)
565               log     /var/run/log local0
566               daemon
567               # enable compression (haproxy v1.5-dev13 and above required)
568               tune.comp.maxlevel  5
569
570           defaults
571               log     global
572               option  httpclose
573               option  httplog
574               option  dontlognull
575               option  forwardfor
576               option  abortonclose
577               mode    http
578               balance roundrobin
579               retries 3
580               timeout connect         5s
581               timeout server          30s
582               timeout client          30s
583               timeout http-keep-alive 200m
584               # enable compression (haproxy v1.5-dev13 and above required)
585               compression algo gzip
586               compression type text/html application/javascript text/css application/x-javascript text/javascript
587
588           # application frontend (available at http://app.example.com)
589           frontend app.example.com
590               bind                  :80
591               # modify request headers
592               reqadd                X-Forwarded-Proto:\ http
593               reqadd                X-Forwarded-Port:\ 80
594               # modify response headers
595               rspdel                ^Server:.*
596               rspdel                ^X-Powered-By:.*
597               rspadd                Server:\ Dethklok\ (Unix/0.2.3)
598               rate-limit sessions   1024
599               acl is-haproxy-stats  path_beg /stats
600               # uncomment if you'd like to get haproxy usage statistics
601               # use_backend haproxy   if is-haproxy-stats
602               default_backend       dynamic
603
604           # haproxy statistics (available at http://app.example.com/stats)
605           backend haproxy
606               stats uri             /stats
607               stats refresh         180s
608               stats realm           app.example.com\ haproxy\ statistics
609               # change credentials
610               stats auth            admin1:password1
611               stats auth            admin2:password2
612               stats hide-version
613               stats show-legends
614
615           # application backends
616           backend dynamic
617               # change path_info to check and value of the Host header sent to application server
618               option httpchk HEAD / HTTP/1.1\r\nHost:\ app.example.com
619               server app1 app-be1.example.com:3000 check inter 30s
620               server app2 app-be2.example.com:3000 check inter 30s
621
622       We will need to start the workers on each backend of our application.
623       This can be done by starman utility:
624
625           # on app-be1.example.com
626           $ starman --workers=2 --listen :3000 /path/to/app.pl
627           # on app-be2.example.com
628           $ starman --workers=2 --listen :3000 /path/to/app.pl
629
630       Then start the haproxy itself:
631
632           # check the configuration..
633           $ sudo haproxy -c -f haproxy.conf
634           # now really start it..
635           $ sudo haproxy -f haproxy.conf
636
637   Running on lighttpd
638       Running on lighttpd (CGI)
639
640       To run as a CGI app on lighttpd, just create a soft link to the
641       "dispatch.cgi" script (created when you run "dancer -a MyApp") inside
642       your system's "cgi-bin" folder. Make sure "mod_cgi" is enabled.
643
644           ln -s /path/to/MyApp/public/dispatch.cgi /usr/lib/cgi-bin/mycoolapp.cgi
645
646       Running on lighttpd (FastCGI)
647
648       Make sure "mod_fcgi" is enabled. You also must have FCGI installed.
649
650       This example configuration uses TCP/IP:
651
652           $HTTP["url"] == "^/app" {
653               fastcgi.server += (
654                   "/app" => (
655                       "" => (
656                           "host" => "127.0.0.1",
657                           "port" => "5000",
658                           "check-local" => "disable",
659                       )
660                   )
661               )
662           }
663
664       Launch your application:
665
666           plackup -s FCGI --port 5000 bin/app.psgi
667
668       This example configuration uses a socket:
669
670           $HTTP["url"] =~ "^/app" {
671               fastcgi.server += (
672                   "/app" => (
673                       "" => (
674                           "socket" => "/tmp/fcgi.sock",
675                           "check-local" => "disable",
676                       )
677                   )
678               )
679           }
680
681       Launch your application:
682
683           plackup -s FCGI --listen /tmp/fcgi.sock bin/app.psgi
684
685   Performance Improvements
686       The following modules can be used to speed up an app in Dancer2:
687
688       •   URL::Encode::XS
689
690       •   CGI::Deurl::XS
691
692       •   HTTP::Parser::XS
693
694       •   HTTP::XSCookies
695
696       •   Scope::Upper
697
698       •   Type::Tiny::XS
699
700       They would need to be installed separately. This is because Dancer2
701       does not incorporate any C code, but it can get C-code compiled as a
702       module.  Thus, these modules can be used for speed improvement
703       provided:
704
705       •   You have access to a C interpreter
706
707       •   You don't need to fatpack your application
708

AUTHOR

710       Dancer Core Developers
711
713       This software is copyright (c) 2021 by Alexis Sukrieh.
714
715       This is free software; you can redistribute it and/or modify it under
716       the same terms as the Perl 5 programming language system itself.
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718
719
720perl v5.32.1                      2021-01-31    Dancer2::Manual::Deployment(3)
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