Ubuntu Manpage: Jifty::Manual::Deploying - Deploying your application for production use

Provided by: libjifty-perl_1.10518+dfsg-3ubuntu1_all

NAME

       Jifty::Manual::Deploying - Deploying your application for production use

DESCRIPTION

       This document is intended to answer two questions:

       •   Now that you've developed your Jifty application, how do you deploy it on the production server?

       •   Once deployed, what's the process for performing upgrades to the production server?

       Developers  and  administrators  may  wish  to  use  this  document  as a checklist to make sure they hit
       everything when deploying. This document should be updated according  to  the  best  practices  of  Jifty
       deployment to aid this end.

HOW TO

Installing on a Production Server
Once you've finished developing your Jifty application and you want to deploy it for use on a production
server you'll need to follow these steps:

1. Install Jifty on your production server.

2. Copy your application onto the production server.

3. Adjust the configuration to suit your production environment.

4. Deploy your production database.

5. Configure your web server.

6. Start using your production service.

Install Jifty

Jifty installation proceeds just as it did on your development machine (or machines). If you installed
from CPAN, you may do the same for your production server.

perl -MCPAN -e 'install Jifty'

or download Jifty and run:

tar zxf Jifty-VERSION.tar.gz
cd Jifty-VERSION
perl Makefile.PL
make
make test
sudo make install

You may also have installed it via the package manager available for your Linux distribution.

Finally, you may want to use bleeding-edge features available only in the Jifty Subversion repository.
This has a slightly higher risk, but this is what the Best Practical team does for their Jifty
applications. When doing this, you will probably want to be sure to check out the exact same version as
you are using on your development machines.

Be sure to run the tests when installing Jifty to make sure there aren't any problems on your production
server that you need to fix before deploying your application.

Copy the Application

After you've gotten Jifty deployed, you need to copy your application onto the server. This can be done
in whatever way suits your project. You can run your Jifty application straight out of the development
directory just as you have on testing. Just place the directory into an appropriate location on your
server.

It may be advisable to consider using a version control system, such as SVK or Subversion, to aid you in
this process. For example, with either SVK or Subversion, any production customizations can be handled as
branches of your application to help you keep those changes sorted out clearly. This can also help you if
you make any tweaks to the code on the production server that need to be put back into your development.

Here is an example of how to create the branch in Subversion or. This example is built upon in the
"Upgrading the Production Server" section below.

All these commands are assumed to be running on the production server in this example, but you could do
much of these from anywhere.

svn mkdir http://svn.example.com/myapp/branches
svn copy http://svn.example.com/myapp/trunk \
http://svn.example.com/myapp/branches/production
svn checkout http://svn.example.com/myapp/branches/production \
myapp
cd myapp

Make sure to remember (possibly by recording it in the log messages) which revision your trunk was at
when you ran the copy command. This will be important later. If you're using SVK rather than Subversion,
you don't have to worry about this.

In SVK:

svk mkdir //myapp/branches
svk copy //myapp/trunk //myapp/branches/production
svk checkout //myapp/branches/production myapp
cd myapp

You will now have a copy of the latest version of your project in the directory named myapp. You can then
make any of the modifications you need to to get your application configured for the production
environment (read the following sections for details).

When you're finished, commit those changes to the branch:

svn commit

or in SVK:

svk commit

All of these changes will be made only to the production branch. In the upgrade section, it will be
clearer how this will help you.

Tweak the Configuration

After you've copied your application onto the server, change into that directory and make any changes to
your configuration required for production.

Put all your site-specific changes in etc/site_config.yml and never edit etc/config.yml, as it will be
overwritten with the next application update.

Here are some things you'll want to consider changing:

AdminMode
While developing, you'll probably want to try running your application with this turned off. This
turns on the administrative functions for managing models, data, and actions.

Set this to 0 to turn it off.

Database
These settings will be covered in more detail in "Deploy the Database".

DevelMode
This turns off certain checks that slow down a production system but are vital to fast development.
For example, with ever request to a server with "DevelMode" turned on, the server checks to see if
any of the library or template files have changed and reloads them, if this is turned on.

By switching this setting off, you also enable extra caching and speed-up features including the use
of CSS::Squish, which helps your application load CSS files more quickly.

LogConfig
You may wish to add this option to specify a custom logger configuration. See Jifty::Logger.

LogLevel
Depending on your environment, you may want to adjust the default log level or you may want to
customize the log configuration by introducing an etc/log4perl.conf configuration file.

You can set the LogLevel to: DEBUG, INFO, WARN, ERROR, or FATAL to specify the level. If you want a
custom log configuration for your server (allowing you to have per-module log settings among other
features), you need to set "LogConfig" and possibly "LogReload". See Jifty::Logger

This configuration setting is overridden by the JIFTY_LOG_LEVEL environment variable (if set).

LogReload
This allows you specify a custom reload period for your log configuration, if you use "LogConfig".
See Jifty::Logger.

Mailer
In some cases you will want to adjust the mailer configuration used by Jifty. The mail configuration
is used whenever Jifty::Notification messages are sent, which may or may not be used by your
application.

If you change the "Mailer" setting, be sure to also change "MailerArgs" to match.

See Jifty::Notification and Email::Send.

MailerArgs
You may want to adjust the configuration of the mailer you are using. See Jifty::Notification and
Email::Send.

Plugins
You may want to disable plugins you've been using in your development that you don't need in
production. In general, if these plugins are well-behaved this isn't necessary, but you can provide
yourself with extra insurance in case they are not.

You can disable them without removing them from the file by commenting them out using the Perl-style
"#" comment mark.

Web
BaseURL
You will want to change the "BaseURL" setting under "Web" to make sure it shows the name of your
production server's base URL.

ServeStaticFiles
If you want to improve the performance of your server, you may want your main web server to serve
static files rather than having Jifty do it. You will need to manually flatten the static file
structure yourself for this to work, but it can be done.

etc.
Your application configuration may have additional changes that need to be made for your application
to operate properly in a production environment.

Make sure to check over all the settings to make sure they will work in your production environment
to save yourself headaches later.

Deploy the Database

If you've been developing your server using the default SQLite configuration, you will likely want to
change this for your production server. SQLite might work for production environment, but chances are it
will not.

For your production system, you will probably want to modify the "Driver" to suit your production
environment. For example, if you were going to change to use a MySQL server, you might change your
"Database" configuration in etc/site_config.yml to something like this:

Database:
Database: myapp
Driver: mysql
Host: mysql.example.com
Password: 'secret'
RecordBaseClass: Jifty::DBI::Record::Cachable
User: myapp_user
Version: 0.0.1

In this example, the server is running the MySQL driver, connecting to the host at "mysql.example.com"
with the username "myapp_user" and password "secret".

You will need to create the database and grant access to the users according to your RDBMS administrator
documentation. In MySQL, this could be done to match the example above by running these commands:

mysqladmin -uadmin -psecret create myapp
mysql -uadmin -psecret -e "grant all on myapp.\* to myapp_user'@'myapp.example.com identified by 'secret'"

Please refer to your RDBMS documentation for full details on how to configure your database.

Configure the Web Server

There are several ways to configure your web server. You can use FastCGI or mod_perl or you can use a
proxy to the Jifty simple server. The first two options are what you will most likely want to do, but the
proxy configuration is presented for completeness.

Configuring FastCGI

Several configurations are explained by the "fastcgi" in Jifty::Script::FastCGI script that comes with
Jifty. It is recommended that you take one of those and modify the configuration to suit your needs.

It may take a few tries to get the configuration exactly right. Be sure to check the server logs for your
web server when looking for problems.

Configuring mod_perl

Support for mod_perl version 2.0 is provided by Jifty::Script::ModPerl2. Remember that you need to
completely stop and start the Apache server after the Perl modules in your application are changed.

Configuring a Proxy

You can use a proxy with the built-in server. This can be done with the following configuration in
Apache:

<Location />
ProxyPass / http://localhost:8888/
ProxyPassReverse / http://localhost:8888/
</Location>

Place that declaration in your main configuration or virtual host configuration file and then whenever
you run:

bin/jifty server

Apache will proxy your server on port 80 for you. This may not work exactly as expected because the
built-in server is intended for testing, not for a production environment. As such, it is not well-tested
as a production server.

Configure File Permissions

The <var/> subdirectory in your application should be writable by the server process. If it runs as non-
root UID (for example, FastCGI and Apache processes are usually running under the user named apache or
www or something alike), you need to change the group or user permissions for this directory.

For example, assume your application will run under user apache and group apache. Then the following
commands should do the job:

chgrp -R apache var
chmod -R g+w var

A more flexible way would be to create a new group myapp and add apache user in it. This allows you to
maintain the application from non-root login and use "sudo" for restarting Apache.

All Systems Go

Once you have done all of the above, your application should be ready to use at the production address
you have configured.

Updating the Production Server
After you've made some collection of updates to your Jifty application, you'll then need to install those
changes onto your server and prepare your application to use the changes.

This documentation assumes a "cold" upgrade with the application offline during the duration of the
process. A future version of this document might also include instructions for performing a "hot" upgrade
without taking the server offline.

You can do this with the following steps:

1. Shutdown the application.

2. Update the Jifty installation.

3. Update your Jifty application.

4. Merge in configuration changes.

5. Clean up any temporary and cached files.

6. Upgrade your database.

7. Start using the updated application.

Shutdown the Application

This process cannot be performed on a live server. If it is, bad things may happen. You may choose to
shutdown the application in one of two ways: turn off your web server or reconfigure your web server into
an offline mode.

Remember, shutdown all Jifty application processes before continuing, or bad things may happen!

Shutting Down the Server

This will involve a two step process. First, you will want to shutdown your web server. The second is to
shutdown the Jifty server. If you are using the built-in Jifty server, you may do this by running:

bin/jifty server --stop

If you are using FastCGI, you will need to locate your server's process IDs and then kill all the
processes. If this is the only FastCGI and Perl script running on your system, you may be able to just
run:

killall perl

However, that might stop too many processes in many environments, so you'll just have to find the
processes and clean them up as suits your server.

Offline Mode

If you want to provide you site visitors with some feedback letting them know that the web site is down,
you might want to provide an alternative configuration for your application. You still need to stop all
your Jifty application processes when you engage the offline configuration.

For example, you could have the following configuration on an Apache server to run an offline mode:

<Location />
RewriteEngine on
RewriteRule ^.*$ /offline.html
</Location>

Then create a file named "offline.html" in your server root containing the message you wish to give your
visitors.

You can make this configuration change and then restart your web server to give it effect. Then, stop all
the Jifty application processes.

Update Jifty

This is exactly the same as "Install Jifty" above. Again, you'll probably want to install the same
version as you are using to developing with. If you have not made any changes to the Jifty version you
are using, you may skip this step.

Update the Application

This is again similar to what you've done above. You just need to update all the files that have changed.
However, you should be careful not to clobber any configuration changes that you need to remember.

If you've used the suggestion of using a branch described above, you can automatically update your
production server to use the latest code without risk of clobbering your changes on the production
server.

In Subversion, you will first need to recall the revision of either the initial copy or of the last merge
you performed. If you stored this information in the log message, you can retrieve it by running:

svn log http://svn.example.com/myapp/branches/production

When you have the revision number, you can then merge in all the latest changes in your production server
copy. Here, I assume that the revision number is "1234".

cd myapp
svn merge -r 1234:HEAD http://svn.example.com/myapp/trunk .

If you're using SVK, you can just run the following:

cd myapp
svk smerge //myapp/trunk .

SVK automatically remembers the revision number for you so you don't have to worry about it.

Next, watch for any conflicts that might have occurred and be sure to correct them. Check over all the
changed files and make sure they look alright and you should also run your tests again to be sure
everything is working. Once you're sure everything is correct, you can accept the changes with:

svn commit

or:

svk commit

Your code should now be ready.

Configuration Changes

Again, you need to look for any configuration updates that need to adjusted. This is no different from
the process during the initial installation.

Clear Temporary/Cached Files

This step is important to prevent strange issues from occurring. You remove all files from the following
directories:

• var/mason/cache

• var/mason/obj

You can run the following command (BE CAREFUL TO TYPE THIS CORRECTLY OR PAY THE CONSEQUENCES):

rm -rf var/mason/{cache,obj}/*

This means that your application will have to rebuild these cached files, which will slow your
application down slightly at first.

However, if these files are left in place, the Mason server may continue using cached versions of files
that don't match your latest updates. This will lead to very strange problems.

Upgrade the Database

If you've made any changes to the database schema or to the structure of your data that requires an
upgrade, you will need to run:

bin/jifty schema --setup

See Jifty::Manual::Upgrading.

All Systems Go

Now that all these changes have been made, you are ready to start your web server or reconfigure your web
server for production mode and restart.

NAME

DESCRIPTION

HOW TO

SEE ALSO