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Eric.London's picture

Sometimes there's no escaping hard coded hostnames being stored in your Drupal database. If you have ever setup language translations (i18n) in production, and then deployed the site to a development environment (with a different hostname), you'll know exactly what I am talking about. The first thing you'll notice in your dev site is that all your urls are linking back to the production site, and you may even have a hard time logging in.

If you query the languages table, you'll see the following:

select language, domain
from {languages}

Results:

language	domain
de		http://de.ericlondon.com
en		http://www.ericlondon.com
es		http://es.ericlondon.com
fr		http://fr.ericlondon.com

At first I thought it would make sense to write a module or a hook_update_n() function to resolve this problem when deploying to another environment, but this method seemed rather clunky, repeatedly running the same revision of a module's update script. In the end, I decided to simply write a PHP script to run via Drush. The following code fetches your default language and all records in the language table, loops through them, and updates the hostname records to match your new hostname...

<?php
// ensure this script is being called from Drush ONLY
// ensure HTTP_HOST is being used
if (
  !
is_array($_SERVER['argv'])
  ||
substr($_SERVER['argv'][0], -9) != 'drush.php'
 
|| substr($_SERVER['SCRIPT_FILENAME'], -9) != 'drush.php'
 
|| !strlen($_SERVER['HTTP_HOST'])
) {
 
header('HTTP/1.1 403 Forbidden');
  die(
'Access Denied.');
}

$output = "";

// fetch hostname from globals
$http_host = $_SERVER['HTTP_HOST'];

// ensure http host exists
if (!$http_host || !is_string($http_host)) {
  die(
'Error occurred fetching http host.');
}

// set default http host
$default_http_host = 'www.' . $http_host;

// define default language
$default_language = 'en';

// define SQL to fetch default language
$sql = "
  select *
  from {languages}
  where language = '%s'
"
;

// execute SQL
$default_language_record = db_fetch_object(db_query($sql, $default_language));

// ensure record exists
if (!is_object($default_language_record)) {
  die(
'Error occurred fetching default language.');
}

// update default language record
$default_language_record->domain = 'http://' . $default_http_host;

// set new variable for "language_default"
variable_set('language_default', $default_language_record);
$output .= "Setting language_default variable to: " . $default_language_record->domain . "\n";

// fetch language records
$sql = "
  select *
  from {languages}
"
;
$resource = db_query($sql);
$language_records = array();
while (
$row = db_fetch_object($resource)) {
 
$language_records[] = $row;
}

// correct language records
foreach ($language_records as $key => $value) {

 
// determine language prefix 
 
switch ($value->language) {
    case
$default_language:
     
$prefix = 'www.';
      break;
    default:
     
$prefix = $value->language . '.';
      break;
  }

 
$new_domain = 'http://' . $prefix . $http_host;

 
$sql = "
    update {languages}
    set domain = '%s'
    where language = '%s'
  "
;
 
db_query($sql, $new_domain, $value->language);

 
$output .= "Setting language record for language: \"" . $value->language . "\" to: " . $new_domain . "\n";

}

drupal_flush_all_caches();

$output .= "Executed: drupal_flush_all_caches()\n";

$output .= "DONE.\n";

echo
$output;
?>

I dropped this script (named: fix_env.php) in the root of my Drupal site, and then executed it via Drush using the following shell command:

drush --uri=http://tdb.erl.dev scr fix_env.php

The "--uri" flag allows you to specific a hostname for multi-site environments, and the "scr" flag allows you to specify a php script to execute.

NOTE: I'm in the habit of never using sites/default, because it's a real PITA if you ever try to move your site into a multi-site configuration ^_^

After running the script via Drush, my hostname database records have been corrected to match my development environment...

select language, domain
from {languages}

Results:

language	domain
de		http://de.tdb.erl.dev
en		http://tdb.erl.dev
es		http://es.tdb.erl.dev
fr		http://fr.tdb.erl.dev

There are some great development modules for Drupal (Devel, Coder, Reroute_Email, Demo, etc), but you probably don't want to have them enabled in a production environment. Deployments to production can be simplified by adding a hook_update_N function in your module's .install file. In this function you can take care of administrative functions such as importing views and CCK node type definitions (essentially, anything exportable). In this quick code snippet, I'll show how you can create a module update function to disable your development modules on update.

<?php
// NOTE: see the documentation on hook_update_N for version naming conventions
function MYMODULE_update_6100() {
 
 
// check for production environment hostname
 
if ($_SERVER['HTTP_HOST'] == 'your-production-hostname') {
   
   
// rebuild the module cache
   
module_rebuild_cache();
   
   
// define a list of development modules to disable
   
$modules_disable = array(
     
'reroute_email',
     
'coder',
     
'demo',
     
'performance',
     
'devel_node_access',
     
'devel_generate',
     
'devel_themer',
     
'devel',
    );
   
   
// disable modules
   
module_disable($modules_disable);

  }

}
?>

Now that your module update function is created, you can deploy your file updates to production (preferably using subversion) and run the update.php script, apply your module update, and disable your development modules.

It's important to treat content management systems like any other application and segment development, test, and production. Before adding content and attaching files to nodes, it's very important to set the file system path correctly and establish a deployment procedure.

One way to make the transition from development to production a smooth process is to use the same directory for your files. If you are using one Drupal installation for each project sites/default/files will work fine. If you set your file system path specific to your development hostname (for example: site/dev.HOSTNAME.com/files), you'll be in trouble when you transition to a new hostname.

Here's an example process to show how you could transition a site from development to test (or any other environment).

1. Migrate your MySQL database to the new server. Each environment should use its own database.

# connect to mysql as a privileged user to create a new database and user
$ mysql -u USER -pPASSWORD -h NEWSERVERHOST
> create database NEWDATABASE;
> GRANT ALL PRIVILEGES ON NEWDATABASE.* TO 'NEWUSER'@'localhost' IDENTIFIED BY 'NEWPASSWORD';
> exit;

# backup database
$ mysqldump -u USER -pPASSWORD DATABASE > DATABASE.sql

# import database
$ mysql -u NEWUSER -pNEWPASSWORD -h NEWSERVERHOST NEWDATABASE < DATABASE.sql

2. Copy your Drupal installation to the new server. Hopefully, you're using subversion (or some other version control software) to deploy these files.

3. Create a new folder in your sites directory for the new hostname. Copy your existing settings.php into the new folder. Edit this file and update the MySQL connection string to match your new database, user, and password.

4. Create a new Apache virtual host for your new hostname and direct DNS accordingly.

Now, if DNS has been setup for your new hostname, the site should be up and running on the new server with a new hostname.

Additional thoughts: It's very important to avoid hard coding hostnames and absolute paths in your links, code, and themes. I promise, it will make your deployment process a nightmare.

I do all of my development on a Parallels virtual machine 1) to keep my host operating system stable at all times; and 2) so I can run the same operating system as our production servers (to reduce the differences in configuration & chance of a deployment issue). I'm a fan of RPM based operating systems (vs APT) so I prefer Centos. To improve performance I do not run a GUI (KDE, Gnome, etc) and I install the bare minimum set of packages. My linux server philosophy has always been: if you don't use it or don't know what it does, don't install it; and if you don't know it does, Google it. My preferred IDE is Eclipse, so I install that on my host operating system (OSX). So how do I edit my files on my virtual machine? Samba. Here's how I setup a basic samba configuration:

Install Samba (as necessary)

sudo yum install samba

Create a backup of the original samba configuration file, just in case

sudo cp /etc/samba/smb.conf /etc/samba/smb.conf.orig

Here's a basic smb.conf file I use with a description for each config setting:

[global]
    # workgroup should match your network that your host operating system is on
    workgroup = MYWORKGROUP
    # server string is description of samba server
    server string = MY CENTOS VM
    # default security level
    security = user
    # performance tuning
    socket options - TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192
[homes]
    # share comment for user's home directories
    comment = Home Directories
    # hides shares to users without permission
    browseable = no
    # allows privileged users to modify files
    writable = yes
[Vhosts]
    # I share my entire vhosts folder
    comment = Vhosts
    # to be more secure, I only allow my primary user from my host operating system access
    valid users = eric
    # allows privileged users to modify files
    writeable = yes
    # this is the path to my Apache vhosts
    path = /var/www/vhosts
    # setting a umask will ensure permissions will be set correctly on files created across a samba share
    directory mask = 775
    create mask = 664

Create a samba user that matches your host operating system

sudo smbpasswd -a eric

Restart Samba

sudo /etc/init.d/smb restart

Now, from your host operating you can connect to your vhosts share and edit your files. From OSX, I use the "connect to server" command in the finder menu and specify the IP address of my virtual machine. The samba share will now be mounted in /Volumes/IPOFYOURVM. When I create a new project in Eclipse, I uncheck the default location and choose to create the project on my virtual machine. tah-dah

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