Duplicate Installation

Contents

Introduction
Copy Elgg Code to the Test Server
Copy Data to the Test Server
Edit settings.php
Copy Elgg Database
Database Entries
- Change the installation path
- Change the data directory
Check .htaccess
Update Webserver Config
Run upgrade.php
Tips
Related

Introduction 

Why Duplicate an Elgg Installation?

There are many reasons you may want to duplicate an Elgg installation: moving the site to another server, creating a test or development server, and creating functional backups are the most common. To create a successful duplicate of an Elgg site, 3 things need to be copied:

Database
Data from the data directory
Code

Also at least 5 pieces of information must be changed from the copied installation:

elgg-config/settings.php file which could also be in the pre 2.0 location engine/settings.php
.htaccess file (Apache) or Nginx configuration depending on server used
database entry for your site entity
database entry for the installation path
database entry for the data path

What Is Not Covered in This Tutorial 

This tutorial expects a basic knowledge of Apache, MySQL, and Linux commands. As such, a few things will not be covered in this tutorial. These include:

How to backup and restore MySQL databases
How to configure Apache to work with Elgg
How to transfer files to and from your production server

Before You Start 

Before you start, make sure the Elgg installation you want to duplicate is fully functional. You will also need the following items:

A backup of the live Elgg database
A place to copy the live database
A server suitable for installing duplicate Elgg site
(This can be the same server as your production Elgg installation.)

Backups of the database can be obtained various ways, including phpMyAdmin, the MySQL official GUI, and the command line. Talk to your host for information on how to backup and restore databases or use Google to find information on this.

During this tutorial, we will make these assumptions about the production Elgg site:

The URL is http://www.myelgg.org/
The installation path is /var/www/elgg/
The data directory is /var/data/elgg/
The database host is localhost
The database name is production_elgg
The database user is db_user
The database password is db_password
The database prefix is elgg

At the end of the tutorial, our test Elgg installation details will be:

The URL is http://test.myelgg.org/
The installation path is /var/www/elgg_test/
The data directory is /var/data/elgg_test/
The database host is localhost
The database name is test_elgg
The database user is db_user
The database password is db_password
The database prefix is elgg

Copy Elgg Code to the Test Server 

The very first step is to duplicate the production Elgg code. In our example, this is as simple as copying /var/www/elgg/ to /var/www/elgg_test/.

cp -a /var/www/elgg/ /var/www/elgg_test/

Copy Data to the Test Server 

In this example, this is as simple as copying /var/data/elgg/ to /var/data/elgg_test/.

cp -a /var/data/elgg/ /var/data/elgg_test/

If you don’t have shell access to your server and have to ftp the data, you may need to change ownership and permissions on the files.

Note

You also need to delete cache directories from your disk. These correspond to cacheroot and assetroot directories in your config.

Edit settings.php 

The elgg-config/settings.php file contains the database configuration details. These need to be adjusted for your new test Elgg installation. In our example, we’ll look in /var/www/elgg_test/elgg-config/settings.php and find the lines that look like this:

// Database username
$CONFIG->dbuser = 'db_user';

// Database password
$CONFIG->dbpass = 'db_password';

// Database name
$CONFIG->dbname = 'elgg_production';

// Database server
// (For most configurations, you can leave this as 'localhost')
$CONFIG->dbhost = 'localhost';
// (For most configurations, you can leave this as 3306)
$CONFIG->dbport = 3306;

// Database table prefix
// If you're sharing a database with other applications, you will want to use this
// to differentiate Elgg's tables.
$CONFIG->dbprefix = 'elgg';

We need to change these lines to match our new installation:

// Database username
$CONFIG->dbuser = 'db_user';

// Database password
$CONFIG->dbpass = 'db_password';

// Database name
$CONFIG->dbname = 'elgg_test';

// Database server
// (For most configurations, you can leave this as 'localhost')
$CONFIG->dbhost = 'localhost';
// (For most configurations, you can leave this as 3306)
$CONFIG->dbport = 3306;

// Database table prefix
// If you're sharing a database with other applications, you will want to use this
// to differentiate Elgg's tables.
$CONFIG->dbprefix = 'elgg';

$CONFIG->wwwroot = 'http://your.website.com/'

Note

Notice the $CONFIG->dbname has changed to reflect our new database.

Copy Elgg Database 

Now the database must be copied from elgg_production to elgg_test. See your favorite MySQL manager’s documentation for how to make a duplicate database. You will generally export the current database tables to a file, create the new database, and then import the tables that you previously exported.

You have two options on updating the values in the database. You could change the values in the export file or you could import the file and change the values with database queries. One advantage of modifying the dump file is that you can also change links that people have created to content within your site. For example, if people have bookmarked pages using the bookmark plugin, the bookmarks will point to the old site unless your update their URLs.

Database Entries 

We must now change 4 entries in the database. This is easily accomplished with 4 simple SQL commands:

Change the installation path 

UPDATE `elgg_config` SET `value` = REPLACE(`value`, "/var/www/elgg_production/", "/var/www/elgg_test/") WHERE `name` = "path";

Change the data directory 

UPDATE `elgg_config` SET `value` = REPLACE(`value`, "/var/data/elgg_production/", "/var/data/elgg_test/") WHERE `name` = "dataroot";

Check .htaccess 

If you have made changes to .htaccess that modify any paths, make sure you update them in the test installation.

Update Webserver Config 

For this example, you must edit the Apache config to enable a subdomain with a document root of /var/www/elgg_test/. If you plan to install into a subdirectory of your document root, this step is unnecessary.

If you’re using Nginx, you need to update server config to match new paths based on install/config/nginx.dist.

Run upgrade.php 

To regenerate cached data, make sure to run http://test.myelgg.org/upgrade.php

Tips 

It is a good idea to keep a test server around to experiment with installing new mods and doing development work. If you automate restorations to the elgg_test database, changing the $CONFIG values and adding the follow lines to the end of the elgg_test/elgg-config/settings.php file will allow seamless re-writing of the MySQL database entries.

$con = mysql_connect($CONFIG->dbhost, $CONFIG->dbuser, $CONFIG->dbpass);
mysql_select_db($CONFIG->dbname, $con);

$sql = "UPDATE {$CONFIG->dbprefix}config
   SET value = REPLACE(`value`, "/var/www/elgg_production/", "/var/www/elgg_test/")
   WHERE name = 'path'";
mysql_query($sql);
print mysql_error();

$sql = "UPDATE {$CONFIG->dbprefix}config
   SET value = REPLACE(`value`, "/var/data/elgg_production/", "/var/data/elgg_test/")
   WHERE name = 'dataroot'";
mysql_query($sql);
print mysql_error();