Migrating a WordPress Website to a New or Different URL / Domain Name

When migrating a WordPress website from one URL to another, it's not as simple as exporting the current database to a SQL file, changing the URLs in the SQL file, dropping all tables in the database, and then re-importing the updated SQL file (which contains the updated URL).  Using a find and replace text editor utility to update the old URL to the new one in the MySQL database dump file IS NOT the right way to do it.

Because of how PHP serializes data, which is then stored in the WordPress database, one cannot simply do a find and replace to update the old URL to the new one.  While it will work for the most part, if you have an option table setting that has been serialized and contains the old URL, you will need to deserialize it first and then reserialize it after updating the values.  You can use WordPress' built-in functions in your theme's functions.php file to do that.  Here is an example of what I had to do in my theme's functions.php

$option = get_option('mytheme_option_name');
$option['logo'] = '{NEWURL}/logo.png';
$option['logo_hd'] = '{NEWURL}/logo@2x.png';
$option['favicon'] = '{NEWURL}favicon.png';
update_option( 'mytheme_option_name', $option );

The easiest way to get an existing WordPress site to run on a new URL or domain name is to use the WP-CLI utility.  Unfortunately, this wasn't going to work for me since I was running an old WordPress website on an old server running PHP 5.5.x.  As a result, I had to manually identify the options that needed to be updated and update them in a way that properly deserialized and then serialized the changes properly.

If you are able to run the WP-CLI utility, here is how you can update / change the URL of the existing website to the new one easily and properly.  Be sure to make a full backup of your existing WordPress database using a utility like PHPMyAdmin or via the command line.  Then, use the below commands (update the values from the example first before running them):

wp option update siteurl 'https://yournewdomain.com'
wp option update home 'https://yournewdomain.com'
wp search-replace 'old-url.com' 'new-url.com'

That should do it.

Running and Debugging Specific WordPress Cron Hooks Manually Using WP-CLI

If your WordPress instance is configured with debugging turned off (WP_DEBUG set to false in wp-config.php) and you need to troubleshoot, debug, or run a specific WordPress cron hook or function manually, you'll find that it's pretty tough to do so.  Fortunately, I found a relatively easy way to do exactly this using WP-CLI.

Install WP-CLI

Install WP-CLI by using the below commands as root:

sudo -i
curl -O https://raw.githubusercontent.com/wp-cli/builds/gh-pages/phar/wp-cli.phar
chmod +x wp-cli.phar
sudo mv wp-cli.phar /usr/local/bin/wp

Now, change into your WordPress instance vhosts directory:

cd /var/www/vhosts/{YOUR_DOMAIN}/httpdocs

Update the above path as necessary.

To run all the scheduled WordPress cron events, use this command:

wp cron event run --all --allow-root

To run a specific WordPress cron hook, use this command:

wp cron event run "NAME_OF_CRON_HOOK" --allow-root

If you need help determining the name of the cron job hook you specifically want to run or debug, install the WP Control plugin in your WordPress instance. Then visit the /wp-admin/tools.php?page=crontrol_admin_manage_page page to see a list of cron hooks and when they run.  Grab the name from the "Hook" column and update your wp cli command to run that cron event!

You can add echo statements and other code to your individual cron function plugins to better debug and troubleshoot them.