WordPress login via site preview does not work with Plesk from cloud image

Symptoms

• Log in to WordPress instance via Site Preview link http://203.0.113.2/plesk-site-preview/www.example.com/192.0.2.2/wp-login.php leads to a page timeout error:

  This site can’t be reached
   192.0.2.2 took too long to respond. 
   ... 
   ERR_CONNECTION_TIMED_OUT

• Plesk is installed from a cloud image, for example, Plesk Onyx (BYOL) from AWS Marketplace.

• Plesk is behind NAT. The private IP address is 192.0.2.2 and the public IP address is 203.0.113.2. IP mapping is configured in Tools & Settings > IP addresses

• The Default Quick Preview mode is enabled in Tools & Settings > Website Preview Settings.

• Incorrect site preview link is opening after CMS credentials submitting:

  http://192.0.2.2/plesk-site-preview/www.example.com/192.0.2.2/wp-admin/

  instead of correct one:

  http://203.0.113.2/plesk-site-preview/www.example.com/192.0.2.2/wp-admin/

Cause

This is a Plesk bug with ID PPPM-10371 which is planned to fixed in one of the future product updates.

The outdated configuration for site preview is delivered with Plesk cloud image.

Resolution

Warning: Plesk Preview is not intended to log into the CMS and does not use a secure HTTPS connection. It is strongly recommended not to use it to log into the CMS in order to avoid password sniffing by third-parties.

As a workaround, update the configuration file according to the steps below:

1. Connect to the server via SSH.

2. Backup the current configuration file:

   # cp /etc/sw-cp-server/conf.d/plesk_site_preview.conf{,bak}

3. Download the archive with the new configuration file plesk_site_preview.zip and unpack it with replacement to /etc/sw-cp-server/conf.d/:

   # wget https://plesk.zendesk.com/hc/article_attachments/360031457873/plesk_site_preview.zip
   # unzip plesk_site_preview.zip -d /etc/sw-cp-server/conf.d/

4. Reload the sw-cp-server service to apply the changes:

   # service sw-cp-server reload