Unable to access Plesk Installer web interface on Amazon EC2 or Google Cloud instance without root password

Symptoms

Unable to access Plesk Installer web interface without having the root password on Amazon EC2 or Google Cloud instance:

Cause

Due to security restrictions on Amazon EC2 or Google Cloud instances, the command sudo is used for obtaining root privileges.

The password for the user root is not set by default.

Resolution

1. Connect to the server using SSH key (see also the corresponding articles from AWS and Google Cloud: 1, 2).

2. Obtain root privileges:

   ubuntu@192.0.2.2:~$ sudo -i

3. Change root password:

   root@192.0.2.2:/home/ubuntu# passwd root

4. Log into Plesk.

5. Access Plesk Installer in Tools & Settings > Updates & Upgrades.

6. Input the newly updated password for the user root and follow the appearing instructions to use Plesk Installer functionality.