How to install and configure the Plesk Extension Manager

You will learn how to install and configure the Plesk Extension Manager to manage third-party modules on your server. These steps target Plesk Obsidian 18.x running on Linux distributions like Ubuntu or AlmaLinux. The process involves enabling the service, adding repository sources, and verifying that the extension manager is active.

Prerequisites

• Plesk Obsidian 18.x or later installed on the server.
• Root or administrator access to the Plesk control panel.
• Internet connection to download extension packages.
• At least 200 MB of free disk space for extension storage.

Step 1: Access the Plesk Control Panel

Open your web browser and navigate to the IP address or domain name where Plesk is hosted. Log in with your administrator credentials. You will see the main dashboard with the list of available services. Locate the Tools & Settings section in the left-hand menu.

Step 2: Open the Extension Manager

Click on Extension Manager under the Tools & Settings menu. This opens the interface for managing third-party modules. You will see a list of installed extensions and a search bar at the top. If the interface loads but shows no extensions, the service might be disabled.

Step 3: Enable the Extension Manager Service

Ensure the Extension Manager service is running. In the Plesk interface, look for a toggle switch or a status indicator labeled Extension Manager. If it is grayed out, click it to enable the service. The status should change to green or show Running. This allows the system to download and install new modules.

Step 4: Add Extension Repositories

By default, Plesk includes a built-in repository for official extensions. To add third-party repositories, click the Add repository button. Enter the URL provided by the extension vendor. For example, use the official repository URL for a specific tool. Click Save to add the source. You will see the new repository appear in the list below.

Step 5: Configure Repository Settings

Click on the newly added repository to edit its settings. Check the box labeled Enable to allow package downloads from this source. Set the Priority field to a low number if you want to override default packages. Click Save to apply the changes. The system will now fetch updates from this new source.

Step 6: Update the Extension List

Refresh the list of available extensions. Click the Refresh button or reload the page. You will see a list of available modules from the repositories you added. Scroll down to see the full list. If the list is empty, check your internet connection and repository URLs.

Step 7: Install a Third-Party Extension

Locate the extension you want to install in the list. Click the Install button next to the desired module. Read the description and click Install again to confirm. The system will download the package and configure it automatically. You will see a progress bar indicating the installation status.

Step 8: Verify the Extension Installation

Check the status of the newly installed extension. Look for the Installed badge next to the module name. Click Details to view the version number and configuration options. If the module is missing, repeat the installation step. The extension should now appear in the main list.

Verify the installation

Run the following command in the terminal to check the status of the Plesk Extension Manager service:

systemctl status plesk-extension-manager

You will see active (running) in the output. If the service is inactive, start it with:

systemctl start plesk-extension-manager

Then reload the Plesk web interface to see the updated list of extensions.

Troubleshooting

Error: Repository connection failed
The system cannot connect to the extension repository. Check your internet connection and verify that the repository URL is correct. Ensure that the server can reach the vendor's servers on port 443. Try pinging the repository host from the server terminal.

Error: Permission denied when installing extension
The installer lacks the necessary privileges to write to the extension directory. Log in as root or use sudo when running commands. Ensure the Plesk user has write permissions to the /var/lib/psa/ directory.

Error: Extension module not found after installation
The module was not registered correctly. Run the following command to rescan the extension list:

psa-cli extension-manager list

If the list is still empty, restart the Plesk server:

systemctl restart plesk

After the restart, refresh the Extension Manager page in the control panel. Check the logs at /var/log/psa/extension_manager.log for detailed error messages. Review the last few lines to identify the specific failure point.