Web Applications

The majority of customers purchase web hosting accounts to run different web applications: Webmail, CRM, e-commerce systems, blogs, image galleries and so on. Typically, such users are unable to install the apps by themselves because they lack the necessary technical skills and experience, so they ask their service providers to do it. Hence, the provider's staff becomes overloaded with routine operations related to the apps. To ease the installation (and maintenance) of web apps and reduce the staff's workload, Plesk offers a number of free and commercial apps available to Plesk users directly from their Customer Panel.

There are various factors that regulate what apps are available to your customers. For example, the app list is restricted by service plan or subscription properties, local repository settings and so on. To see how the apps list is formed, refer to the How Apps Become Available to Your Customers section.

App Types

Plesk offers two types of apps:

• Apps that are installed directly on a website (such as the WordPress blogging platform or the Joomla! content management system).
• Apps that do not require a website for their installation. These are usually external apps located somewhere on the web that only provide a link to their services (such as the iMind videoconference service or OfficeDrive - an online office suite).

Apps can be either free or commercial. Commercial apps require providing a license key to start working with them.

App Installation and Maintenance

The process of installation does not require any specific skills from customers. They fill in app settings (for example, administrator credentials), and Plesk installs the app for them. Subsequent app management is also facilitated as apps are updated or removed directly in Plesk. Moreover, customers can access some functions that apps make available in the Customer Panel (without the need to log in to an app). For example, customers can upload a new WordPress theme or add a SugarCRM user account directly from their Customer Panel. Such app functionality is a service the app provides to customers.

Apps Backup and Restoration

Apps are backed up by standard Plesk means (the backup utility). Since the backup unit is a subscription, all apps in a subscription must be backed up at once. The apps from a backup are restored along with other subscription data.

Application Vault and Application Catalog

If there are no restrictions on app availability, the list of available apps in the Customer Panel includes all apps from the following two sources:

1. Application Catalog - the remote repository held by Plesk, the main source of apps.
2. Application Vault - a local repository in Plesk. Each Plesk has its own Application Vault that is available through the Server Administration Panel (Server Management > Tools & Settings > Application Vault).

The main purposes of the Application Vault are to:

• Extend the list of available apps by uploading your own APS packages.
  This is relevant if you want to offer some apps to your customers but these apps are not listed in the Application Catalog.
• Apply updates to apps installed from the Application Catalog.
• Gain control over apps from the Application Catalog.
  Download an app from the Catalog to the Vault to control some of its options. For example, you can toggle its visibility to customers or configure its server-wide settings.

For more information on managing apps through the Application Vault, refer to the Application Vault section.

Summing up, the Application Vault is not only a local repository of apps but a tool to control versioning, visibility, and server-wide settings of apps from the Application Catalog. For better understanding of the Application Vault, refer to the scheme shown in the How Apps Become Available to Your Customers section.

Sharing Apps among Plesk Servers

Adding an APS package to the Application Vault will make it available only to your customers. If you wish to share your app with users of other Plesk servers, add an app to the Application Catalog. The Catalog accepts only apps packaged according to Application Packaging Standard (APS) - the set of rules that allows easy app installation and management. After you have packaged your app, it must pass the certification procedure. For details on how to do this, see http://apsstandard.org/learn.