Graphical Installers

Graphical Installers are ubiquitous in the Windows world: programs that install the real program according to the input of the user.

Features

• A graphical installer, usually walking the user through a series of dialogs
• The user is given choices such as where they want the application, what features do they want installed, which of the common file types do they want to have taken over.
• An uninstaller application is usually included for removing the program.

Advantages

• Provides a graphical progress indicator of a long install.
• Allows install-time choice of aspects of the installation.
• The executable usually has the ability to execute arbitrary code, and so perform advanced operations at install time. On Windows, they usually perform all of the installation operations themselves, occasionally notifying the OS of an action that they have taken.,
• Provides an opportunity to display terms and conditions/software licenses.

Disadvantages

• In Windows, can usually only be installed by someone with Administrator privileges. Vista has reduced this need, somewhat.
• The ability of installers to perform arbitrary operations makes auditing their changes very difficult, and hence rollback/uninstallation is unreliable.
• A lot of end users don't need all the options; they can only be confusing.
• Its very hard to automate the installation of other people's graphically-installed applications.
• Its very hard to automate the uninstallation of other people's graphically-installed applications.
• If the uninstaller gets deleted, it is very hard to complete uninstall the application.
• Increased internationalisation costs: the installer needs to be customised for every target language.

Graphical installers are ubiquitous in Windows; every application comes with one. These may be MSI Installers, or they may be completely home-written. However they are implemented, the fact that all installation actions are not managed by the OS themselves, combined with the general need for the individual installing the software to have Administrator privileges, means that installations can damage the state of the system. In our experience, it is installing and uninstalling windows applications that leaves windows systems in a mess, a mess from which a rebuilt system is the sole solution.

At the same time, users from the windows ecosystem expect them. The transition to an RPM- or deb - managed system is unexpected. Some projects, such as Autopackage try and provide some of the classic experience, albeit within the context of a partially managed installation.

SmartFrog support

We do provide a graphical installer for anyone who wants full control of how to install the tool. This installer is built with IzPack; there is a command line option for anyone who wants to hide the GUI. We do not expect the SmartFrog agents to be installed on farms of machines this way; pushing out the [SmartFrog RPM] into the base OS image is the best way.

We have deployed applications that only support GUI installers; a classic is Oracle, which historically has required an X11 server on the target machine, as even its command-line mode attempts to create windows. We much prefer applications which have a command line, and those which can be used without needing a root/administrator account to do any installation at all.