There are various instances where we moght want to
jail a user to a specific directory. One such scenario is where in we want to create a secure FTP user clark who should only have secure FTP or secure cp access to the directory
/home/sftp-clark. To achieve this we use an open source tool 'jailkit'. The latest stable version of this tool (as of this writing) can be downloaded from: http://olivier.sessink.nl/jailkit/jailkit-2.13.tar.bz2.
Now let's create a promise file that downloads the tool, installs it on a number of servers and then creates a `jailed` user as discussed above. As 'jailkit' is not a standard package available in all OS repositories, we will not use the standard CFEngine 'package' ...