The def_file is the provisioning document used to add a component or host to the implementation.

You can use a larger provisioning file for this purpose, or you can use one that specifies exactly one component or host. If you choose to use a larger provisioning file, then you must specify which component or host listed within it that you are adding.

For example, say you want to add a host called new_host to your application. You could add provisioning information for new_host to your existing provisioning file, myApp.xml. When you run the add-host command, you would give it the host name as well as the provisioning file name.

In the case of scripts, you have two options: you can use a def_file, as you do with components and hosts, or you can provide the necessary information individually, through the --cmd (command), --wd (working directory), and --log-file settings.