| Title: Image Capture Sequence |
| |
| ## Modularization Example |
| |
| The following diagram shows how the image capture sequence |
| differs if different provisioning modules are used -- xCAT and |
| VMWare. |
| |
| Take note of the following: |
| |
| * The calls made by image.pm to the xCAT and VMWare capture() |
| subroutines are **identical**. The image.pm state module does not |
| care which provisioning engine is being used. All it knows is that a |
| provisioning engine object has been created before image.pm::process() was |
| called, the object can be accessed via $self->provisioner, and the |
| name of the subroutine to call is capture(). |
| * The calls made by xCAT and VMWare's capture() subroutine to the |
| Windows.pm pre_capture() subroutine are **identical**. All a |
| provisioning engine module needs to know is that an OS object has been |
| created, the object can be accessed via $self->os, and the name of the |
| subroutine to call is pre_capture(). |
| * Provisioning engine modules do not not need to know any of the operating |
| system details. They assume the OS module's pre_capture() |
| subroutine will perform all the steps necessary for the particular OS to be |
| captured and that the computer will be shut down (or left in the state |
| specified by the end_state argument) when pre_capture() returns. |
| * The OS module's pre_capture() subroutine does not care which |
| provisioning engine is being used. The steps it performs are |
| identical. |
| * A very similar example could be made using the same provisioning engine |
| module and different OS modules. |
| |
| <img src="image_capture_sequence_xcat.png"> |
