Provisioning Engine Module Interface Specification

Background

• Provisioning module objects are created by State.pm::initialize() when a new state object is created.
• Provisioning module objects are available within state modules and OS modules
• Provisioning module objects are not available within other types of modules for safety.

{color:#6600ff}{}Explain:{color}

• {color:#6600ff}{}define what we mean by “provisioning system”{color}
• {color:#6600ff}{}give examples of provisioning systems{}{color}
• {color:#6600ff}{}could be bare metal, virtual, differentiated, undifferentiated, a service, a special piece of hardware, eventually VCL could provision various types of resources{}{color}
• {color:#6600ff}{}relationships among mgt nodes, computers, provisioning systems (such as computer is assigned 1 prov system at a time){color}
• {color:#6600ff}{}computer.provisioningid{}{color}
• {color:#6600ff}{}provisioning table{}{color}
• {color:#6600ff}{}future: management node to provisioning mapping{}{color}
• {color:#6600ff}{}provisioning module implementation is responsible for knowing which OS interactions are necessary{}{color} ** {color:#6600ff}{}image.pm calls provisioner->capture, new.pm calls provisioner->load, it calls OS subs as necessary{}{color}

Provisioning Module Subroutines

It is highly recommended that all provisioning modules implement the following subroutines.  There may be many additional subroutines implemented within a provisioning module.  These will not be called by any of the core VCL modules.

• #node_status
• #capture
• #load
• #power_off
• #power_on
• #power_reset
• #get_current_image
• #get_image_size

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node_status {anchor:node_status}

• Description ** A provisioning module’s node_status routine checks the current status of the node. Through the module this routine is aware of how to figure out if a node is available and loaded with the correct image or needs to be reloaded. ** It returns a hash reference with various information, the most important being the “status”

  ie for the xcat module: hashref: reference to hash with keys/values {status} => <"READY”,“RELOAD"> {ping} => <0,1> {ssh} => <0,1> {rpower} => <0,1> {nodeset} => <"boot”, “install”, “image”, …> {nodetype} => {currentimage} =>

** The status key/value tells the vcl system the node is ready or needs to be reloaded.

capture {anchor:capture}

• Description ** A provisioning module’s capture() subroutine saves the current state of the resource.   ** For the provisioning of computers, this means saving an image of the contents of the hard drive.  Although current VCL implementations focus on provisioning computers, the capture() subroutine does not necessarily need to save an image of a hard drive.  A provisioning module may be developed to save the configuration of a network service or some other type of resource. ** The capture() subroutine is responsible for calling the OS module’s pre_capture subroutine.  This is not called by the image.pm state module because there may be cases where an OS isn’t applicable. ** The capture() subroutine is responsible for waiting for the entire capture process to complete.
• Expected Beginning State ** An administrator has configured the resource and initiated the capture using the VCL website. ** The resource is on and accessible. ** The information contained in the data object describes the image which does not yet exist and will be captured.
• Expected Ending State ** The entire capture process is complete or else an error occurred. ** The capture() subroutine has waited for an image to be captured.
• Called By ** image.pm::process()
• Arguments & Calling Environment ** Should only be called as an object method of a image.pm state object ($self->capture())  ** No Arguments
• Return Values ** 1 *** Resource was successfully captured. *** image.pm may proceed to update the database tables making the image available to be provisioned. ** 0 *** Resource was not successfully captured. *** An administrator needs to investigate the problem.

load {anchor:load}

• Description ** A provisioning module’s load() subroutine is responsible for provisioning the node. ** This means starting a virtual machine, loading a image to disk, or nothing in the case of the standalone lab machine.
• Expected Beginning State ** …
• Expected Ending State ** …
• Called By ** …
• Arguments & Calling Environment ** Must only be called as an object method of a provisioning object ($provisioner->pre_capture())  ** No Arguments
• Return Values ** 1 *** … ** 0 *** … ** Undefined *** …

power_off {anchor:power_off}

• Description ** A provisioning module’s power_off() subroutine is responsible for powering off or down a node.
• Expected Beginning State ** …
• Expected Ending State ** …
• Called By ** …
• Arguments & Calling Environment ** Must only be called as an object method of a provisioning object ($provisioner->pre_capture())  ** No Arguments
• Return Values ** 1 *** … ** 0 *** … ** Undefined *** …

power_on {anchor:power_on}

• Description ** A provisioning module’s power_on() subroutine is responsible for powering on a node.
• Expected Beginning State ** …
• Expected Ending State ** …
• Called By ** …
• Arguments & Calling Environment ** Must only be called as an object method of a provisioning object ($provisioner->pre_capture())  ** No Arguments
• Return Values ** 1 *** … ** 0 *** … ** Undefined *** …

get_current_image {anchor:get_current_image}

• Description ** A provisioning module’s get_current_image() subroutine is responsible for trying to figure out what image is loaded on the node. By reading currentimage.txt located on the node’s in root’s user directory. This routine can be copied from another module.
• Expected Beginning State ** The node is expected to be online and accessible.
• Called By ** node_status()
• Arguments & Calling Environment ** Must only be called as an object method of a provisioning object ($provisioner->pre_capture())  ** No Arguments
• Return Values ** 1 *** … ** 0 *** … ** Undefined *** …

get_image_size {anchor:get_image_size}

• Description ** A provisioning module’s get_image_size() subroutine is responsible for collected the disk usage of the image within the image library.
• Expected Beginning State ** N/A
• Expected Ending State ** …
• Called By ** …
• Arguments & Calling Environment ** Must only be called as an object method of a provisioning object ($provisioner->pre_capture())  ** No Arguments
• Return Values ** 1 *** … ** 0 *** … ** Undefined *** …