vSphere SDK for Perl Programming Guide - Documentation - VMware

vSphere SDK for Perl Programming Guide
The Vim::find_entity_views() subroutine uses the value the user passes in later in the script. The value
must be one of the managed‐entity types listed as view_type parameter supported by
Vim::find_entity_views().
NOTE Your script must call Opts::parse() and Opts::validate() to process the options available for all
scripts, even if you do not define script‐specific command‐line options.
When you attempt to run a script and do not supply all necessary options, the vSphere SDK for Perl displays
usage help for the script, as in the following example:
perl simpleclient.pl
Required command option 'entity' not specified
Common VI options:
. . .
Command-specific options:
--entity (required)
ManagedEntity type: ClusterComputeResource, ComputeResource, Datacenter,
Folder, HostSystem, ResourcePool, VirtualMachine...
Step 3: Connect to the Server
The vSphere API is hosted as a secure Web service on a vCenter Server and ESX/ESXi system. By default, the
Web service is available over HTTPS. Clients must provide valid credentials to connect to the service.
Depending on the specifics of your server, you might have to enter only a user name and password. You might
need other information. See Table 1‐3, “Options Available for all vSphere SDK for Perl Scripts,” on page 15.
A call to Util::connect() connects to the server.
When a script reaches the call to Util::connect(), the vSphere SDK for Perl runtime checks the environment
variables, configuration file contents, and command‐line entries (in this order) for connection options. If the
options are not defined, the runtime uses the defaults (localhost and no user name and password) to set up
the connection.
Step 4: Obtain View Objects of Server-Side Managed Objects
When you call the subroutines in the Vim package to retrieve entities from the host, the vSphere SDK for Perl
runtime creates the corresponding Perl objects (view objects) locally.
Example 2‐1 uses the Opts::get_option() subroutine to assign to $entity_type the string value of the
parameter that the user passes in when executing the script. Example 2‐1 then uses $entity_type as the
view_type parameter in the subsequent call to Vim::find_entity_views().
# get all inventory objects of the specified type
my $entity_type = Opts::get_option('entity');
my $entity_views = Vim::find_entity_views(view_type => $entity_type);
The Vim::find_entity_views() subroutine creates a local Perl object (an array of references) from the
server‐side managed object of the specified entity type.
IMPORTANT This object is static and must be explicitly updated when the corresponding server‐side object
changes.
Step 5: Process Views and Report Results
The last part of the script processes the views. For this step, you must know the view objects’ properties and
methods, so you must understand the server‐side objects. See “Understanding Server‐Side Objects” on page 24
for an introduction. For in‐depth information about server‐side objects, see the vSphere API Reference Guide
which is included on the vSphere SDK for Perl documentation page.
Because views are Perl objects, you use Perl object‐oriented syntax to process the views. Example 2‐1 loops
through the array of entities returned (@$entity_views) and accesses the name property of each entity by
calling $entity_view->name. The example then prints the name of each entity to the console.
22 VMware, Inc.