To get the PowerCLI version, either watch as you open the interface or type this command:

$(Get-PowerCLIVersion).Major

The preceding command line will produce an output as follows:

6

Otherwise, you can type:

$(Get-PowerCLIVersion).UserFriendlyVersion

Now, this command will produce an output as follows:

VMware vSphere PowerCLI 6.0 Release 1 build 2548067

As shown, the output can be simple or human readable. Either way works for general examination of the command, but both can be used for different purposes. For example, if there is a need to run a specific command that is only available in version 6, then a query of this command may be ideal to stop the display of an error.

These are the highlights of PowerCLI right from version 1.0.1 (when it was named VI Toolkit) up to the latest version 6.0:

To get PowerCLI, there are a few places to start. Google always brings the browser first to the VMware blog site, which is all right as that usually has the correct download link. However, the link is provided later for all the versions of PowerCLI.

The typical installation of PowerCLI, whether it is 4.0 or 6.0, includes the VIX API (discussed earlier), and newer versions include the Remote Console as well. The remote console provides a remote console to any available VM running in the virtual infrastructure.

The installation shown in the following diagram is PowerCLI Version 6.0 on a Windows Server 2008 R2 platform. Let's follow the installation process:

On older versions, the VIX API is shown in the installer, but is not shown in the newer versions.

The final list of applications from a base Windows 2008 R2 server installation looks like this:

PoSH v2 installs natively and includes all the help files as installed on a system. Version 3 changes that dichotomy in to forcing the user to download or access the help online. On PoSH v3, the Update-Help command should be run to ensure all help files are downloaded on to the system where the scripts will to be written. This helps reduce the file space usage on systems not being used for script development. If help is needed on systems where the Update-Help command has not been run, a Get-Help <command> -online command can open an associated web page with the appropriate command syntax shown.

Once the help files are downloaded, a simple query such as Get-Help Get-VM will produce a limited explanation of the command with the name of the command, synopsis, syntax, description, related links (similar commands), and remarks. The remarks section will remain the same for every help request, as it outlines alternate switches in the getting help section.

For most help requests, the scriptwriter either needs an understanding of the syntax or to see examples of the command in use. Using the –examples switch displays the example code built into the help files directly. So typing Get-Help Get-VM –examples displays the following output:

NAME
    Get-VM

SYNOPSIS
    This cmdlet retrieves the virtual machines on a vCenter Server system.

    -------------- Example 1 --------------

    C:\PS>Get-VM -Name MyVM*

    Retrieves all virtual machines whose names starting with "MyVM".

    -------------- Example 2 --------------

    C:\PS>$myDatastore = Get-Datastore -Name "MyDatastore"
    Get-VM -Datastore $myDatastore

    Retrieves all virtual machines that reside on the specified datastore.

    -------------- Example 3 --------------

    C:\PS>$myDatacenter = Get-Datacenter -Name "MyDatacenter"
    Get-VM -Location $myDatacenter


    Retrieves all virtual machines in the specified datacenter.

    -------------- Example 4 --------------

    C:\PS>$myVDSwitch = Get-VDSwitch -Name "MyVDSwitch"
    Get-VM -DistributedSwitch $myVDSwitch

    Retrieves all virtual machines connected to the specified distributed switch.

Help is an extremely useful portion of the script writing process and for understanding how to get information, but what if the command to be used to get, say, VM information is not known? Running the Get-Help VM command will show every cmdlet available with VM in the name with a brief synopsis of each one.

Another option is to use a search engine to locate an example of the certain task or information needed. For example, searching for "PowerShell get VM guest information" produces a number of results from the Get-VMGuest command to utilizing Get-View, and even discusses some methods to get this information from a Hyper-V server. Where too much information is daunting, understanding the more specific information to be searched for will mean the more relevant information should be returned.

Lastly, never be afraid to ask. VMware communities were built on this premise and some of the best scripters asked questions at one point.

Once the installation is complete, a couple of minor tweaks are both required and recommended. The first required portion of the environment setup is to set the execution policy. The execution policy definition is taken directly from the PoSH help file:

Get-Help About_Execution_Policies

Windows PowerShell execution policies let you determine the conditions under which Windows PowerShell loads configuration files and runs scripts.

You can set an execution policy for the local computer, for the current user, or for a particular session. You can also use a Group Policy setting to set execution policy for computers and users.

Execution policies for the local computer and current user are stored in the registry. You do not need to set execution policies in your Windows PowerShell profile. The execution policy for a particular session is stored only in memory and is lost when the session is closed.

The execution policy is not a security system that restricts user actions. For example, users can easily circumvent a policy by typing the script contents at the command line when they cannot run a script. Instead, the execution policy helps users to set basic rules and prevents them from violating them unintentionally.

Of all the Execution Policies, Restricted is enabled by default:

"Restricted" is the default policy

  Restricted
    - Default execution policy.
    - Permits individual commands, but will not run scripts.
    - Prevents running of all script files, including formatting and configuration files (ps1xml), module script files (.psm1), and Windows PowerShell profiles (.ps1).

After reading the About_Execution_Policies file about execution policies and reading this default policy, it is clear to see that this will not allow the interface to be very useful when running PowerCLI. In fact, if the PowerCLI icon is clicked on without setting the execution policy to a less restrictive setting, the snap-in will not load.

It shows it in red to ensure that the error is read and understood. To bypass this, the Set-ExecutionPolicy command must be run under an administrator credential. Right-click on the icon for PowerCLI and select Run as Administrator. This enables the User Access Control for the PowerCLI/PowerShell window.

One of the following options must be selected:

AllSigned

- Scripts can run.
- Requires that all scripts and configuration files be signed be a trusted publisher, including script that you write on the local computer.
- Prompts you before running scripts from publishers that you have not yet classified as trusted or untrusted.
- Risks running signed, but malicious, scripts.

RemoteSigned

- Scripts can run.
- Requires a digital signature from a trusted publisher on script and configuration files that are downloaded from the Internet (including e-mail and instant messaging programs).
- Does not require digital signatures on scripts that you have written on the local computer (not downloaded from the Internet).
- Runs Scripts that are downloaded from the Internet and not signed, if the scripts are unblocked, such as by using the Unblock-File cmdlet.
- Risks running unsigned scripts from sources other than the Internet and signed, but malicious, scripts.

UnRestricted

- Unsigned scripts can run. (This risks running malicious scripts.)
- Warns the user before running scripts and configuration files that are downloaded from the Internet.

Bypass

- Nothing is blocked and there are no warnings or prompts.
- This execution policy is designed for configurations in which a Windows PowerShell script is built in to a larger application or for configurations in which Windows PowerShell is the foundation for a program that has its own security model.

Undefined

- There is no execution policy set in the current scope.
- If the execution policy in all scopes is Undefined, the effective execution policy is Restricted, which is the default execution policy.

Typically, most environments use the RemoteSigned option as this allows the functionality to run scripts on other computers and allows some additional security from unsigned scripts. If the environment being set up is a highly secure environment, the AllSigned option may be used when proper Public Key Infrastructure (PKI) is set up. This functionality will not be described in this book, and the RemoteSigned option will be assumed for the remainder of the book:

Set-ExecutionPolicy RemoteSigned

Once the ExecutionPolicy is set, configuration of the interface window should be next as it requires the additional permissions of the Administrator account. Right-click on the Heading window, and select Properties.

The QuickEdit mode allows the right-clicking, copying, and pasting functionality of the Command window. This feature helps tremendously when doing quick one-liners, needing report information or just wanting a portion of a command for another.

Select the Layout tab at the top of the Options window.

Set Screen Buffer Size for Width and Height whenever possible. The width buffer should match the actual width size. This permits the interface to need limited scrolling when getting output. The height buffer should be large, up to 9999, but if memory is a concern for the window, reduce the buffer size. This buffer allows for the output of a command to exceed the window size. For example, if the Get-VM command produces a listing of 3000 VMs, having a small buffer may not allow the window to be scrolled back to view the entire output. If the buffer size is 250, then 250 lines of scroll back will be permitted.

The last thing to check is the PowerCLI configuration. If the environment being worked on has multiple vCenter servers, having the configuration support multiple systems simultaneously can be advantageous. By default, the configuration is to connect to a single vCenter at a time; however, if the session is connected to one vCenter and a second Connect-VIServer command is run, this message pops up on the interface window:

Working with multiple default servers?

Select [Y] if you want to work with more than one default servers. In this case, every time when you connect to a different server using
Connect-VIServer, the new server connection is stored in an array variable together with the previously connected servers. When you run a cmdlet and the target servers cannot be determined from the specified parameters, the cmdlet runs against all servers stored in the array variable.
    Select [N] if you want to work with a single default server. In this case, when you run a cmdlet and the target servers cannot be determined from the specified parameters, the cmdlet runs against the last connected server.

    WARNING: WORKING WITH MULTIPLE DEFAULT SERVERS WILL BE ENABLED BY DEFAULT IN A FUTURE RELEASE. You can explicitly set your own preference at any time by using the DefaultServerMode parameter of Set-PowerCLIConfiguration.

[Y] Yes  [N] No  [S] Suspend  [?] Help (default is "Y"): y

The Get-PowerCLIConfiguration command will show three scopes of the configuration, Session, User, and AllUsers. The standard setup will show the following output:

Based on the preceding command connecting to the second vCenter, the configuration will show the following output:

Now, to allow AllUsers by default, the command to enable that would be as follows:

Set-PowerCLIConfiguration –DefaultVIServerMode Multiple –confirm:$False

Finally, the output would be displayed as follows:

Although there are many other environment options that can be performed, these, in the author's opinion, are the most useful.