In SDL Web 8, there are far more things managed via Windows PowerShell than there used to be in previous releases of the product. On the one hand, this makes a lot of sense, as the PowerShell offers a clean and standardised way to interact with various settings and configurations. Still, not everyone is familiar enough with the PowerShell to immediately get the most out of the cmdlets provided by the SDL modules. In fact, today, someone told me quite excitedly that they'd discovered the Get-TtmMapping cmdlet. My first question was "Have you run Get-Command on the SDL modules?"

The point is that with the PowerShell, quite a lot of attention is paid to discoverability. Naming conventions are specified so that you have a good chance of being able to effectively guess the name of the command you need, and other tools are provided to help you list what is available. The starting point is Get-Module. To list the modules available to you, you invoke it like this: 

get-module -listavailable

This will list a lot of standard Windows modules, but on your SDL Web 8 Content Manager server, you should see the following at the bottom of the listing: 

 Directory: C:\Program Files (x86)\SDL Web\bin\PowerShellModules

ModuleType Version Name ExportedCommands
---------- ------- ---- ----------------
Binary 0.0.0.0 Tridion.ContentManager.Automation {Clear-TcmPublicationTarget, Get-TcmApplicationIds, Get-Tc...
Binary 0.0.0.0 Tridion.TopologyManager.Automation {Add-TtmSiteTypeKey, Add-TtmCdEnvironment, Add-TtmCdTopolo...

This gives you the names of the available SDL modules. From here, you can dig in further to list the commands in each module, like this: 

get-command -module Tridion.TopologyManager.Automation

This gives you the following output: 

CommandType     Name                           ModuleName
-----------     ----                           ----------
Cmdlet          Add-TtmCdEnvironment           Tridion.TopologyManager.Automation
Cmdlet          Add-TtmCdTopology              Tridion.TopologyManager.Automation
Cmdlet          Add-TtmCdTopologyType          Tridion.TopologyManager.Automation
Cmdlet          Add-TtmCmEnvironment           Tridion.TopologyManager.Automation
Cmdlet          Add-TtmMapping                 Tridion.TopologyManager.Automation
Cmdlet          Add-TtmSiteTypeKey             Tridion.TopologyManager.Automation
Cmdlet          Add-TtmWebApplication          Tridion.TopologyManager.Automation
Cmdlet          Add-TtmWebsite                 Tridion.TopologyManager.Automation
Cmdlet          Clear-TtmCdEnvironment         Tridion.TopologyManager.Automation
Cmdlet          Clear-TtmMapping               Tridion.TopologyManager.Automation
Cmdlet          Disable-TtmCdEnvironment       Tridion.TopologyManager.Automation
Cmdlet          Enable-TtmCdEnvironment        Tridion.TopologyManager.Automation
Cmdlet          Export-TtmCdStructure          Tridion.TopologyManager.Automation
Cmdlet          Get-TtmCdEnvironment           Tridion.TopologyManager.Automation
Cmdlet          Get-TtmCdTopology              Tridion.TopologyManager.Automation
Cmdlet          Get-TtmCdTopologyType          Tridion.TopologyManager.Automation
Cmdlet          Get-TtmCmEnvironment           Tridion.TopologyManager.Automation
Cmdlet          Get-TtmMapping                 Tridion.TopologyManager.Automation
Cmdlet          Get-TtmWebApplication          Tridion.TopologyManager.Automation
Cmdlet          Get-TtmWebsite                 Tridion.TopologyManager.Automation
Cmdlet          Import-TtmCdStructure          Tridion.TopologyManager.Automation
Cmdlet          Remove-TtmCdEnvironment        Tridion.TopologyManager.Automation
Cmdlet          Remove-TtmCdTopology           Tridion.TopologyManager.Automation
Cmdlet          Remove-TtmCdTopologyType       Tridion.TopologyManager.Automation
Cmdlet          Remove-TtmCmEnvironment        Tridion.TopologyManager.Automation
Cmdlet          Remove-TtmMapping              Tridion.TopologyManager.Automation
Cmdlet          Remove-TtmSiteTypeKey          Tridion.TopologyManager.Automation
Cmdlet          Remove-TtmWebApplication       Tridion.TopologyManager.Automation
Cmdlet          Remove-TtmWebsite              Tridion.TopologyManager.Automation
Cmdlet          Set-TtmCdEnvironment           Tridion.TopologyManager.Automation
Cmdlet          Set-TtmCdTopology              Tridion.TopologyManager.Automation
Cmdlet          Set-TtmCdTopologyType          Tridion.TopologyManager.Automation
Cmdlet          Set-TtmCmEnvironment           Tridion.TopologyManager.Automation
Cmdlet          Set-TtmMapping                 Tridion.TopologyManager.Automation
Cmdlet          Set-TtmWebApplication          Tridion.TopologyManager.Automation
Cmdlet          Set-TtmWebsite                 Tridion.TopologyManager.Automation
Cmdlet          Sync-TtmCdEnvironment          Tridion.TopologyManager.Automation

I'm sure you can see immediately that this gives you a great overview of the possibilities - probably including some things you hadn't thought of. You can also see how they follow the standard naming conventions. But now that you know what commands are available, how do you use them? What parameters do they accept? What are they for? 

It might sound obvious, but indeed, the modules come with batteries included, including built-in help. So, for example, to learn more about a command, you can simply do this: 

help Get-TtmMapping

or if your Unix roots are showing, this does the same thing:

man Get-TtmMapping

The output looks like this: 

NAME
 Get-TtmMapping

SYNOPSIS
 Gets one or all Mappings from the Topology Manager.

SYNTAX
 Get-TtmMapping [[-Id] <String>] [-TtmServiceUrl <String>] [<CommonParameters>]

DESCRIPTION
 The Get-TtmMapping cmdlet retrieves a Mapping with the specified Id.
 If Id parameter is not specified, list of all Mappings will be returned.

RELATED LINKS
 Add-TtmMapping
 Set-TtmMapping
 Remove-TtmMapping

REMARKS
 To see the examples, type: "get-help Get-TtmMapping -examples".
 For more information, type: "get-help Get-TtmMapping -detailed".
 For technical information, type: "get-help Get-TtmMapping -full".
 For online help, type: "get-help Get-TtmMapping -online"

By using these few simple tools, you can accelerate your learning process and find the relevant commands easily and quickly. Happy hunting! 

Well it's taken me a while to get this far, but I'm finally getting a bit further through the process of installing Web 8. My first attempt had foundered when I failed to accept the installer's defaults - it really, really wants to run the various services on different ports instead of by configuring host headers!

Anyway - this time I accepted the defaults and the content manager install seemed to go OK. (I suppose I'll set up the host header configuration manually at some point once I'm a bit more familiar with how everything hangs together.) So now I'm busy installing and configuring content delivery, and specifically the Discovery service. I got as far as this point in the documentation, where it tells you to run 

java -jar discovery-registration.jar update

This didn't work. Instead I got an error message hinting that perhaps the service ought to be running first. So after a minute or two checking whether I'd missed a step in the documentation, I went to tridion.stackexchange.com and read a couple of answers. Peter Kjaer had advised someone to run start.ps1, so I went back to have a better look. Sure enough, in the Discovery service directory, there's a readme file, with instructions for starting the service from the shell, and also for running it as a service. (This also explains why I couldn't find the Windows service mentioned in the following step in the installation documentation.)

Anyway - so I tried to run the script, and discovered that it expects to find JAVA_HOME in my environment. So I added the environment variable, and but then when I started the script it spewed out a huge long java exception saying it couldn't find the database I'd configured. But... nil desperandum, community to the rescue, and it turned out to be a simple fix.

So with that out of the way, I ran the other script - to install it as a service, and I now have a working discovery service... next step: registration