Exercise3.md

Task 2 - The build

Estimated time to completion: 30-60 minutes

To kick off a new build, the script build.ps1 is going to be used. Whether or not you are in a build pipeline, the build script will create all artifacts in your current environment.

Remember to check the prerequisites!

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2.3 Add a new role

Now, your branch office in Frankfurt has requested a new role for WSUS servers. This requires you to configure the WSUS feature and set a registry key.

This new role should enable WSUS administrators to build on top of the basic infrastructure.

1. Let us now create a new role for a WSUS Server in the source\Roles folder. This role's YAML will subscribe to the configuration WindowsFeatures and will define configuration data (Settings) for the configuration.

   Create a new file in source\Roles named WsusServer.yml. Paste the following content into the new file and save it.

   Configurations:
   - WindowsFeatures
   
   WindowsFeatures:
     Names:
     - +UpdateServices

2. Now let us add a new node YAML DSCWS01.yml in the Test environment which is based on this role. Create the new file DSCWS01.yml in the folder source\AllNodes\Test. Paste the following content into the file and save it.

NodeName: '[x={ $Node.Name }=]'
Environment: '[x={ $File.Directory.BaseName } =]'
Role: WsusServer
Description: '[x= "$($Node.Role) in $($Node.Environment)" =]'
Location: Frankfurt
Baseline: Server

ComputerSettings:
  Name: '[x={ $Node.NodeName }=]'
  Description: '[x= "$($Node.Role) in $($Node.Environment)" =]'

NetworkIpConfiguration:
  Interfaces:
    - InterfaceAlias: DscWorkshop 0
      IpAddress: 192.168.111.113
      Prefix: 24
      Gateway: 192.168.111.50
      DnsServer:
        - 192.168.111.10
      DisableNetbios: true

PSDscAllowPlainTextPassword: True
PSDscAllowDomainUser: True

LcmConfig:
  ConfigurationRepositoryWeb:
    Server:
      ConfigurationNames: '[x={ $Node.NodeName }=]'

DscTagging:
  Layers:
    - '[x={ Get-DatumSourceFile -Path $File } =]'

Note: The YAML rendering does not always show the indention correctly. Please have a look at another node file to check the indention. To discover yaml syntax errors upfront, the VS Code plug-in YAML should help.

Once again, it is that easy. New roles (i.e. WsusServer), environments (i.e. Test) and nodes (i.e. DSCWS01) just require adding YAML files. The devil is in the details: Providing the appropriate configuration data for your configurations like the network configuration requires knowledge of the underlying infrastructure of course.

In order to build the new node DSCWS01 which uses the WsusServer role, simply start up the build again.

.\build.ps1

After the build has completed take a look at the new nodes resulting files.

NOTE: YAML syntax can be tricky so if you have errors during the build it very likely due to a not well formed YAML. Please use also the previously mentioned YAML VS Code plug-in.

2.4 Modify a role

Modifying a role is even easier as adding a new one. Let's try changing the default time server for all the file servers. If the setting effects all time servers, it must be defined in the FileServer role.

1. Open the FileServer.yml from your roles directory. We are modifying an already existing role definition now.

2. In order to change a configuration item, just modify or add to your YAML file:

RegistryValues:
  Values:
  - Key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\Parameters
    ValueName: NtpServer
    ValueData: pool.contoso.local,0x2
    ValueType: String
    Ensure: Present

1. After committing your changes, you can restart the build again to see your results in action. All file server artifacts that have been created will now have a modified MOF and RSoPs. You can either use the VSCode UI or the following commands:

git add .
git commit -m 'Modified the ntp server setting for the file server role.'
.\build.ps1

You should have a feeling now how easy it is to modify config data used by DSC when using Datum.

Please continue with Exercise 4 when your are ready.