A Lability definition to create an Azure DevOps Agent

BuildAgent.ps1

configuration BuildAgent {
    param (
        [ValidateNotNull()]
        [System.Management.Automation.PSCredential]$Credential,

        [string]$EnvPrefix,

        [Int]$RetryCount = 100,
        [Int]$RetryIntervalSec = 30
    )

    Import-DscResource -ModuleName xPSDesiredStateConfiguration -ModuleVersion 8.0.0.0
    Import-DscResource -ModuleName xStorage -ModuleVersion 2.9.0.0
    # a Black Marble modules that contain our specific functions (alteratives listed)
    Import-DscResource -ModuleName bmDscResources -ModuleVersion 1.7.6
     
    node $AllNodes.Where({$_.Role -eq 'BuildAgent'}).NodeName {

        $LocalAdminCredential = New-Object System.Management.Automation.PSCredential ("$($node.NodeName)\$($Credential.UserName)", $Credential.Password)

        LocalConfigurationManager {
            RebootNodeIfNeeded = $true
            AllowModuleOverwrite = $true
            ConfigurationMode = 'ApplyOnly'
            CertificateID = $Node.Thumbprint
            DebugMode = 'All'
        }

        # make sure Windows manages paging
        Script Paging {
            PsDscRunAsCredential = $LocalAdminCredential
            GetScript = { @{} }
            TestScript = {
                $computersys = Get-WmiObject Win32_ComputerSystem -EnableAllPrivileges;
                return $computersys.AutomaticManagedPagefile 
            }
            SetScript = {
                $computersys = Get-WmiObject Win32_ComputerSystem -EnableAllPrivileges;
                $computersys.AutomaticManagedPagefile = $True;
                $computersys.Put();
            }
        }

        # make sure the NIC has the name we expect
        Script NameNic {
            PsDscRunAsCredential = $LocalAdminCredential
            GetScript = { @{} }
            TestScript = {
                $adapters = get-netadapter
                $adaptor = $adapters | Where {$_.name -eq 'Ethernet'}
                $adaptor -ne $null
            }
            SetScript = {
                $adapter = get-netadapter | where {$_.Name.startswith("Ethernet") }
                if (!$adapter.count){
                    if ($adapter.Name -ne "Ethernet") {
                        rename-netadapter -name $adapter.name -newname "Ethernet"
                    }
                }
            }
        }

        # A slighly customised network config. Could be replaced by xIPAddress, xDnsServerAddress etc.
        bmNetwork NetworkConfiguration {
            DependsOn = "[script]NameNic"
            IsAzure = $false
            IPAddress = $Node.IPAddress
            PrefixLength = $Node.PrefixLength
            InterfaceAlias = $Node.InterfaceAlias
            AddressFamily = $Node.AddressFamily
            DefaultGateway = $Node.DefaultGateway
            DnsAddress = $Node.DnsAddress
          }

        # Add an extra disk
        xWaitforDisk Disk1 {
            DiskNumber = 1
            RetryIntervalSec = $RetryIntervalSec
            RetryCount = $RetryCount
        }
        xDisk AgentDisk {
            DiskNumber = 1
            DriveLetter = 'E'
        }
  
        # Set the Window supdate keys, a wrapper for registry settings
        bmWindowsUpdate SetWindowsUpdateKeys {
        }

        # Install agent
        Script AddBMPackages {
            PsDscRunAsCredential = $LocalAdminCredential
            GetScript = { @{} }
            TestScript = {
                if (Get-PSRepository | Where-Object SourceLocation -eq 'https://packages.blackmarble.co.uk/nuget/PowerShell') {
                    return $true
                }
                else {
                    return $false
                }
            }
            SetScript = {
                $RegisterSplat = @{
                    Name = 'BM'
                    SourceLocation = 'https://packages.blackmarble.co.uk/nuget/PowerShell'
                    PublishLocation = 'https://packages.blackmarble.co.uk/nuget/PowerShell'
                    InstallationPolicy = 'Trusted'
                }
                
                Register-PSRepository @RegisterSplat
            }
        }

        $AgentArguments = "--unattended --url $($ConfigurationData.AzureDevOps.Url) --auth pat --token $($ConfigurationData.AzureDevOps.Pat) --pool $($ConfigurationData.AzureDevOps.Pool) --agent $EnvPrefix$($Node.Nodename)-$(Get-Random -SetSeed (Get-Date).Second -Minimum 1 -Maximum 150) --work _work --runAsService --WindowsLogonAccount $($Credential.Username) --WindowsLogonPassword $($Credential.GetNetworkCredential().Password)"
        Script InstallAgent {
            GetScript = { @{} }
            TestScript = {
                Test-Path -Path "E:\Agent\.Agent"
            }
            SetScript = {
                Expand-Archive -Path C:\Bootstrap\Agent.zip -DestinationPath E:\Agent -Force

                Start-Process -FilePath E:\Agent\config.cmd -ArgumentList $Using:AgentArguments -Wait -RedirectStandardOutput C:\Bootstrap\Output.txt

                Get-Content -Path C:\Bootstrap\output.txt | Foreach-Object { Write-Verbose -Message $_ }
            }
            DependsOn = '[xDisk]AgentDisk'
        }
    }
}