Windows Server ver.1709(Server Core)にPowerShell 6.0をインストールするスクリプト

Install-PS60toServerCore.ps1

# for Windows Server Core
& {
    # configurations
    $PS_VERSION = "6.0.0-beta.9"
    $PSInstaller = [PSCustomObject]@{
        Uri = "https://github.com/PowerShell/PowerShell/releases/download/v$PS_VERSION/PowerShell-$PS_VERSION-win-x64.msi";
        OutFile = Join-Path $env:TEMP "PowerShell-$PS_VERSION-win-x64.msi";
        InstallLog = Join-Path $env:TEMP "PowerShell-$PS_VERSION-win-x64-install.log";
        Sha256 = "D8A194C8944C4680F27406AC5B341971C546C04279A47C927FAB10D6F5CBFF2A";
        Destination = "C:\Program Files\PowerShell\$PS_VERSION";
    }
    $RemotingInstaller = [PSCustomObject]@{
        Uri = "https://raw.githubusercontent.com/PowerShell/PowerShell/master/src/powershell-native/Install-PowerShellRemoting.ps1"
        OutFile = Join-Path $env:TEMP "Install-PowerShellRemoting.ps1";
    }
    
    # download
    Invoke-WebRequest -Uri $PSInstaller.Uri -OutFile $PSInstaller.OutFile
    Invoke-WebRequest -Uri $RemotingInstaller.Uri -OutFile $RemotingInstaller.OutFile

    # verify
    if ((Get-FileHash -LiteralPath $PSInstaller.OutFile -Algorithm SHA256).Hash -eq $PSInstaller.Sha256) {
        Write-Host "Verified SHA256 hash..." -ForegroundColor Green
    } else {
        Write-Warning "Invalid SHA256 hash!"
        return 
    }
    if (Test-Path -LiteralPath $PSInstaller.Destination) {
        Write-Warning "$($PSInstaller.Destination) already exists!"
        return 
    }
    
    # Install PowerShell Core
    Write-Host "Install PowerShell Core..." -ForegroundColor Green
    Start-Process -FilePath "msiexec.exe" -ArgumentList @('/i', $PSInstaller.OutFile, '/qn', '/l*', $PSInstaller.InstallLog) -Wait -PassThru
    Write-Host "PowerShell installation complete!" -ForegroundColor Green

    # Install PSRemoting
    Write-Host "Install new PSRemoting endpoint..." -ForegroundColor Green
    # Install-PowerShellRemoting.ps1 invokes restarting WinRM Service.
    # So, if you run this script in remote session, the session disconnected.
    [ScriptBlock]::Create("$($RemotingInstaller.OutFile) -PowerShellHome `"$($PSInstaller.Destination)`" ").Invoke()
    Write-Host "PSRemoting endpoing configuration complete!" -ForegroundColor Green
}

Windows Server 2016以降のServer Coreで動作する、ハズ。
リモートセッションからこのスクリプトを実行すると途中でセッションが切断されるのでエラーが出ますが設定自体は完了しています。

PowerShell 6.0を使うには、

Enter-PSSession -ComputerName [computername] -Credential [credential] -ConfigurationName "powershell.6.0.0-beta.9"

の様に-ConfigurationNameを指定して接続してください。

ConfigurationNameは接続先サーバーで、

Get-PSSessionConfiguration -Name powershell.6.0.0*

とコマンドを実行すれば確認できます。