New-VesterConfig.ps1

function New-VesterConfig {
    <#
    .SYNOPSIS
    Generates a Vester config file from settings in your existing VMware environment.

    .DESCRIPTION
    New-VesterConfig is designed to be a quick way to get started with Vester.

    Vester needs one config file for each vCenter server it interacts with. To
    help speed up this one-time creation process, New-VesterConfig uses PowerCLI
    to pull current values from your environment to store in the config file.
    
    You'll be prompted with the list of Clusters/Hosts/VMs/etc. discovered, and
    asked to choose one of each type to use as a baseline; i.e. "all my other
    hosts should be configured like this one." Those values are displayed
    interactively, and you can manually edit them as desired.

    Optionally, advanced users can use the -Quiet parameter. This suppresses
    all host output and prompts. Instead, values are pulled from the first
    Cluster/Host/VM/etc. found alphabetically. Manual review afterward of the
    config file is strongly encouraged if using the -Quiet parameter.

    It outputs a single Config.json file at \Vester\Configs, which may require
    admin rights. Optionally, you can use the -OutputFolder parameter to
    specify a different folder to store the Config.json file.

    .EXAMPLE
    New-VesterConfig
    Ensures that you are connected to only one vCenter server.
    Based on all Vester test files found in '\Vester\Tests', the command
    discovers values from your environment and displays them, occasionally
    prompting for a selection of which cluster/host/etc. to use.
    Outputs a new Vester config file to '\Vester\Configs\Config.json',
    which may require admin rights.

    .EXAMPLE
    New-VesterConfig -Quiet -OutputFolder "$env:USERPROFILE\Desktop"
    -Quiet suppresses all host output and prompts, instead pulling values
    from the first cluster/host/etc. found alphabetically.
    Upon completion, Config.json will be created on your Desktop.

    .NOTES
    This command relies on the Pester and PowerCLI modules for testing.

    "Get-Help about_Vester" for more information.

    .LINK
    https://wahlnetwork.github.io/Vester

    .LINK
    https://github.com/WahlNetwork/Vester
    #>
    [CmdletBinding()]
    param (
        # Select a folder to create a new Config.json file inside
        [Parameter(Mandatory = $False)]
        [ValidateScript({Test-Path $_ -PathType Container})]
        [object]$OutputFolder = "$(Split-Path -Parent $PSScriptRoot)\Configs",
        [Parameter(Mandatory = $False)]
        [string]$Datacenter = '*',
        [Parameter(Mandatory = $False)]
        [string]$Cluster = '*',
        [Parameter(Mandatory = $False)]
        [string]$DatastoreCluster = '*',
        [Parameter(Mandatory = $False)]
        [string]$VMHost = '*',
        [Parameter(Mandatory = $False)]
        [string]$VM = '*',
        [Parameter(Mandatory = $False)]
        [string]$VDS = '*'
    )

    # Must have only one vCenter connection open
    # Potential future work: loop through all vCenter connections
    If ($DefaultVIServers.Count -lt 1) {
        Write-Warning 'Please connect to vCenter before running this command.'
        throw 'A single connection with Connect-VIServer is required.'
    } ElseIf ($DefaultVIServers.Count -gt 1) {
        Write-Warning 'Vester config files are designed to be unique to each vCenter server.'
        Write-Warning 'Please connect to only one vCenter before running this command.'
        Write-Warning "Current connections:  $($DefaultVIServers -join ' / ')"
        throw 'A single connection with Connect-VIServer is required.'
    }
    Write-Verbose "vCenter: $($DefaultVIServers.Name)"

    # TODO: Make this a param? Or keep hardcoded?
    Write-Verbose "Assembling Vester files within $(Split-Path -Parent $PSScriptRoot)\Tests\"
    $GetVesterTest = "$(Split-Path -Parent $PSScriptRoot)\Tests\" | Get-VesterTest -Simple
    # Appending to a list is faster than rebuilding an array
    $VesterTestSuite = New-Object 'System.Collections.Generic.List[PSCustomObject]'

    # For each *.Vester.ps1 file found
    $GetVesterTest | ForEach-Object {
        # Do the necessary Split-Path calls once and save them for later
        $TestObj = [PSCustomObject]@{
            Full   = $_
            Parent = Split-Path (Split-Path $_ -Parent) -Leaf
            Leaf   = Split-Path $_ -Leaf
        }
        $VesterTestSuite.Add($TestObj)
    }

    # Grabs the high level test scopes.
    # Under Vester\Test the folders named: Cluster, DSCluster, Host, etc
    $ScopeList = ($VesterTestSuite | Select-Object -Property Parent -Unique).Parent
    Write-Verbose "Scopes supplied by test files: $($ScopeList -join ' | ')"

    # Builds out the config
    $config = [ordered]@{}
    $config.vcenter = @{vc = $DefaultVIServers.Name}
    $config.scope = [ordered]@{
        datacenter = $Datacenter
        cluster    = $Cluster
        dscluster  = $DatastoreCluster
        host       = $VMHost
        vm         = $VM
        vds        = $VDS
    }

    # Gathers the supplied inventory items
    Write-Verbose "Gathering inventory objects from $($DefaultVIServers.Name)"
    $vCenter    = $DefaultVIServers.Name
    $DatacenterObject = Get-Datacenter -Name $config.scope.datacenter -Server $vCenter
    $ClusterObject    = Get-Cluster -Location $DatacenterObject -Name $config.scope.cluster
    $DSClusterObject  = $DatacenterObject | Get-DatastoreCluster -Name $config.scope.dscluster
    $VMHostObject     = $ClusterObject | Get-VMHost -Name $config.scope.host
    $VMObject         = $ClusterObject | Get-VM -Name $config.scope.vm
    $NetworkObject    = $DatacenterObject | Get-VDSwitch -Name $config.scope.vds -ErrorAction Stop

    # Group tests by their scope
    ForEach ($Scope in $ScopeList) {
        Write-Verbose "Processing all tests for scope $Scope"

        # Loop through each test file applicable in the current scope
        # Couldn't resist calling each file a Vest. Sorry, everyone
        ForEach ($Vest in $VesterTestSuite | Where-Object Parent -eq $Scope) {
            Write-Verbose "Processing test file $($Vest.Leaf)"
            
            # Import all variables from the current .Vester.ps1 file
            . $Vest.Full

            $Object = switch ($Scope) {
                'vCenter'    {$vCenter}
                'Datacenter' {$DatacenterObject}
                'Cluster'    {$ClusterObject}
                'DSCluster'  {$DSClusterObject}
                'Host'       {$VMHostObject}
                'VM'         {$VMObject}
                'Network'    {$NetworkObject}
                # If not scoped properly, don't know what object to check
                Default      {$null}
            }

            # TODO: Should probably offload this to a private function
            $CfgLine = (Select-String -Path $Vest.Full -Pattern '\$cfg') -replace '.*\:[0-9]+\:',''
            $CfgLine -match '.*\$cfg\.([a-z]+)\.([a-z]+)$' | Out-Null

            # Run the $Actual script block, storing the result in $Result
            If ($Object -and ($Result = & $Actual) -ne $null) {
                # Call module private function Set-VesterConfigValue to add the entry
                Set-VesterConfigValue -Value ($Result -as $Type)
            } Else {
                # Inventory $Object doesn't exist, or $Actual returned nothing
                # Populate with null value; Invoke-Vester will skip this test
                Set-VesterConfigValue -Value $null
            } #if $Object and $Result
        } #foreach $Vest

        # Formats the results for this scope in an ordered hashtable
        Write-Host ''
        Write-Host '  # Config values for scope ' -NoNewline
        Write-Host "$Scope" -ForegroundColor Green
        # Only gets the enumerator if values exist
        $Sorted = If($config.$Scope){ $config.$Scope.GetEnumerator() | Sort-Object Name }
        $Sorted
        $config.$Scope = [ordered]@{}
        $Sorted | Foreach-Object { $config.$Scope.Add($_.Name, $_.Value) }
    } #foreach $Scope

    Write-Verbose "Creating config file at $OutputFolder\Config.json"
    Try {
        $config | ConvertTo-Json | Out-File $OutputFolder\Config.json -ErrorAction Stop
        Write-Host "`nConfig file created at " -ForegroundColor Green -NoNewline
        Write-Host "$OutputFolder\Config.json"
        Write-Host 'Edit the file manually to change any displayed values.'
    } Catch {
        Write-Warning "`nFailed to create config file at $OutputFolder\Config.json"
        Write-Warning 'Have you tried running PowerShell as an administrator?'
    }
}