1_OctopusVariables.ps1

$OctopusURL = "" #Octopus URL
$APIKey = "" #Octopus APIKey
$projectname = "" #Name of the project
$nuGetPath = ""
$pkdex = Import-Csv ""
if (-not (Test-Path $NugetPath)) {
    Write-Error "Cannot find nuget at path $NugetPath\nuget.exe"
    throw
}
$NugetExe = "$NugetPath\nuget.exe"
$nugetInstallOctopusClient = "&$NugetExe install Octopus.Client -ExcludeVersion -OutputDirectory $psscriptRoot"
Write-Output $nugetInstallOctopusClient
Invoke-Expression $nugetInstallOctopusClient
$octopusClientFolder = "$psscriptRoot\Octopus.Client\lib\net45"
if (-not (Test-Path $octopusClientFolder)) {
    Throw "It appears that the nuget install hasn't worked for Octopus.Client, check output above to see whats going on"
}

$nugetInstallNewtonsoftJson = "&$NugetExe install Newtonsoft.Json -ExcludeVersion -OutputDirectory $psscriptRoot"
Write-Output $nugetInstallNewtonsoftJson
Invoke-Expression $nugetInstallNewtonsoftJson
$netwonSoftClientFolder = "$psscriptRoot\Newtonsoft.Json\lib\net45"
if (-not (Test-Path $netwonSoftClientFolder)) {
    Throw "It appears that the nuget install hasn't worked for NetwonSoft.Json, check output above to see whats going on"
}
Add-Type -Path "$netwonSoftClientFolder\Newtonsoft.Json.dll"
Add-Type -Path "$octopusClientFolder\Octopus.Client.dll"
$endpoint = new-object Octopus.Client.OctopusServerEndpoint ($OctopusURL, $APIKey)
$c = new-object Octopus.Client.OctopusRepository $endpoint
Write-Output "Locating project $projectname. This may take some time..."
$project = $c.Projects.FindByName($projectname)
if ($null -eq $project.Name) {
    Write-Error "Project $projectname not found!"
    throw
}
Write-Output "Found project $($project.Name)"
$variableSet = $c.VariableSets.Get($project.links.variables)
foreach ($pkmn in $pkdex) {
    if ($variableSet.Variables.Name.Contains($pkmn.Name) -eq $true) {
        Write-Output "Variable$($pkmn.Name) exists. Checking if value matches..."
        $variable = $variableSet.Variables | Where-Object {$_.Name -eq $pkmn.Name}
        if ($variable.Value -eq $pkmn.Value) {
            Write-Output "Value of $($pkmn.Name) matches..."
        }
        else {
            Write-Output "Variable $($pkmn.Name) exists but value different. Updating to match value stored in csv..."
            $variable.Value = $($pkmn.Value)    
        }
    }
    else {
        $variable = New-Object Octopus.Client.Model.VariableResource
        $variable.name = $($pkmn.Name)
        $variable.Value = $($pkmn.Value)
        $variable.IsSensitive = $false 
        $variableSet.Variables.Add($variable)
        Write-Output "Adding var $($variable.name) to variable set. "
    }
    try {
        if ($pkmn.EnvironmentScope) {
            Write-Output "$($variable.name) has environment scoping. Updating to match value stored in csv. This may take some time..."
            $environments = $pkmn.EnvironmentScope -Split ","
            $octopusEnvironment = $c.Environments.FindByNames($environments)
            $variable.Scope.Add([Octopus.Client.Model.Scopefield]::Environment, (New-Object Octopus.Client.Model.ScopeValue($octopusEnvironment.Id)))  
        }
    }
    catch {
        Out-Null
    }
}
$variableSet = $c.VariableSets.Modify($variableSet)

2_samplecsv.csv

Name, Value, EnvironmentScope
myFirstVar, 5, Dev
mySecondVar,4,"Dev, Test"
myThirdVar, 5,	 PreProd
myFourthVar, 10, "Dev, PreProd"  
myFifthVar, 34, "Test, Dev"  
mySixthhVar, 34