General purpose Octopus Deploy -> Install.ps1 bootstrapper

deploy.ps1

<#
.Synopsis
General-purpose Octopus Deploy boostrapper
Binds Octopus variables directly on to parameters on an install script, passing the rest as a hashtable
This means your Install script can itself have 'proper' parameters, making local testing easier
#>
param(
  $entryPoint = '.\Install.ps1'
)

function GetTypeName($obj){
    if($obj){
        $obj.GetType().Name;
    }else{
        'null';
    }
}

function ExpandVariables([string] $literalValue, $default){
    # This will do for now
    # If this becomes an issue, replace with a regex/replace
	# intent here is to allow passing of Octopus variables *as strongly typed* into install script
    $result = Invoke-Expression $literalValue;
    if($default -and !($result)){
        $default;
    }else{
        $result;
    }
}

function WriteErrorDetails($errorRecord){
	Write-Host "";
	Write-Warning "$errorRecord $($errorRecord.InvocationInfo.PositionMessage)"

	if($errorRecord.ScriptStackTrace){
		Write-Warning $errorRecord.ScriptStackTrace;
	}
    if($errorRecord.Exception){
        Write-Warning $errorRecord.Exception.GetBaseException().ToString();
    }
}

$scriptDir = Split-Path $MyInvocation.MyCommand.Path
pushd $scriptDir; 
try{
    # Make sure required Octopus params are in scope
    [void] (Get-Variable -Name:OctopusParameters)

    Write-Host "Installing to $OctopusEnvironmentName, using $entryPoint"
    
    # What we want to do is take in whatever Octopus passes us
    # map some of it to explicit parameters on deploy.ps1
    $scriptParameters = (Get-Command $entryPoint).Parameters;

    # Make sure we don't grab more than we want
    [void] $scriptParameters.Remove('properties');

    $boundArguments = @{};
    $otherArguments = @{};
    foreach($item in $OctopusParameters.GetEnumerator()){

        # Expand variables as required
        $value = $item.Value;
        if(($value -is [string]) -and ($value.StartsWith('$('))){
            $value = ExpandVariables $value;
        }

        if($scriptParameters.ContainsKey($item.Key)){
            #Write-Host -foreground Cyan $item.Key 'in installParameters';
            $boundArguments[$item.Key] = $value;

        }elseif($item.Key -notlike 'Octopus.*'){
			# Some of those dotted variable names that Octopus passes seem to kill psake
			# I think it's the ones which also have square brackets
			# eg: Octopus.Environment.MachinesInRole[ordw-sql-instance]
			# Kills the 'test-path variable:/$key' checks that psake does
			# Since we don't use them, filter them out (ie only pass in explicit project variables)
            $otherArguments[$item.Key] = $value;
        }
    }

    Write-Host "Setting install parameters:"
    foreach($item in $boundArguments.GetEnumerator()){
        $typeName = GetTypeName $item.Value;
        Write-Host ("`t{0} = {1} ({2})" -f $item.Key,$item.Value,$typeName);
    }

    Write-Host "Setting install properties:"
    foreach($item in $otherArguments.GetEnumerator()){
        $typeName = GetTypeName $item.Value;
        Write-Host ("`t{0} = {1} ({2})" -f $item.Key,$item.Value,$typeName);
    }

    $lastexitcode = 0;

    & $entryPoint @boundArguments -properties:$otherArguments; 

    # In case Install doesn't throw, explicitly bubble up exit code if needed
    if($lastexitcode -gt 0){
        Write-Warning "Failed: exitcode $lastexitcode";
        exit $lastexitcode
    }
    Write-Host "Completed";
    
}catch{
	WriteErrorDetails $_;
    exit 1;
}finally{
    popd;
}