Validate that a release and its packages can be deployed to an environment based on whether they have pre-release version numbers

Validate-ReleaseAndPackagesForEnvironment.ps1

$environment = $OctopusParameters['Octopus.Environment.Name']
$releaseNumber = $OctopusParameters['Octopus.Release.Number']
$packages = @(
    @{ 
        "Id" = $OctopusParameters['Octopus.Action[Update Database].Package.NuGetPackageId'];
        "Version" = $OctopusParameters['Octopus.Action[Update Database].Package.NuGetPackageVersion']
    },
    @{
        "Id" = $OctopusParameters['Octopus.Action[Deploy Website].Package.NuGetPackageId'];
        "Version" = $OctopusParameters['Octopus.Action[Deploy Website].Package.NuGetPackageVersion']
    }
)
$environmentReleaseMap = @{
    "Test" = "*";
    "UAT" = @("rc");
    "Pre-Production" = @();
    "Production" = @();
}

$releases = $environmentReleaseMap[$environment]
Write-Host "$environment allows [ $( $releases -join ", " ) ] pre-release package types within releases."

if ($releases -eq $null -or $releases -eq "*") {
    exit
}

function Get-PreReleaseType ($version) {
    $regex = [regex]"^(\d+.){2}\d+(-(?<prerelease>[A-z]+)\d+){1}$"
    $matches = $regex.Matches($version)

    foreach ($match in $matches) {
        $group = $match.Groups["prerelease"]
        if ($group -ne $null) {
            return $group.Value
        }
    }
}

function Validate-Release ($number) {
    Write-Host "Validating release $number can be deployed to $environment."

    $type = Get-PreReleaseType $number
    
    if ($type -eq $null) { Write-Host "Release does not have a pre-release version number."; }
    if ($type -ne $null) { Write-Host "Release has a pre-release ($type) version number."; }
        
    if ($type -ne $null -and $releases -notcontains $type) {
        throw "This release can not be deployed to $environment because it has a pre-release ($type) version number."
    }
}

function Validate-Package ($packageName, $packageVersion) {
    Write-Host "Validating $packageName $packageVersion can be deployed to $environment."

    $type = Get-PreReleaseType $packageVersion
    
    if ($type -eq $null) { Write-Host "$packageName is not a pre-release package."; }
    if ($type -ne $null) { Write-Host "$packageName is a pre-release ($type) package."; }
    
    if ($type -ne $null -and $releases -notcontains $type) {
        throw "This release can not be deployed to $environment because it contains a pre-release ($type) version of the $packageName package."
    }
}

Validate-Release $releaseNumber

$packages | %{ Validate-Package $_.Id $_.Version }