Wrapper script for 'genUrlFromVersionAndChannel' function with support for v25 versioning and resolving to latest pre-release build

Invoke-McrGenUrlRoutine.ps1

<#
.SYNOPSIS
    Wrapper script for 'genUrlFromVersionAndChannel' function with support for v25 versioning and resolving to latest
    pre-release build
.PARAMETER DownloadUrl
    Specify the URL from which to obtain the package
.PARAMETER Channel
    Specify the release channel like 'test' or 'stable', etc.
.PARAMETER DockerVersion
    Specify the docker version you intend to install
.PARAMETER ContainerdVersion
    Specify the containerd version you intend to install
.EXAMPLE
    Invoke-McrGenUrlRoutine.ps1 -DockerVersion 23.0.16 -Verbose
.EXAMPLE
    Invoke-McrGenUrlRoutine.ps1 -DockerVersion 25.0.7 -Channel 'test-25.0' -Verbose
.NOTES
    Changes to genUrl... function based on https://github.com/Mirantis/docker-install-ee/pull/161
#>
[CmdletBinding(PositionalBinding=$FALSE, DefaultParameterSetName = 'engine')]
param (
        [string]$DownloadUrl = 'https://repos-internal.mirantis.com',

        [string]$Channel = 'test',
        
        [Parameter(ParameterSetName='engine', Mandatory=$true)]
        [ValidateNotNullOrEmpty()]
        [string]$DockerVersion,
        
        [Parameter(ParameterSetName='containerd', Mandatory=$true)]
        [ValidateNotNullOrEmpty()]
        [string]$ContainerdVersion
)

# Making script scope variables like the parent script install.ps1 has
[string] $intDownloadUrl = $DownloadUrl
[string] $intChannel = $Channel
[string] $genUrl = ''

if ($DockerVersion) {
    $version = $DockerVersion
    $packageName = 'docker'
}
elseif ($ContainerdVersion) {
    $version = $ContainerdVersion
    $packageName = 'containerd'
}

function verboseLog {
    Write-Verbose "$args"
}

function genUrlFromVersionAndChannel {
    # All parameters below will always have a value due to defaults
    param($pkgname, $channel, $version)

    if (($pkgname -eq 'Docker') -and (!($version -match '-'))) {
        Write-Verbose "Resolving latest build based on [$pkgname] version [$version]..."
        $url = "$script:intDownloadUrl`/win`/static`/$script:intChannel`/x86_64`/"
        $resp = Invoke-WebRequest -Uri $url -UseBasicParsing
        if ($resp.StatusCode -eq 200) {
            # RegEx and custom object code stolen from 'parsePackageVersions' function
            $tmpPkg = $resp.Links.href | findstr $pkgname-[0-9]
            $tmpPkgs = $tmpPkg.split(' ')
            # old $packageRegex = '^\s*(?<package>\w*)-(?<major>\d\d?)\.(?<minor>\d\d?)\.(?<patch>\d\d?)(m(?<mver>\d))?(-(?<pre>tp|rc|beta|nightly)\.?(?<prever>\d))?\.zip(\r|\n|\r\n)*$'
            $packageRegex = '^\s*(?<fullVersion>(?<major>\d\d?)\.(?<minor>\d\d?)\.(?<patch>\d\d?)(m(?<mver>\d))?((-|~+)(?<pre>tp|rc|beta|nightly|dev)\.?(?<prever>\d)?)?(\+fips)?)$'
            $releases = $tmpPkgs | Select-String -CaseSensitive -Pattern $packageRegex  | ForEach-Object {
                [PSCustomObject]@{
                    name    = $_.Matches.Value
                    package = $_.Matches[0].Groups['package'].Value
                    major   = [int]$_.Matches[0].Groups['major'].Value
                    minor   = [int]$_.Matches[0].Groups['minor'].Value
                    patch   = [int]$_.Matches[0].Groups['patch'].Value
                    mver    = [int]$_.Matches[0].Groups['mver'].Value
                    pre     = $_.Matches[0].Groups['pre'].Value
                    prever  = [int]$_.Matches[0].Groups['prever'].Value
                }
            }
            $releases = $releases | Sort-Object -Property major,minor,patch,mver,@{Expression={ 
                switch ($_.pre)
                {
                    ''   {0}
                    'rc' {1}
                    'tp' {2}
                }
            }; Descending=$true },prever
            $semverDockerVer = [System.Version] $version
            $latestBuild = $releases | Where-Object -FilterScript {
                ($_.major -eq $semVerDockerVer.Major) -and ($_.minor -eq $semVerDockerVer.Minor) -and ($_.patch -eq $semVerDockerVer.Build)
            } | Select-Object -Last 1
            if ($latestBuild) {
                Write-Verbose "Resolving latest build to [$($latestBuild.name)]."
                $version = ($latestBuild.name.substring(0,$latestBuild.name.LastIndexOf('.'))).Substring($pkgname.Length+1)
            }
            else {
                Write-Warning "Unable to resolve a [$pkgname] build corresponding to version [$version]"
            }
        }
        else {
            Write-Warning "Unexpected response code [$($resp.StatusCode)] when querying [$url]"
        }
    }
    $script:genUrl = ("$script:intDownloadUrl`/win`/static`/$channel`/x86_64`/$pkgname`-$version`.zip").ToLower()
    verboseLog "genUrl: $pkgname $channel $version $script:genUrl"
}

genUrlFromVersionAndChannel -pkgname $packageName -channel $Channel -version $version