Download files in Nano Server.

Get-WebFile.ps1

<#
.DESCRIPTION
    Downloads a file from the specified website.
.EXAMPLE
    Downloads Jetty 9.3.20.
        Get-WebFile -Uri 'http://central.maven.org/maven2/org/eclipse/jetty/jetty-distribution/9.3.20.v20170531/jetty-distribution-9.3.20.v20170531.zip' -OutFile 'C:\jetty-distribution-9.3.20.v20170531.zip'
.EXAMPLE
    Downloads Oracle Server JRE 8u131 and verifies hash.
        Get-WebFile -Uri 'http://download.oracle.com/otn-pub/java/jdk/8u131-b11/d54c1d3a095b4ff2b6607d096fa80163/server-jre-8u131-windows-x64.tar.gz' -OutFile 'C:\server-jre-8u131-windows-x64.tar.gz' -Cookie 'oraclelicense=accept-securebackup-cookie;' -Hash '1806EBE235EAB2B21C893ACBF0B287A392CE6B5EDFEA3286FC8FF7D6DEFB19CB'
.OUTPUTS
    Boolean. True if successful and if specified, hash value matches. Otheriwse, False is returned.
.NOTES
    Tested on Windows Server 2016, Nano Server.

    [Environment]::OSVersion

        Platform Version
        -------- -------
         Win32NT 10.0.14393.0

    $PSVersionTable

        Name                           Value
        ----                           -----
        PSVersion                      5.1.14393.1000
        SerializationVersion           1.1.0.1
        PSEdition                      Core
        PSRemotingProtocolVersion      2.3
        CLRVersion
        BuildVersion                   10.0.14393.1000
        PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
        WSManStackVersion              3.0

    Code from the following websites:
        https://stackoverflow.com/questions/20661652/progress-bar-with-httpclient
        https://github.com/dotnet/corefx/issues/6849
        https://stackoverflow.com/a/13287224
        https://serverfault.com/a/788951
#>
function Get-WebFile ($Uri, $OutFile, $Cookie, $Hash, $Algorithm='SHA256', $BufferSize=64KB)
{
    $ret = $false

    if ((Test-Path -Path $OutFile) -eq $false)
    {
        Add-Type -AssemblyName System.Net.Http
        $handler = New-Object -TypeName System.Net.Http.HttpClientHandler -Property @{UseCookies = $false}
        $client  = New-Object -TypeName System.Net.Http.HttpClient($handler) -Property @{BaseAddress = $Uri}

        if ($null -ne $Cookie -and $Cookie.Length -gt 0)
        {
            $client.DefaultRequestHeaders.Add('Cookie', $Cookie)
        }

        $client.GetAsync($Uri, [System.Net.Http.HttpCompletionOption]::ResponseHeadersRead) |% {
            $_.Wait()
            $response = $_.Result

            Write-Verbose -Message "Status: $($response.StatusCode)"

            if ($response.StatusCode -eq 'Redirect')
            {
                $ret = Get-WebFile -Uri $response.Headers.Location.OriginalString -OutFile $OutFile -Cookie $Cookie -BufferSize $BufferSize
            }
            elseif ($response.StatusCode -eq 'OK' -and $null -ne $response.Content.Headers.ContentLength)
            {
                $contentStream = $response.Content.ReadAsStreamAsync()
                $contentStream.Wait()

                $totalRead    = 0
                $totalReads   = 0
                $buffer       = New-Object -TypeName byte[] -ArgumentList $BufferSize
                $isMoreToRead = $true

                $downloadedFileStream = New-Object -TypeName System.IO.FileStream($OutFile, [System.IO.FileMode]::Create, [System.IO.FileAccess]::Write, [System.IO.FileShare]::None, $BufferSize, $true)

                do
                {
                    $read = $contentStream.Result.ReadAsync($buffer, 0, $BufferSize)
                    if ($read.Result -eq 0)
                    {
                        $isMoreToRead = $false
                        $downloadedFileStream.Close()
                    }
                    else
                    {
                        $downloadedFileStream.WriteAsync($buffer, 0, $read.Result) | Out-Null

                        $totalRead  += $read.Result
                        $totalReads += 1
                        $percentage  = $totalRead / $response.Content.Headers.ContentLength * 100

                        Write-Progress -Activity 'Writing web request' -status "Writing request stream... (Number of bytes written: $totalRead/$($response.Content.Headers.ContentLength)) = $percentage%" -PercentComplete $percentage
                    }
                } while ($isMoreToRead)

                $ret = $true
            }
            else
            {
                Write-Error -Message 'Unable to continue. No redirect, or OK status with file size returned.'
            }
        }

        $client.Dispose()
        $client = $null

        $handler.Dispose()
        $handler = $null
    }

    if ($null -ne $Hash -and $Hash.Length -gt 0)
    {
        $fileHash = Get-FileHash -Path $OutFile -Algorithm $Algorithm
        if ($fileHash.Hash -eq $Hash)
        {
            $ret = $true
        }
        else
        {
            Write-Error -Message "File hash does not match. Expected [$Hash], got [$($fileHash.Hash)]."
            $ret = $false
        }
    }

    $ret
}