Public/Functions/Other/Save-WebFile.ps1
|
<#
.SYNOPSIS Downloads a file from the internet and returns a Get-Item Object .DESCRIPTION Downloads a file from the internet and returns a Get-Item Object .LINK https://github.com/OSDeploy/OSD/tree/master/Docs #> function Save-WebFile { [CmdletBinding()] [OutputType([System.IO.FileInfo])] param ( [Parameter(Position = 0, Mandatory, ValueFromPipelineByPropertyName)] [Alias('FileUri')] [System.String] $SourceUrl, [Parameter(ValueFromPipelineByPropertyName)] [Alias('FileName')] [System.String] $DestinationName, [Alias('Path')] [System.String] $DestinationDirectory = (Join-Path $env:TEMP 'OSD'), #Overwrite the file if it exists already #The default action is to skip the download [System.Management.Automation.SwitchParameter] $Overwrite, [System.Management.Automation.SwitchParameter] $WebClient ) #================================================= # Values #================================================= Write-Verbose "SourceUrl: $SourceUrl" Write-Verbose "DestinationName: $DestinationName" Write-Verbose "DestinationDirectory: $DestinationDirectory" Write-Verbose "Overwrite: $Overwrite" Write-Verbose "WebClient: $WebClient" #================================================= # DestinationDirectory #================================================= if (Test-Path "$DestinationDirectory") { Write-Verbose "Directory already exists at $DestinationDirectory" } else { New-Item -Path "$DestinationDirectory" -ItemType Directory -Force -ErrorAction Stop | Out-Null } #================================================= # Test File #================================================= $DestinationNewItem = New-Item -Path (Join-Path $DestinationDirectory "$(Get-Random).txt") -ItemType File if (Test-Path $DestinationNewItem.FullName) { $DestinationDirectory = $DestinationNewItem | Select-Object -ExpandProperty Directory Write-Verbose "Destination Directory is writable at $DestinationDirectory" Remove-Item -Path $DestinationNewItem.FullName -Force | Out-Null } else { Write-Warning 'Unable to write to Destination Directory' break } #================================================= # DestinationName #================================================= if ($PSBoundParameters['DestinationName']) { } else { $DestinationNameUri = $SourceUrl -as [System.Uri] # Convert to Uri so we can ignore any query string $DestinationName = $DestinationNameUri.AbsolutePath.Split('/')[-1] } Write-Verbose "DestinationName: $DestinationName" #================================================= # WebFileFullName #================================================= $DestinationDirectoryItem = (Get-Item $DestinationDirectory -Force).FullName $DestinationFullName = Join-Path $DestinationDirectoryItem $DestinationName #================================================= # OverWrite #================================================= if ((-not ($PSBoundParameters['Overwrite'])) -and (Test-Path $DestinationFullName)) { Write-Verbose 'DestinationFullName already exists' Get-Item $DestinationFullName -Force } else { #================================================= # Download #================================================= $SourceUrl = [Uri]::EscapeUriString($SourceUrl.Replace('%', '~')).Replace('~', '%') # Substitute and replace '%' to avoid escaping os Azure SAS tokens Write-Verbose "Testing file at $SourceUrl" #================================================= # Test for WebClient Proxy #================================================= $UseWebClient = $false if ($WebClient -eq $true) { $UseWebClient = $true } elseif (([System.Net.WebRequest]::DefaultWebProxy).Address) { $UseWebClient = $true } elseif (!(Test-CommandCurlExe)) { $UseWebClient = $true } if ($UseWebClient -eq $true) { [Net.ServicePointManager]::SecurityProtocol = [Net.ServicePointManager]::SecurityProtocol -bor [Net.SecurityProtocolType]::Tls1 $WebClient = New-Object System.Net.WebClient $WebClient.DownloadFile($SourceUrl, $DestinationFullName) $WebClient.Dispose() } else { Write-Verbose "cURL Source: $SourceUrl" Write-Verbose "Destination: $DestinationFullName" Write-Verbose 'Requesing HTTP HEAD to get Content-Length and Accept-Ranges header' $remote = Invoke-WebRequest -UseBasicParsing -Method Head -Uri $SourceUrl $remoteLength = $remote.Headers.'Content-Length' $remoteAcceptsRanges = ($remote.Headers.'Accept-Ranges' | Select-Object -First 1) -eq 'bytes' $curlCommandExpression = "& curl.exe --insecure --location --output `"$DestinationFullName`" --url `"$SourceUrl`"" if ($host.name -match 'PowerShell ISE Host') { #PowerShell ISE will display a NativeCommandError, so progress will not be displayed $Quiet = Invoke-Expression ($curlCommandExpression + ' 2>&1') } else { Invoke-Expression $curlCommandExpression } #================================================= # Continue interrupted download #================================================= if (Test-Path $DestinationFullName) { $localExists = $true } $RetryDelaySeconds = 1 $MaxRetryCount = 10 $RetryCount = 0 while ( $localExists ` -and ((Get-Item $DestinationFullName).Length -lt $remoteLength) ` -and $remoteAcceptsRanges ` -and ($RetryCount -lt $MaxRetryCount) ) { Write-Verbose "Download is incomplete, remote server accepts ranges, will retry in $RetryDelaySeconds second(s)" Start-Sleep -Seconds $RetryDelaySeconds $RetryDelaySeconds *= 2 # retry with exponential backoff $RetryCount += 1 $curlCommandExpression = "& curl.exe --insecure --location --continue-at - --output `"$DestinationFullName`" --url `"$SourceUrl`"" if ($host.name -match 'PowerShell ISE Host') { #PowerShell ISE will display a NativeCommandError, so progress will not be displayed $Quiet = Invoke-Expression ($curlCommandExpression + ' 2>&1') } else { Invoke-Expression $curlCommandExpression } } if ($localExists -and ((Get-Item $DestinationFullName).Length -lt $remoteLength)) { Write-Verbose "Download is incomplete after $RetryCount retries." Write-Warning "Could not download $DestinationFullName" $null } } #================================================= # Return #================================================= if (Test-Path $DestinationFullName) { Get-Item $DestinationFullName -Force } else { Write-Warning "Could not download $DestinationFullName" $null } #================================================= } } |