functions/invoke-d365azurestoragedownload.ps1

<#
.SYNOPSIS
Download a file to Azure
 
.DESCRIPTION
Download any file to an Azure Storage Account
 
.PARAMETER AccountId
Storage Account Name / Storage Account Id where you want to fetch the file from
 
.PARAMETER AccessToken
The token that has the needed permissions for the download action
 
.PARAMETER Blobname
Name of the container / blog inside the storage account you where the file is
 
.PARAMETER FileName
Name of the file that you want to download
 
.PARAMETER Path
Path to the folder / location you want to save the file
 
.PARAMETER GetLatest
Switch to tell the cmdlet just to download the latest file from Azure regardless of name
 
.EXAMPLE
Invoke-D365AzureStorageDownload -AccountId "miscfiles" -AccessToken "xx508xx63817x752xx74004x30705xx92x58349x5x78f5xx34xxxxx51" -Blobname "backupfiles" -FileName "OriginalUAT.bacpac" -Path "c:\temp"
 
Will download the "OriginalUAT.bacpac" file from the storage account and save it to "c:\temp\OriginalUAT.bacpac"
 
.EXAMPLE
Invoke-D365AzureStorageDownload -AccountId "miscfiles" -AccessToken "xx508xx63817x752xx74004x30705xx92x58349x5x78f5xx34xxxxx51" -Blobname "backupfiles" -Path "c:\temp" -GetLatest
 
Will download the file with the latest modified datetime from the storage account and save it to "c:\temp\".
The complete path to the file will returned as output from the cmdlet.
 
.EXAMPLE
$AzureParams = Get-D365ActiveAzureStorageConfig
Invoke-D365AzureStorageDownload @AzureParams -Path "c:\temp" -GetLatest
 
This will get the current Azure Storage Account configuration details
and use them as parameters to download the latest file from an Azure Storage Account
 
Will download the file with the latest modified datetime from the storage account and save it to "c:\temp\".
The complete path to the file will returned as output from the cmdlet.
 
.NOTES
The cmdlet supports piping and can be used in advanced scenarios. See more on github and the wiki pages.
 
#>

function Invoke-D365AzureStorageDownload {
    [CmdletBinding(DefaultParameterSetName = 'Default')]
    param (
        [Parameter(Mandatory = $false, Position = 1 )]
        [string] $AccountId = $Script:AccountId,

        [Parameter(Mandatory = $false, Position = 2 )]
        [string] $AccessToken = $Script:AccessToken,

        [Parameter(Mandatory = $false, Position = 3 )]        
        [string] $Blobname = $Script:Blobname,

        [Parameter(Mandatory = $true, ParameterSetName = 'Default', ValueFromPipelineByPropertyName = $true, Position = 4 )] 
        [Alias('Name')]
        [string] $FileName,

        [Parameter(Mandatory = $true, Position = 5 )]
        [string] $Path,

        [Parameter(Mandatory = $true, ParameterSetName = 'Latest', Position = 4 )]
        [switch] $GetLatest
    )

    BEGIN { 
        if ((Test-Path -Path $Path) -eq $false) {
            $null = New-Item -ItemType directory -Path $Path
        }

        if ( ([string]::IsNullOrEmpty($AccountId) -eq $true) -or 
            ([string]::IsNullOrEmpty($AccessToken)) -or ([string]::IsNullOrEmpty($Blobname))) {
            Write-PSFMessage -Level Host -Message "It seems that you are missing some of the parameters. Please make sure that you either supplied them or have the right configuration saved."
            Stop-PSFFunction -Message "Stopping because of missing parameters"
            return
        }
    }
    PROCESS {
        if (Test-PSFFunctionInterrupt) {return}    

        Invoke-TimeSignal -Start

        $storageContext = new-AzureStorageContext -StorageAccountName $AccountId -StorageAccountKey $AccessToken

        $cloudStorageAccount = [Microsoft.WindowsAzure.Storage.CloudStorageAccount]::Parse($storageContext.ConnectionString)

        $blobClient = $cloudStorageAccount.CreateCloudBlobClient()

        $blobcontainer = $blobClient.GetContainerReference($Blobname);


        try {
            if ($GetLatest.IsPresent) {
                $files = $blobcontainer.ListBlobs()
                $File = ($files | Sort-Object -Descending { $_.Properties.LastModified } | Select-Object -First 1)
    
                $NewFile = Join-Path $Path $($File.Name)

                $File.DownloadToFile($NewFile, [System.IO.FileMode]::Create)
            }
            else {
                $NewFile = Join-Path $Path $FileName

                $blockBlob = $blobcontainer.GetBlockBlobReference($FileName);
                $blockBlob.DownloadToFile($NewFile, [System.IO.FileMode]::Create)
            }

            [PSCustomObject]@{
                File     = $NewFile
                Filename = $FileName
            }
        }
        catch {
            Write-PSFMessage -Level Host -Message "Something went wrong while downloading the file from Azure" -Exception $PSItem.Exception
            Stop-PSFFunction -Message "Stopping because of errors"
            return
        }
        finally {
            Invoke-TimeSignal -End
        }
    }

    END {}
}