Add support for SAS URL in Read-DbaBackupHeader and Get-DbaBackupInformation

[david-garcia-garcia]

Type of Change

New feature

Unless I am missing something, it is currently not possible to do database restores from a collection of backups stored in Azure Blobs (automatically). With the fixes in this PR I hope to be able to have restore automation to support the backups that can be made using Hallengren backup solution to Azure Blobs.

Purpose

Add support for Shared Access Singature URL's in Get-DbaBackupInformation and Read-DbaBackupHeader

Approach

Small tweaks to support URLS with SAS. See comments in code.

Commands to test

Read-DbaBackupHeader and Get-DbaBackupInformation

[david-garcia-garcia]

This was the only way I could find to obtain the blobs in a container through powershell, I really don't like the approach but it's the only way I could come up with.

[david-garcia-garcia]

The deal here is... Read-DbaBackupHeader is actually working right now. If you want to use a SAS URL, you need to remove the SAS from the URL and add the SAS credential in MSSQL. This is here for convenience, you either use an explicit credential or a SAS URL, and if it is a SAS url, MSSQL wants it without the SAS token.

[david-garcia-garcia]

I can foresee a nice WTF if you call this method with a SAS URL for a container, and you have NOT created the SAS credential in MSSQL, because this method will properly enumerate the individual blobs, but when calling Read-DbaBackupHeader, they are going to get a permission denied issue (I could enumerate, but I could not read them...)

[david-garcia-garcia]

No need for any of this, you can extract the URL's manually and pass them in to Get-DbaBackupInformation

$ctx = New-AzStorageContext -StorageAccountName $backupUrl.storageAccountName -SasToken $backupUrl.sasToken;
$blobs = Get-AzStorageBlob -Container $backupUrl.container -Context $ctx -Prefix $backupUrl.prefix |
Where-Object { ($_.AccessTier -ne 'Archive') -and ($_.Length -gt 0) };
        
$blobUrls = $blobs | ForEach-Object { $backupUrl.baseUrl + $_.Name } 
$files = Get-DbaBackupInformation -SqlInstance $sqlInstance -Path $blobUrls | Where-Object { $_.Database -eq $databaseName };