Get Azure File from snapshot with php - php

Question

Is there any documentation to get a SAS URL to download a file from a Snapshot of a Azure Share File?
Using this is easy to download a direct Azure File with SAS, but not any snapshot:
GenerateFileDownloadLinkWithSAS (https://github.com/Azure/azure-storage-php/blob/master/samples/FileSamples.php)
Here my code:
use MicrosoftAzure\Storage\Common\Exceptions\ServiceException;
use MicrosoftAzure\Storage\Common\Internal\Resources;
use MicrosoftAzure\Storage\Common\Internal\StorageServiceSettings;
use MicrosoftAzure\Storage\Common\Models\Range;
use MicrosoftAzure\Storage\Common\Models\Metrics;
use MicrosoftAzure\Storage\Common\Models\RetentionPolicy;
use MicrosoftAzure\Storage\Common\Models\ServiceProperties;
use MicrosoftAzure\Storage\File\FileRestProxy;
use MicrosoftAzure\Storage\File\FileSharedAccessSignatureHelper;
use MicrosoftAzure\Storage\File\Models\CreateShareOptions;
use MicrosoftAzure\Storage\File\Models\ListSharesOptions;
use MicrosoftAzure\Storage\File\Models\ListDirectoriesAndFilesOptions;
function MapFileURL($shareName,$filePath)
{
global $fileRestProxy;
global $mapConString;
$prepareFilePath = implode('/', array_map(function ($v)
{
return rawurlencode($v);
}, explode('/', $filePath))
);
// Create a SharedAccessSignatureHelper
$settings = StorageServiceSettings::createFromConnectionString($mapConString);
$accountName = $settings->getName();
$accountKey = $settings->getKey();
$helper = new FileSharedAccessSignatureHelper(
$accountName,
$accountKey
);
$endDate=MapIsoDate(time() + 13300);
// Generate a file readonly SAS token
// Refer to following link for full candidate values to construct a service level SAS
// https://learn.microsoft.com/en-us/rest/api/storageservices/constructing-a-service-sas
$sas = $helper->generateFileServiceSharedAccessSignatureToken(
Resources::RESOURCE_TYPE_FILE,
$shareName . "/" . $prepareFilePath,
'r', // Read
$endDate
);
$connectionStringWithSAS = Resources::FILE_ENDPOINT_NAME.'='.'https://'.$accountName.'.'.Resources::FILE_BASE_DNS_NAME.';'.Resources::SAS_TOKEN_NAME.'='.$sas;
$fileClientWithSAS = FileRestProxy::createFileService($connectionStringWithSAS);
// Get a downloadable file URL
$fileUrlWithSAS = sprintf(
'%s%s?%s',
(string)$fileClientWithSAS->getPsrPrimaryUri(),
$shareName . "/" . $prepareFilePath,
$sas
);
return $fileUrlWithSAS;
}
What would be missing to be able to download the file from a Azure File snapshot?

Answer 1

What would be missing to be able to download the file from a Azure
File snapshot?
What you need to do is append the share's snapshot date/time to your SAS URL. Something like:
https://account.file.core.windows.net/share/file.png?sastoken&snapshot=2021-05-01T13:49:56.0000000Z

Answer 2

Here is the code that works:
function MapSnapshotFileURL($shareName, $filePath, $snapshotTime)
{
global $fileRestProxy;
global $mapConString;
// Preparar path para enviar a la función azure.
$prepareFilePath = implode('/', array_map(function ($v)
{
return rawurlencode($v);
}, explode('/', $filePath))
);
// Create a SharedAccessSignatureHelper
$settings = StorageServiceSettings::createFromConnectionString($mapConString);
$accountName = $settings->getName();
$accountKey = $settings->getKey();
$helper = new FileSharedAccessSignatureHelper(
$accountName,
$accountKey
);
$endDate=MapIsoDate(time() + 13300);
//$endDate='2019-07-16T08:30:00Z';
// Generate a file readonly SAS token
// Refer to following link for full candidate values to construct a service level SAS
// https://learn.microsoft.com/en-us/rest/api/storageservices/constructing-a-service-sas
$sas = $helper->generateFileServiceSharedAccessSignatureToken(
Resources::RESOURCE_TYPE_FILE,
$shareName . "/" . $prepareFilePath,
'r', // Read
$endDate // '2020-01-01T08:30:00Z' // A valid ISO 8601 format expiry time
);
$connectionStringWithSAS = Resources::FILE_ENDPOINT_NAME.'='.'https://'.$accountName.'.'.Resources::FILE_BASE_DNS_NAME.';'.Resources::SAS_TOKEN_NAME.'='.$sas;
$fileClientWithSAS = FileRestProxy::createFileService($connectionStringWithSAS);
// Get a downloadable file URL
$fileUrlWithSAS = sprintf(
'%s%s?%s&%s',
(string)$fileClientWithSAS->getPsrPrimaryUri(),
$shareName . "/" . $prepareFilePath,
$sas,
"snapshot=".$snapshotTime
);
return $fileUrlWithSAS;
}