Initial Azure Automation Automated Export Sample

This contains the powershell files for the auotmated export, a README.md
file explaining how to set up the automated export in azure automation,
and an update to the README.md file in the directory above describing
the automated export sample.

samples/manage/azure-automation-automated-export/AutoExportBlobRetention.ps1

@@ -0,0 +1,23 @@
+# The storage key for the storage account you are using.
+$storageKey = Get-AutomationVariable -Name "STORAGEKEYVARIABLENAME";
+# The name of the storage container you are using.
+$storageContainer = "STORAGECONTAINERNAME";
+# Set up the storage context for the storage account.
+$context = New-AzureStorageContext -StorageAccountName "STORAGEACCOUNTNAME" -StorageAccountKey $storageKey
+# Get all of the blobs in the storage account.
+$blobs = Get-AzureStorageBlob -Container $storageContainer -Context $context
+# Set the number of days that you want the blob to be stored for.
+$retentionInDays = 30
+
+foreach($blob in $blobs)
+{
+    # Get the current time to compare to the time that the blob was created.
+	$currentTime = Get-Date;
+    # If the blob is more than $retentionInDays old, delete it.
+	if(($currentTime - $blob.LastModified.DateTime).TotalDays -gt $retentionInDays)
+	{
+		echo ("Deleting blob " + $blob.Name)
+        # Delete the blob.e
+		Remove-AzureStorageBlob -Container $storageContainer -Context $context -Blob $blob.Name;
+	}
+}