Sometimes you need to restrict access to an Azure subscription, resource group or a resource in order to prevent accidental deletion or modification of same by other users. With Azure resource Manager you can lock your resources in two levels.
CanNotDelete Authorized users can read and modify a resource, but they can’t delete it.
ReadOnly Authorized users can read from a resource, but they can’t delete it or perform any actions on it. The permission on the resource is restricted to the Reader role.
The ReadOnly lock be trick in certain situations. For an example a ReadOnly lock placed in a storage account prevents all users from listing the keys as the list keys operation is handled through a POST request since the returned keys are available for write operations. When you apply a lock at a parent, all child resources inherit the same lock. For an example if you apply a lock in a resource group all the resources in it will inherit same and even resources you add later will inherit same.
Locking with PowerShell
Following snippet demonstrates how you can apply a resource lock using PowerShell.
New-AzureRmResourceLock –LockLevel <either CanNotDelete or ReadOnly> –LockName <Lock Name> –ResourceName <resource name> –ResourceType <resource type> –ResourceGroupName <resource group name>
Here you should provide the exact resource type. For a complete list for available Azure resource providers please refer this article.