Resource Locks and Policies

When considering production workloads for your Azure environment there are some simple features that ensure the safety of your workloads that are being overlooked. The features I’m referring to are Resource Locks and Resource Manager Policies (RMPs).

Both features allow you greater control over your environment with minimal administrative effort. In my opinion, regardless of whether you are running production workloads or not, you should at the very least be using Locks and RMPs as a preventative method of control over your deployments.

Locks are a very simple and quick tool that can prevent changes to your environment in an instant. They can be applied at different tiers of your environment. Depending on your governance model, you might want to apply at the subscription, resource group or resource level, all are possible. Locks have only two basic operations:

  • CanNotDelete means authorized users can still read and modify a resource, but they can’t delete the resource.
  • ReadOnly means authorised users can read a resource, but they can’t delete or update the resource. Applying this lock is similar to restricting all authorised users to the permissions granted by the Reader role.

Locks obey inheritance, so if you apply at resource group level, all resources contained within will receive the applied lock, the same is true for subscription level assignments.

Of the built-in roles, only Owner and User Access Administrator are granted the ability to apply and remove locks. In general, my recommendation is that all production resources are assigned a CanNotDelete lock. Environments such as UAT where performance etc is being monitored are more suited to a ReadOnly lock to ensure consistent environment results.

RMPs can be used individually or in conjunction with Locks to ensure even more granular control of your environment. RMPs define what you can and cannot do with your environment. For example, all resources created must be located in the European datacentres, or, all resources created must have a defined set of tags applied.

In terms of scope, RMPs can be applied exactly the same as Locks and also obey inheritance. A common scenario here is to apply a policy at subscription level to specify your allowed datacentres, then if you have a traditional IT Resource Group design, specify policies at RG level allowing only specific VM sizes for dev/test to manage cost.

There are many combinations that can be put to use to allow you greater control of your environment. At the end of the day, Azure allows for huge flexibility by design, but it is important for many companies for both security and cost management reasons to be able to exercise a degree of control over that flexibility.

A little tip if you are using both features, make sure you apply a CanNotDelete Lock to your important RMPs!

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s