• 3 min read

Rules Engine for Azure Front Door and Azure CDN is now generally available

Today we are announcing the general availability of the Rules Engine feature on both Azure Front Door and Azure Content Delivery Network (CDN).

Today we are announcing the general availability of the Rules Engine feature on both Azure Front Door and Azure Content Delivery Network (CDN). Rules Engine places the specific routing needs of your customers at the forefront of Azure’s global application delivery services, giving you more control in how you define and enforce what content gets served from where. Both services offer customers the ability to deliver content fast and securely using Azure’s best-in-class network. We have learned a lot from our customers during the preview and look forward to sharing the latest updates going into general availability.

How Rules Engine works

We recently talked about how we are building and evolving the architecture and design of Azure Front Door Rules Engine. The Rules Engine implementation for Content Delivery Network follows a similar design. However, rather than creating groups of rules in Rules Engine Configurations, all rules are created and applied to each Content Delivery Network endpoint. Content Delivery Network Rules Engine also boasts the concept of a global rule which acts as a default rule for each endpoint that always triggers its action.

General availability capabilities

Azure Front Door

The most important feedback we heard during the Azure Front Door Rules Engine preview was the need for higher rule limits. Effective today, you will be able to create up to 25 rules per configuration, for a total of 10 configurations, giving you the ability to create a total of 250 rules across your Azure Front Door. There remains no additional charge for Azure Front Door Rules Engine.

Azure Content Delivery Network 

Similarly, Azure Content Delivery Network limits have been updated. Through preview, users had access to five total rules including the global rule for each CDN endpoint. We are announcing that as part of general availability, the first five rules will continue to be free of charge, and users can now purchase additional rules to customize CDN behavior further. We’re also increasing the number of match conditions and actions within each rule to ten match conditions and five actions.

Rules Engine scenarios

Rules Engine streamlines security and content delivery logic at the edge, a benefit to both current and new customers of either service. Different combinations of match conditions and actions give you fine-grained control over which users get what content and make the possible scenarios that you can accomplish with Rules Engine endless.

For instance, it’s an ideal solution to address legacy application migrations, where you don’t want to worry about users accessing old applications or not knowing how to find content in your new apps. Similarly, geo match and device identification capabilities ensure that your users always see the optimal content their location and device are using. Implementing security headers and cookies with Rules Engine can also ensure that no matter how your users come to interact with the site, they are doing so over a secure connection, preventing browser-based vulnerabilities from impacting your site.

Here are some additional scenarios that Rules Engine empowers:

  • Enforce HTTPS, ensure all your end-users interact with your content over a secure connection.
  • Implement security headers to prevent browser-based vulnerabilities like HTTP Strict-Transport-Security (HSTS), X-XSS-Protection, Content-Security-Policy, X-Frame-Options, as well as Access-Control-Allow-Origin headers for Cross-Origin Resource Sharing (CORS) scenarios. Security-based attributes can also be defined with cookies.
  • Route requests to mobile or desktop versions of your application based on the patterns in the contents of request headers, cookies, or query strings.
  • Use redirect capabilities to return 301, 302, 307, and 308 redirects to the client to redirect to new hostnames, paths, or protocols.
  • Dynamically modify the caching configuration of your route based on the incoming requests.
  • Rewrite the request URL path and forward the request to the appropriate backend in your configured backend pool.
  • Optimize media delivery to tune the caching configuration based on file type or content path (Azure Content Delivery Network only).

Next steps

We look forward to working with more customers using both Azure Front Door and Content Delivery Network Rules Engine. For more information, please see the documentation for Azure Front Door Rules Engine and Azure Content Delivery Network Rules Engine.