As Cloudflare Workers, and other Serverless platforms, continue to drive down costs while making it easier for developers to stand up globally scaled applications, the migration of legacy applications is becoming increasingly common. In this post, I want to show how easy it is to migrate such an application onto Workers. To demonstrate, I’m going to use a common migration scenario: moving a legacy application — on an old compute platform behind a VPN or in a private cloud — to a serverless compute platform behind zero-trust security.

Wait but why?

Before we dive further into the technical work, however, let me just address up front: why would someone want to do this? What benefits would they get from such a migration? In my experience, there are two sets of reasons: (1) factors that are “pushing” off legacy platforms, or the constraints and problems of the legacy approach; and (2) factors that are “pulling” onto serverless platforms like Workers, which speaks to the many benefits of this new approach. In terms of the push factors, we often see three core ones:

• Legacy compute resources are not flexible and must be constantly maintained, often leading to capacity constraints or excess cost;
• Maintaining VPN credentials is cumbersome, and can introduce security risks if not done properly;
• VPN client software can be challenging for non-technical users to operate.

Similarly, there are some very key benefits “pulling” folks onto Serverless applications and zero-trust security:

• Instant scaling, up or down, depending on usage. No capacity constraints, and no excess cost;
• No separate credentials to maintain, users can use Single Sign On (SSO) across many applications;
• VPN hardware / private cloud; and existing compute, can be retired to simplify operations and reduce cost

#serverless week #cloudflare workers #javascript #developers