Refactor

Another Azure migration is to refactor, which involves making some changes to the application but not wholesale changes that completely change the code base. For instance, instead of moving the VM, only move the web application. This would require some configuration or code changes to make this happen, which we will discuss in depth in this chapter.

When I have done this, I do the following:

• Assess how to quickly modernize the app to leverage Azure better while keeping costs down
• Provide more code portability and code reuse
• Assess when I want a better DevOps and continuous innovation journey

I approach refactoring for Azure in the following way:

• I review the code to ensure that dependencies are able to run in the cloud
• I review data structures that might need to be moved into Azure
• I look for VPN/Express Route opportunities to leverage on-premise resources over wholesale moves.

An example of this was when I had a client that wanted to move their web frontends to Azure without moving the data repositories into Azure. I started the POC with a site-to-site VPN and then transitioned to ExpressRoute. This begins the process of moving in line with your Azure governance/plan process if you choose this process based on the plan. Let’s look at this process in the following diagram:

As you can see in the preceding diagram, we did not move the VM but moved the IIS applications to App Services and the data repositories to data instances. This will require us to make changes to the configuration and code updates to interact with these new instance-based services. This allows us to scale differently and control cost a bit better.