Architecting Serverless Solutions

Now that we have built an application backed by a serverless backend, we have a very basic serverless architecture.

These components can be triggered by a much greater variety of events than the HTTP requests that we used previously, from records being inserted into a SQL database, to the temperature dropping below a certain level. They allow you to wire together a massive variety of systems, executing simple code on the messages along the way, if required. Serverless can change the way you integrate systems together.

Azure Functions have a sister service, also serverless, that was made specifically for integrations between systems. The service is called Azure Logic Apps, and it has a fantastic selection of prebuilt adapters for all sorts of services, including non-Microsoft ones. You can create an Azure Logic App without opening Visual Studio...

Architecting Greenfield Serverless Applications

A greenfield project (or product) is a new solution to a problem; it is not built on top of any existing application but usually is part of a wider business architecture.

Whenever a new greenfield project starts, technologists receive an often incomplete set of very approximate, high-level requirements. They then start to form an architecture to satisfy those requirements, and keep in mind any other requirements that they suspect may appear. Modern development approaches recognize the need for architecture to be as extensible and flexible as possible, because that initial set of requirements is never, ever complete, and today's greenfield projects are tomorrow's legacy systems.

Techniques such as adding an API layer and making the subcomponents modular can be used to make applications flexible and extensible.

How can we...

Integrating Legacy Applications

If you are operating on a totally greenfield project, everything that we have discussed so far will work perfectly. The full variety of SaaS, PaaS, and IaaS integrations means that your serverless code will happily operate with any set of requirements. Where things tend to get tricky is legacy systems. Whether they are written in a programming language that is no longer supported inside your firm, are monolithic and difficult to extend, or are completely black box, these applications do tend to perform vital business functions and therefore cannot be left out in the cold. If there is an API then integration is straightforward, but sadly there often isn't one. Either a gargantuan development effort needs to be made to replace them or they need to be integrated into the new architecture.

Serverless can come to the rescue for most cases, although...

Summary

In this chapter, you've covered techniques for building greenfield serverless architectures (where you can exploit the full potential of serverless) and techniques for integrating existing applications. You now know how to connect to a wide variety of services through Logic Apps, a simple-to-use serverless product. You know several approaches for integrating your existing applications into a serverless architecture, from creating a custom API connector to adding event triggering on to an existing database.

In this book, you have started with an introduction to Azure Functions. Here you analyzed the real benefits of Serverless Computing and the technical basis of Azure Functions. Once your Azure Function was deployed, you integrated it with other Azure Services and logged with Application Insights.

Then, you secured the server with API Keys. Lastly, you implemented...