Book Image

Docker for Serverless Applications

By : Chanwit Kaewkasi
Book Image

Docker for Serverless Applications

By: Chanwit Kaewkasi

Overview of this book

Serverless applications have gained a lot of popularity among developers and are currently the buzzwords in the tech market. Docker and serverless are two terms that go hand-in-hand. This book will start by explaining serverless and Function-as-a-Service (FaaS) concepts, and why they are important. Then, it will introduce the concepts of containerization and how Docker fits into the Serverless ideology. It will explore the architectures and components of three major Docker-based FaaS platforms, how to deploy and how to use their CLI. Then, this book will discuss how to set up and operate a production-grade Docker cluster. We will cover all concepts of FaaS frameworks with practical use cases, followed by deploying and orchestrating these serverless systems using Docker. Finally, we will also explore advanced topics and prototypes for FaaS architectures in the last chapter. By the end of this book, you will be in a position to build and deploy your own FaaS platform using Docker.
Table of Contents (15 chapters)
Title Page
Packt Upsell
Contributors
Preface
Index

A function as a Glue


Besides writing a simple processor, the technique in this section is one of the simplest forms of using functions. We have a bank backend with REST APIs exposed. So we write a function as a Glue to hide the complex interface of the backend. In this example, we use Go as the language to implement the function.

The scenario is that we have a REST API server and we want to unify it with another similar service. In the example in this chapter, we have two banking backends with different ways of interaction. The first one is a web-based UI without a REST interface, another one is the REST API in this section:

func main() {
  input := os.Args[1]

  // OpenWhisk params are key/value paris
  params := map[string]interface{}{}
  err := json.Unmarshal([]byte(input), params)
  if err != nil {
    fmt.Printf(`{"error":"%s", "input": "%s"}`, err.Error(), string(input))
    os.Exit(-1)
  }

  entry := Entry{
    Account: Account{
      Id: params["accountId"].(string),
    },
    Amount...