11 Akka ports

This chapter covers

Creating an HTTP server with Akka HTTP
Connecting through HTTP with actors from outside the cluster
Creating an gRPC server with Akka gRPC
Connecting through gRPC with actors from outside the cluster

In this chapter you will learn how to connect to an Actor system to send it messages from the outside. This is done so that any application can interact with Actors. You will learn how to create servers in Akka that provide endpoints that can be used by HTTP or gRPC clients.

11.1 Akka HTTP

This module builds on Akka Streams and shares its semantics. Its components are internally defined in terms of Sources, Flows and Sinks. However, these are hidden and your interaction with this API is through an expressive DSL that lets you create URL paths, manage requests and responses, and more.

Akka HTTP is a very comprehensive module that covers HTTP clients, HTTP servers, JSON and XML encoding, caching, and anything else you can think of to serve or use HTTP endpoints. However, this chapter focuses on the HTTP server you need to expose your actor system.

IMPORTANT

You can use the following code companion https://github.com/franciscolopezsancho/akka-topics/tree/main/chapter11a to check out the source code for the following examples. You can find the contents of any snippet or listing in the .scala file with the same name as the class, object or trait.

11.1.1 Akka HTTP Server

11.1.2 Path

11.1.3 Directives

11.1.4 Route directives

11.1.5 Complete

11.1.6 Traversing the Route

11.1.7 Failing

11.1.8 Marshalling/Unmarshalling

11.1.9 Akka HTTP communicating to Actors

11.1.10 Transform the Request

11.1.11 Transform to Response

11.2 Akka gRPC

11.2.1 The Protocol buffers side

11.2.2 The RPC side

11.2.3 Akka gRPC

11.2.4 In action

11.2.5 Running the service

11.2.6 Akka gRPC with an Actor

11.2.7 Running the example