Book Image

A Developer's Essential Guide to Docker Compose

By : Emmanouil Gkatziouras
Book Image

A Developer's Essential Guide to Docker Compose

By: Emmanouil Gkatziouras

Overview of this book

Software development is becoming increasingly complex due to the various software components used. Applications need to be packaged with software components to facilitate their operations, making it complicated to run them. With Docker Compose, a single command can set up your application and the needed dependencies. This book starts with an overview of Docker Compose and its usage and then shows how to create an application. You will also get to grips with the fundamentals of Docker volumes and network, along with Compose commands, their purpose, and use cases. Next, you will set up databases for daily usage using Compose and, leveraging Docker networking, you will establish communication between microservices. You will also run entire stacks locally on Compose, simulate production environments, and enhance CI/CD jobs using Docker Compose. Later chapters will show you how to benefit from Docker Compose for production deployments, provision infrastructure on public clouds such as AWS and Azure, and wrap up with Compose deployments on said infrastructure. By the end of this book, you will have learned how to effectively utilize Docker Compose for day-to-day development.
Table of Contents (19 chapters)
1
Part 1: Docker Compose 101
6
Part 2: Daily Development with Docker Compose
12
Part 3: Deployment with Docker Compose

Selecting the Compose files to run

In the previous section, one of the issues we stumbled upon is the fact that we run the application’s Compose file altogether. However, modularization is in place since we split the compose file into multiple parts. Thus, the next step would be to run debug and test different modules of the application individually.

Using Hoverfly

Since our applications depend on each other, the only viable option is to run the applications together until we find an alternative. For development and testing purposes, we can mock some of the services that introduce dependencies and still be able to run our application locally.

For this purpose, Hoverfly (https://hoverfly.io/) can be of significant help. Hoverfly can intercept traffic and mock requests and responses.

We will spin up a Hoverfly instance with a capture mode in Compose:

services:
  hoverfly:
    image: spectolabs/hoverfly
    ports...