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

Docker Contexts

Using the host on each command that we use is redundant and error-prone. For example, a deployment may fail due to it reaching a different host because we omitted to specify the host when running the command and we executed a different command on our local host.

For this case, Docker Contexts can be of help.

By creating contexts, we can switch our Docker configuration to multiple contexts and pick the right context per case.

So, let’s create a context for our EC2 host:

$ docker context create ec2-remote --docker host=ssh://[email protected]

Although we have created the context, we are still in the default context. Let’s switch to the recently created context:

$ docker context use ec2-remote

Run the following command:

$ docker run -it --rm redis

Check the results on the server:

ssh [email protected] docker ps
CONTAINER ID   IMAGE     COMMAND      ...