In the previous article we learned how to create a Rails 6 Docker image and run it locally. While useful for demonstration purposes, it is not enough for a real-world web application. In addition to our main application code, there are other services that we also need, like a database, a queue system, storage and so on.

Docker Compose provides a way for us to describe how our entire application works using declarative code. Declarative code means that we specify the final state of our application, rather than specifying what steps are needed to create our application. This results in a simpler, more intuitive configuration. Continue Reading

In the Introduction to Docker article, we developed a good basic foundational knowledge about container technology. Now, we will take it one step further by creating and running a Rails 6 application exclusively using Docker. As of this writing, Rails 6 is the latest version of the Ruby on Rails web application framework.

Generating the Rails code

We learned previously that we can run Ruby code using Docker even without having Ruby in our local machine. We can also use the container’s shell and run commands directly in the container. Using these, let’s try to perform some commands in a container running Ruby 2.7: Continue Reading

Docker is perhaps responsible for the proliferation of containers in application development. The concept of containers is quite old, and can be traced back in the 1980s by chroot wherein different user spaces can be used within the same operating system. Once Docker was introduced however, it paved the way for further developments in containerization and changed the way how we develop and deploy software.

In this article we will discuss how to install and setup Docker in your local machine. Common Docker commands will be introduced that will equip you with foundational knowledge for tackling the next steps in application development using containers (such as Compose). Continue Reading