CircleCI 2.0 implemented build support using Docker executors. Upon releasing it, we quickly realized that one of the biggest barriers that CircleCI users encountered was a lack of experience with Docker. In this post, we will discuss Docker and some of the basic commands users should become familiar with.
What is Docker
Here is a simplified definition of Docker:
“Docker is a platform for developers and sysadmins to develop, deploy, and run applications using containers.”
Docker is also referred to as an application packaging tool that enables applications to be configured and packaged into a Docker image that can be used to spawn Docker containers that run instances of the application. It provides many benefits including runtime environment isolation, consistency via code, and portability. Docker containers can run on any operating system that supports the Docker Engine. To our benefit, most operating systems do support it.