Operations → Runtime Infrastructure
Docker
A platform and tooling ecosystem for building, running, and distributing containers.
Where it fits
Docker is a tool for building and running containers. It belongs in Operations because it helps package software with its runtime environment.
Mental model
Docker packages an application and its dependencies into an image. Containers run instances of that image with process isolation and a consistent filesystem view.
Example
A backend service can be packaged into a Docker image and run the same way on a laptop, CI runner, or production container platform.
Common mistakes
- Treating containers as full virtual machines.
- Building huge images with unnecessary tools.
- Baking secrets into images.
Related concepts
Container, container image, Kubernetes, CI/CD pipeline, deployment.