Docker Best Practices Every Developer Should Know

In this Docker tutorial, we go beyond the basics and look at practical Docker best practices that make your containers more reliable, faster to build, smaller to ship, and easier to maintain. First, we fix one of the most common Docker Compose problems: "depends_on" does not mean that a service is ready. A database container can be started while Postgres itself is still not accepting connections. This is why your backend may crash with "connection refused", restart, and get stuck in a loop. The proper fix is to use a Docker healthcheck and wait for the database to become healthy. Finally, we explain multi-stage builds and Docker cleanup. Multi-stage builds help separate build-time tools from the production runtime image, which leads to cleaner, smaller, and more predictable containers. And because Docker does not clean up old images, containers, volumes, or build cache automatically, we also look at "docker system df" and "docker system prune". What you will learn: Why "depends_on" only controls container start order Why a started container does not mean the service inside is ready How Docker healthchecks solve startup timing problems How to wait for a healthy database before starting a backend What Docker build context is How Docker layer cache works How Dockerfile command order affects rebuild speed Why dependencies should usually be installed before copying application code What multi-stage builds are Why build environments and runtime environments should be separated How multi-stage builds reduce image size and improve production cleanliness How to inspect Docker disk usage How to clean unused Docker containers, images, networks, and cache Why Docker is an engineering discipline, not magic #Docker #DevOps #Containers #DockerCompose #SoftwareEngineering #backend #docker #coding #softwareengineering #code #containers