42 posts tagged with "Containers"

Your production Go binary is 15 MB. Your Docker image is 1.1 GB. That is not a rounding error — it is a sign that you are shipping an entire operating system, a compiler toolchain, and hundreds of packages you will never use at runtime. Multi-stage builds fix this in a way that feels almost too easy.

Your container exits immediately with code 1. Or it starts but the application is unreachable. Or it runs for an hour and then OOMs. Docker gives you powerful debugging tools, but most people only know docker logs. Here is the full toolkit for diagnosing container problems.

You have built a Docker image. Now what? You need somewhere to store it so your CI/CD pipeline, your Kubernetes cluster, or your teammates can pull it. That somewhere is a container registry. But which one? The answer depends on your cloud provider, team size, budget, and how much you enjoy YAML.

Anyone can write a Dockerfile that works. FROM ubuntu, RUN apt-get install everything, COPY . ., done. It builds. It runs. And it is a 1.8 GB security nightmare that takes 10 minutes to deploy. Here are 12 rules that separate a working Dockerfile from a production-ready one.

You have a web app that needs Postgres, Redis, and Nginx. Running four separate docker run commands with all their flags is painful. Forgetting one flag breaks everything. Docker Compose lets you define your entire application stack in a single YAML file and manage it with one command.

Two containers are running on the same machine. One is your API server, the other is your database. They need to talk to each other. But how? They are isolated processes — they do not share localhost. Understanding Docker networking is the difference between containers that communicate effortlessly and hours of debugging "connection refused" errors.