Docker & Containers
Learn about containerization with Docker and related technologies.
Why Containers Changed Everything
Before containers, deploying software meant wrestling with environment inconsistencies - "it works on my machine" was a daily frustration. Docker solved this by packaging applications with everything they need to run, making deployments reproducible from a developer laptop to a production cluster. Today, containers are the standard unit of deployment for startups and enterprises alike.
At Wizard Tech Services, our web development projects are containerized by default, ensuring smooth handoffs and consistent environments. We also help teams containerize existing applications and set up orchestration as part of our automation and infrastructure services.
Containers vs. VMs
Virtual machines emulate entire operating systems and take minutes to boot. Containers share the host OS kernel and start in milliseconds, using a fraction of the memory. Use VMs when you need full OS isolation; use containers for application-level packaging and rapid scaling.
Dev-to-Prod Parity
Use Docker Compose locally and Kubernetes in production to keep your environments as similar as possible. The same Dockerfile builds the same image everywhere, eliminating configuration drift and "works on my machine" bugs.
YAML files define your entire application stack in one place. Learn how docker-compose.yml works, essential Compose commands, and see real-world examples including a modded Valheim game server and a Portainer deployment.
Two ways to run Docker - the Desktop GUI application for Mac/Windows or the command-line Engine on Linux. Compare features, resource usage, and learn which approach fits your workflow.
A web-based management UI for Docker - start, stop, and inspect containers from your browser. Deploy stacks from Compose files, manage multiple hosts, and use app templates for one-click deployments.
Health checks, log aggregation, resource metrics, and alerting for your containers. Covers Docker's built-in logging, Prometheus + Grafana stacks, Uptime Kuma, and terminal tools like ctop and Lazydocker.
Containers package your app, runtime, libraries, and config into one portable unit that runs identically anywhere. Covers the container lifecycle, volumes for persistent data, port mapping, and environment variable injection.
Docker images are built in layers via Dockerfile instructions. Write multi-stage builds for smaller images, tag versions, push to Docker Hub or GitHub Container Registry, and scan for vulnerabilities.
Docker Desktop vs CLI
Two ways to run Docker - a graphical application or the command line. Here is when to use each.
A GUI application for Windows, macOS, and Linux that bundles Docker Engine, Docker CLI, Docker Compose, and Kubernetes into a single install with a visual management interface.
Best For
- Beginners learning Docker concepts visually
- Windows and macOS users (handles VM layer)
- Quick container inspection and log viewing
- Built-in Kubernetes cluster for local testing
Limitations
- Requires a paid subscription for large businesses
- Higher resource usage (runs a VM on Mac/Windows)
- Not suited for headless servers
The command-line Docker Engine installed directly on Linux. No GUI, no VM overhead - just the daemon, CLI, and Compose plugin running natively on the host kernel.
Best For
- Linux servers and production environments
- Headless servers with SSH-only access
- CI/CD pipelines and automation scripts
- Lower resource overhead - no VM layer
Limitations
- Steeper learning curve for beginners
- No built-in GUI (use Portainer for web UI)
- Linux-only (Mac/Windows need Desktop or VM)
For servers and Linux desktops, install Docker Engine directly without Docker Desktop:
# Ubuntu / Debian
$ sudo apt update
$ sudo apt install docker.io docker-compose-v2
$ sudo usermod -aG docker $USER
$ newgrp docker
# Verify installation
$ docker --version
$ docker compose version
For development on Mac/Windows: Docker Desktop is the simplest path - it handles the VM layer, includes Compose, and gives you visual container management.
For Linux servers and production: Install Docker Engine directly via CLI. Add Portainer if you want a web UI for management. This is the setup we use for our hosting and automation services.
For learning: Start with Docker Desktop to visualize what containers, images, and volumes look like. Once comfortable, switch to the CLI - it is faster and works everywhere.