~/VibeHandbook
$39
≡
Read the BookReferencePhilosophyGet the PDFFAQ

Infrastructure

docker.com ↗

Containers

What it is

A container packages your app together with everything it needs to run — code, libraries, system tools — into one portable bundle. That bundle runs the same way on your laptop, a test server, or the cloud, which eliminates the classic "it works on my machine" problem. Docker is the most common tool for building them.

Strengths

  • Consistent environment everywhere — build once, run anywhere.
  • Full control over the runtime, OS packages, and dependencies.
  • No cold starts once running; good for steady traffic.
  • Portable across cloud providers, avoiding hard lock-in.
  • Supports any language or framework, including long-running processes.

Trade-offs

  • You manage more: base images, updates, and resource sizing.
  • Scaling isn't automatic unless you add an orchestrator (like Kubernetes), which adds real complexity.
  • A running container costs money even when idle.
  • Larger images mean slower builds and deploys.
  • Security patching of the image is your responsibility.

When to use it

Choose containers when you need a consistent, fully-controlled environment: apps with specific system dependencies, long-running services, background workers, or anything that outgrows the limits of serverless and edge functions.

Vibe coding fit

Containers are a strong AI-directed target because a Dockerfile is just a recipe, and agents are good at writing recipes. You can have the AI generate the Dockerfile, a .dockerignore, and the deploy commands, then iterate by reading build errors back to it. Tip: ask for a small base image (like alpine or a slim variant) and a multi-stage build — this keeps images lean, builds fast, and the attack surface small. Platforms like Fly.io, Google Cloud Run, and Railway can deploy a container with a single command.

# Dockerfile — multi-stage Node app
FROM node:20-slim AS build
WORKDIR /app
COPY package*.json ./
RUN npm ci
COPY . .
RUN npm run build

FROM node:20-slim
WORKDIR /app
COPY --from=build /app .
EXPOSE 3000
CMD ["node", "server.js"]

# Build and run locally
docker build -t my-app .
docker run -p 3000:3000 my-app