Lesson 20

Dockerizing full stack applications

This page explains how multiple connected services become one Docker-managed system instead of a single isolated app container.

Frontend

The frontend serves the user interface and often talks to the backend through HTTP requests.

Backend

The backend handles APIs, business logic, validation, and communication with storage or other services.

Database

The database stores persistent data and needs extra attention around volumes, readiness, and backups.

Typical full stack flow

Browser

Frontend container

Backend container

Database container

Optional real-world layer

Nginx in front

Frontend for UI

Backend for API

Database for data

Why Docker helps full stack systems

Each service keeps its own dependencies.
Setup becomes easier to repeat across machines.
Networking between services becomes clearer.
Compose can manage the stack in one place.

What becomes more important now

Service naming such as `frontend`, `backend`, `db`.
Environment variables for connection settings.
Volumes for data persistence.
Startup order and readiness checks.

Example Compose thinking

services:
  frontend:
  backend:
  db:

Even this tiny shape already shows the main idea: one project can have several services with different responsibilities.

Common beginner mistake

Treating a full stack application like one giant container often makes maintenance harder. Docker usually works better when each major service has its own clear role.

How the lessons connect here

Volumes
Database or upload data must persist.

Networks
Services must communicate by container or service name.

Compose
The whole stack should start together cleanly.

Environment variables
Frontend and backend often need different config values.

Next page: Lesson 21 goes deeper into the database side of Docker, especially persistence, backup thinking, and migrations.