"Works on my machine" je 2026 izgovor koji nitko ne prihvaća. Docker rješava taj problem — svaki developer pokreće isto okruženje, deployovi reproducibilni, dependencies izolirani. Ovo je praktičan vodič što Docker je, kada ga koristit, i kako početi za PHP/Node/Laravel/Craft projekte.

Što je Docker

Docker = kontejnerizacija. Aplikacija + sve dependencies (OS biblioteke, runtime, config) pakovani u image. Image se pokreće kao container — isolated process na host serveru.

Kontejner nije VM. Dijeli kernel s host-om, ali file system, network, process space su izolirani.

Osnovne pojmove

Image — template (npr. php:8.2-fpm). Read-only.
Container — instanca image-a, running process.
Dockerfile — instrukcije kako build-at image.
docker-compose.yml — definira multi-container app (web + DB + Redis + queue).
Volume — persistentni storage izvan containera.
Network — virtualna mreža za container-to-container komunikaciju.
Registry — gdje se images čuvaju (Docker Hub, GitHub Container Registry, self-host).

Zašto koristit Docker

Reproducibilni dev environment — svi developeri pokreću identičnu PHP/Node/MySQL verziju. Nema "meni radi".
Onboarding novih developera — git clone && docker-compose up, gotovo. Ne treba 4h za setup XAMPP-a.
Više projekata, različite PHP verzije — projekt A na PHP 8.1, projekt B na PHP 8.3. Bez konflikta.
Production parity — dev container isti kao production container. Manje surprise bugova.
Microservices — svaki service u svom container-u, neovisan deploy.
CI/CD — GitHub Actions, GitLab CI, Drone — sve native koristi Docker.

Praktičan setup — Laravel projekt

Dockerfile

FROM php:8.2-fpm-alpine

RUN apk add --no-cache \
    libpng-dev libzip-dev mysql-client \
    && docker-php-ext-install pdo_mysql gd zip bcmath

COPY --from=composer:latest /usr/bin/composer /usr/bin/composer

WORKDIR /var/www

COPY . .

RUN composer install --no-dev --optimize-autoloader

CMD ["php-fpm"]

docker-compose.yml

version: '3.8'

services:
  app:
    build: .
    volumes:
      - .:/var/www
    depends_on: [db, redis]
    environment:
      DB_HOST: db
      REDIS_HOST: redis

  nginx:
    image: nginx:alpine
    ports: ['8080:80']
    volumes:
      - .:/var/www
      - ./nginx.conf:/etc/nginx/conf.d/default.conf
    depends_on: [app]

  db:
    image: mariadb:11
    environment:
      MYSQL_DATABASE: laravel
      MYSQL_ROOT_PASSWORD: secret
    volumes:
      - dbdata:/var/lib/mysql

  redis:
    image: redis:alpine

volumes:
  dbdata:

Pokretanje

docker-compose up -d
docker-compose exec app php artisan migrate
docker-compose exec app php artisan key:generate

Sajt na http://localhost:8080. Stop: docker-compose down.

Laravel Sail — Docker za lijene

Laravel Sail = service provider koji uključuje Docker u Laravel projekt s jednom komandom. Skripta ./vendor/bin/sail wraps docker-compose:

composer require laravel/sail --dev
php artisan sail:install
./vendor/bin/sail up -d
./vendor/bin/sail artisan migrate

Idealno za quick start novih projekata.

DDEV — Docker za Drupal/WP/Craft

DDEV je opinionated Docker wrapper za CMS development. Setup novog Craft projekta u 5 minuta:

ddev config --project-type=craftcms
ddev start
ddev composer install
ddev craft install

Plus: pre-konfigurirani PHP/MySQL/nginx, mkcert za HTTPS, mailhog za email testing, phpMyAdmin.

Volumes — persistentni podaci

Bind mount (.:/var/www) — direktorij na host-u mountan u container. Promjene odmah vidljive. Idealno za dev.
Named volume (dbdata:) — Docker upravlja storage-om. Idealno za baze.
Anonymous volume — kreira se ad-hoc. Briše se kad container ode.

Networks

Containers u istom docker-compose dijele default network. Pristupaju se po service name (npr. db, redis) kao DNS.

Custom networks za isolation:

networks:
  frontend:
  backend:

services:
  app:
    networks: [frontend, backend]
  db:
    networks: [backend]  # db nije dostupan iz frontend

Docker u produkciji

Dev container je jedna stvar, produkcija druga. Pitanja:

Orchestration: single-server (docker-compose), Docker Swarm (basic), Kubernetes (full).
Image registry: Docker Hub (public), GitHub Container Registry, GitLab Registry, self-hosted Harbor.
Secrets management: Docker Secrets (Swarm) ili Vault.
Logging: driver loki, json-file s rotation, Datadog agent.
Monitoring: Prometheus exporter na containerima.
Zero-downtime deploy: Swarm rolling update, K8s deployments, blue-green s nginx upstream switch.

Production-grade Dockerfile patterns

Multi-stage build

FROM node:20-alpine AS frontend-build
WORKDIR /app
COPY package*.json ./
RUN npm ci
COPY . .
RUN npm run build

FROM php:8.2-fpm-alpine
WORKDIR /var/www
COPY composer.* ./
RUN composer install --no-dev
COPY . .
COPY --from=frontend-build /app/public/build ./public/build

Final image samo PHP runtime + built assets. Bez Node, bez source-a frontend buildovaog.

Non-root user

RUN addgroup -g 1000 app && adduser -G app -u 1000 -D app
USER app

Security: container ne radi kao root.

.dockerignore

.git
node_modules
vendor
storage/logs/*
.env
.env.example

Sprječava da local dev fajlovi završe u image-u.

Common pitfalls

Image size: default PHP image je ~400MB. Alpine variant ~60MB. Multi-stage smanjuje još.
File permissions: container UID vs host UID se ne slažu, write problemi. Postavi UID/GID match.
Slow on macOS: bind mounts su sporiji na macOS-u. Koristi :cached ili :delegated, ili dev v Mutagen.
Stale cache: kad mijenjaš Dockerfile, ali Docker koristi cache. docker-compose build --no-cache.
Containers ne stop-aju: docker-compose down -v za clean reset (briše i volumes).
Port konflikt: port 80 zauzet od Apache/MySQL na host-u. Map drugi port (8080:80).

Docker Compose alternativa — Podman

Podman je rootless Docker alternativa od Red Hat-a. Compatible s docker CLI i compose. Sigurniji default, bolja izolacija. Za Linux production sve popularniji.

Kada NE koristit Docker

Jednostavan statički sajt — overkill.
Brzo razvijaš PHP skriptu lokalno bez DB-a — XAMPP/MAMP brži.
Hosting koji ne podržava Docker (većina shared) — postavi production na bare metal.
Tim koji ne zna Docker — learning curve troši vrijeme. Bolji direktan deploy ako tim je mali.

Docker hosting

VPS s Docker-om: najjeftinije, full kontrola.
Managed container hosting: AWS ECS, Google Cloud Run, Fly.io, Railway, Render.
Kubernetes managed: GKE, EKS, DigitalOcean Kubernetes, OVH Managed.
Self-hosted K8s: kompleksno, samo za ozbiljne use case.

WMD i Docker hosting

WMD nudi Docker-ready VPS i dedicated servere s pre-instaliranim Docker + Docker Compose. Postavljamo CI/CD pipeline (GitHub Actions ili Gitea Actions) da automatski build i deploy na server pri push-u. Image registry self-host (Harbor ili Gitea Container Registry). Backup volumes uključen u JetBackup. Za enterprise klijente s K8s potrebama, savjetujemo i konfiguriramo managed Kubernetes ili self-hosted (k3s, RKE2). Local DDEV ili Laravel Sail setup za novi WP/Craft/Laravel projekt uključen u onboarding.

FAQ

Docker ili Vagrant? Docker — moderniji, lakši, brži. Vagrant je manje popularno za novi projekt.

Docker Desktop alternativa za macOS/Windows? Rancher Desktop, OrbStack (macOS), Podman Desktop. Sve free i bolje od Docker Desktop u nekim aspektima.

Mogu li imat Docker container s GUI app? Tehnički da (X11 forwarding), praktički bolje nativni install.

Kubernetes je vrijedan za moj projekt? Ako imaš 50+ servisa ili masivnu skalu — da. Ako imaš jedan WP + DB + Redis — overkill.

Image size matter-a? Da — manji image = brži pull = brži deploy. Alpine + multi-stage = mali images.

Trebaš Docker setup za projekt ili production deploy? WMD postavlja Docker dev environment + CI/CD + production server. Javi se preko kontakt forme.

Korisni linkovi

Docker za web developere 2026 — praktičan vodič za PHP, Node, Craft, Laravel projekte