1~
2Binago ng Docker ang paraan ng pagbuo, pagpapadala, at pagpapatakbo natin ng software. Sa halip na "gumagana sa makina ko," ginagarantiya ng Docker na pareho ang takbo ng iyong application kahit saan - sa iyong laptop, sa makina ng katrabaho, sa CI/CD, at sa production. Sa gabay na ito, magsisimula tayo mula sa zero hanggang sa pag-deploy ng isang tunay na application.
3~
4## Ano ang Docker?
5~
6Ang Docker ay isang platform na nagpa-package ng iyong application at lahat ng dependencies nito sa isang standardized unit na tinatawag na **container**. Ang container ay isang isolated, magaan na proseso na nagbabahagi ng host OS kernel ngunit may sariling filesystem, network, at process space.
7~
8```mermaid
9graph TD
10    subgraph "Traditional Deployment"
11        A1[App 1] --> OS1[Guest OS]
12        A2[App 2] --> OS2[Guest OS]
13        OS1 --> HV[Hypervisor]
14        OS2 --> HV
15        HV --> HW1[Hardware]
16    end
17~
18    subgraph "Docker Deployment"
19        B1[App 1] --> D1[Container]
20        B2[App 2] --> D2[Container]
21        D1 --> DE[Docker Engine]
22        D2 --> DE
23        DE --> HW2[Hardware]
24    end
25```
26~
27### Mga Container vs Virtual Machine
28~
29| Aspeto | Mga Container | Virtual Machine |
30|--------|-------------|-----------------|
31| **Startup** | Segundo | Minuto |
32| **Laki** | MB | GB |
33| **OS** | Nagbabahagi ng host kernel | Buong guest OS |
34| **Isolation** | Antas ng proseso | Antas ng hardware |
35| **Performance** | Halos native | Overhead mula sa hypervisor |
36| **Density** | Daan-daan bawat host | Sampu-sampu bawat host |
37~
38## Pag-install ng Docker
39~
40```bash
41# macOS
42brew install --cask docker
43~
44# Ubuntu/Debian
45curl -fsSL https://get.docker.com | sh
46sudo usermod -aG docker $USER
47~
48# Verify installation
49docker --version
50docker run hello-world
51```
52~
53## Mga Pangunahing Konsepto
54~
55### Mga Image
56~
57Ang image ay isang read-only template na may mga tagubilin para sa paggawa ng container. Isipin ito bilang isang snapshot ng iyong application at ng kapaligiran nito.
58~
59```bash
60# Pull an image from Docker Hub
61docker pull node:20-alpine
62~
63# List local images
64docker images
65~
66# Remove an image
67docker rmi node:20-alpine
68```
69~
70### Mga Container
71~
72Ang container ay isang tumatakbo na instance ng isang image. Maaari kang gumawa, mag-start, mag-stop, at mag-delete ng mga container.
73~
74```bash
75# Run a container
76docker run -d --name my-app -p 3000:3000 node:20-alpine
77~
78# List running containers
79docker ps
80~
81# List all containers (including stopped)
82docker ps -a
83~
84# Stop a container
85docker stop my-app
86~
87# Remove a container
88docker rm my-app
89~
90# View logs
91docker logs my-app
92~
93# Execute a command inside a running container
94docker exec -it my-app sh
95```
96~
97## Pagsulat ng Dockerfile
98~
99Ang Dockerfile ay isang text file na may mga tagubilin para sa pagbuo ng image. Bawat tagubilin ay gumagawa ng isang layer.
100~
101### Basic na Dockerfile para sa isang Node.js App
102~
103```dockerfile
104# Use an official Node.js runtime as base image
105FROM node:20-alpine
106~
107# Set working directory
108WORKDIR /app
109~
110# Copy package files first (better caching)
111COPY package.json package-lock.json ./
112~
113# Install dependencies
114RUN npm ci --only=production
115~
116# Copy application code
117COPY . .
118~
119# Expose the port the app runs on
120EXPOSE 3000
121~
122# Command to run the application
123CMD ["node", "server.js"]
124```
125~
126### Pagbuo at Pagpapatakbo
127~
128```bash
129# Build the image
130docker build -t my-node-app .
131~
132# Run the container
133docker run -d -p 3000:3000 my-node-app
134~
135# Visit http://localhost:3000
136```
137~
138## Multi-Stage Build
139~
140Ang mga multi-stage build ay nagpapanatiling maliit ng iyong production image sa pamamagitan ng paghihiwalay ng build environment mula sa runtime.
141~
142```dockerfile
143# Stage 1: Build
144FROM node:20-alpine AS builder
145WORKDIR /app
146COPY package.json package-lock.json ./
147RUN npm ci
148COPY . .
149RUN npm run build
150~
151# Stage 2: Production
152FROM node:20-alpine AS runner
153WORKDIR /app
154COPY --from=builder /app/dist ./dist
155COPY --from=builder /app/node_modules ./node_modules
156COPY --from=builder /app/package.json ./
157EXPOSE 3000
158CMD ["node", "dist/server.js"]
159```
160~
161Gumagawa ito ng image na naglalaman lamang ng compiled output at production dependencies - walang source code, walang dev dependencies, walang build tools.
162~
163### Next.js Multi-Stage Halimbawa
164~
165```dockerfile
166FROM node:20-alpine AS deps
167WORKDIR /app
168COPY package.json package-lock.json ./
169RUN npm ci
170~
171FROM node:20-alpine AS builder
172WORKDIR /app
173COPY --from=deps /app/node_modules ./node_modules
174COPY . .
175RUN npm run build
176~
177FROM node:20-alpine AS runner
178WORKDIR /app
179ENV NODE_ENV=production
180COPY --from=builder /app/public ./public
181COPY --from=builder /app/.next/standalone ./
182COPY --from=builder /app/.next/static ./.next/static
183EXPOSE 3000
184CMD ["node", "server.js"]
185```
186~
187## Mga Volume: Persistent na Data
188~
189Bilang default, nawawala ang data sa loob ng container kapag inalis ang container. Nilulutas ito ng mga volume.
190~
191```bash
192# Create a named volume
193docker volume create my-data
194~
195# Run with a volume
196docker run -d -v my-data:/app/data my-app
197~
198# Bind mount (map host directory to container)
199docker run -d -v $(pwd)/data:/app/data my-app
200~
201# List volumes
202docker volume ls
203```
204~
205## Networking
206~
207Gumagawa ang Docker ng mga isolated network para makipag-usap ang mga container.
208~
209```bash
210# Create a custom network
211docker network create my-network
212~
213# Run containers on the same network
214docker run -d --name api --network my-network my-api
215docker run -d --name db --network my-network postgres:16
216~
217# Containers can reach each other by name
218# From "api" container: postgres://db:5432
219```
220~
221```mermaid
222graph LR
223    subgraph "my-network"
224        API[api container\nport 3000] -- "db:5432" --> DB[db container\nport 5432]
225    end
226    User -- "localhost:3000" --> API
227```
228~
229## Docker Compose
230~
231Hinahayaan ka ng Docker Compose na i-define at patakbuhin ang mga multi-container application gamit ang isang YAML file.
232~
233### docker-compose.yml
234~
235```yaml
236services:
237  api:
238    build: ./api
239    ports:
240      - "3000:3000"
241    environment:
242      - DATABASE_URL=postgres://user:pass@db:5432/mydb
243    depends_on:
244      - db
245~
246  db:
247    image: postgres:16-alpine
248    environment:
249      - POSTGRES_USER=user
250      - POSTGRES_PASSWORD=pass
251      - POSTGRES_DB=mydb
252    volumes:
253      - pgdata:/var/lib/postgresql/data
254    ports:
255      - "5432:5432"
256~
257  redis:
258    image: redis:7-alpine
259    ports:
260      - "6379:6379"
261~
262volumes:
263  pgdata:
264```
265~
266### Mga Command
267~
268```bash
269# Start all services
270docker compose up -d
271~
272# View logs
273docker compose logs -f
274~
275# Stop all services
276docker compose down
277~
278# Rebuild and restart
279docker compose up -d --build
280~
281# Scale a service
282docker compose up -d --scale api=3
283```
284~
285## .dockerignore
286~
287Tulad ng `.gitignore`, pinipigilan ng file na ito ang mga hindi kailangang file na makopya sa image.
288~
289```plaintext
290node_modules
291.git
292.env
293*.md
294.next
295dist
296coverage
297```
298~
299## Mga Pinakamahuhusay na Kasanayan para sa Production
300~
301### 1. Gumamit ng Maliliit na Base Image
302~
303```dockerfile
304# Bad: 1GB+
305FROM node:20
306~
307# Good: ~180MB
308FROM node:20-alpine
309```
310~
311### 2. Huwag Patakbuhin bilang Root
312~
313```dockerfile
314FROM node:20-alpine
315RUN addgroup -S app && adduser -S app -G app
316USER app
317WORKDIR /home/app
318COPY --chown=app:app . .
319```
320~
321### 3. Gumamit ng Specific na Image Tag
322~
323```dockerfile
324# Bad: can change unexpectedly
325FROM node:latest
326~
327# Good: pinned version
328FROM node:20.11-alpine3.19
329```
330~
331### 4. Samantalahin ang Build Cache
332~
333Ayusin ang mga tagubilin ng iyong Dockerfile mula sa pinakamadalang hanggang sa pinakamadalas na nagbabago:
334~
335```dockerfile
336FROM node:20-alpine
337WORKDIR /app
338~
339# These change rarely - cached
340COPY package.json package-lock.json ./
341RUN npm ci --only=production
342~
343# This changes often - not cached
344COPY . .
345```
346~
347### 5. Health Check
348~
349```dockerfile
350HEALTHCHECK --interval=30s --timeout=3s --retries=3 \
351  CMD wget -qO- http://localhost:3000/health || exit 1
352```
353~
354### 6. Gumamit ng Environment Variable
355~
356```dockerfile
357ENV NODE_ENV=production
358ENV PORT=3000
359```
360~
361## Cheat Sheet ng mga Karaniwang Docker Command
362~
363```bash
364# Images
365docker build -t name:tag .        # Build image
366docker images                      # List images
367docker rmi image_name              # Remove image
368docker image prune                 # Remove unused images
369~
370# Containers
371docker run -d -p 3000:3000 image   # Run detached
372docker ps                          # List running
373docker stop container_name         # Stop
374docker rm container_name           # Remove
375docker logs -f container_name      # Follow logs
376docker exec -it container sh       # Shell into container
377~
378# Compose
379docker compose up -d               # Start services
380docker compose down                # Stop services
381docker compose logs -f             # Follow all logs
382docker compose ps                  # List services
383~
384# Cleanup
385docker system prune -a             # Remove everything unused
386```
387~
388## Mula Docker Papuntang Kubernetes
389~
390Pinangangasiwaan ng Docker ang mga indibidwal na container. Kapag kailangan mong i-orchestrate ang daan-daang container sa maraming server, kailangan mo ng Kubernetes. Nagpupunan ang Docker at Kubernetes:
391~
3921. **Docker**: nagbubuo at nagpapatakbo ng mga container
3932. **Kubernetes**: nag-o-orchestrate ng mga container sa malaking sukat (scheduling, scaling, healing)
394~
395Kung interesado ka sa susunod na hakbang, tingnan ang aking artikulo tungkol sa Introduction to Kubernetes.
396~
397## Konklusyon
398~
399Ang Docker ay isang pundamental na kasanayan para sa mga modernong developer. Inaalis nito ang mga hindi pagkakatugma ng kapaligiran, pinapasimple ang deployment, at pundasyon ito ng container orchestration gamit ang Kubernetes. Magsimula sa isang simpleng Dockerfile, lumipat sa Docker Compose para sa mga multi-service app, at i-adopt ang multi-stage build at security best practice habang lumalaki ka.
400~
401Ang pinakamahusay na paraan para matuto ng Docker ay i-containerize ang isang proyekto na ginagawa mo na. Magsimula ngayon.
402~