# Referensi Cepat Docker

*Container, image, volume, jaringan, compose*

> Source: Docker Documentation (docs.docker.com) · MIT

## Dasar

### Menjalankan Container

```
docker run nginx              # run image
docker run -d nginx           # detached (background)
docker run -p 8080:80 nginx   # map port
docker run --name web nginx   # named container
docker run -it ubuntu bash    # interactive shell
```

### Perintah Utama

| Command | Description |
|---------|-------------|
| `docker ps` | Tampilkan container yang berjalan |
| `docker ps -a` | Tampilkan semua container (termasuk yang berhenti) |
| `docker images` | Tampilkan image lokal |
| `docker pull nginx` | Unduh image dari registry |
| `docker info` | Informasi sistem secara keseluruhan |

## Manajemen Container

### Siklus Hidup

| Command | Description |
|---------|-------------|
| `docker start <id>` | Mulai container yang berhenti |
| `docker stop <id>` | Hentikan dengan baik (SIGTERM) |
| `docker kill <id>` | Paksa berhenti (SIGKILL) |
| `docker restart <id>` | Restart container |
| `docker rm <id>` | Hapus container yang berhenti |
| `docker rm -f <id>` | Paksa hapus (meskipun berjalan) |

### Inspeksi & Debugging

| Command | Description |
|---------|-------------|
| `docker logs <id>` | Lihat log container |
| `docker logs -f <id>` | Ikuti log (live) |
| `docker exec -it <id> bash` | Masuk shell container yang berjalan |
| `docker inspect <id>` | Metadata detail container (JSON) |
| `docker top <id>` | Proses yang berjalan di container |
| `docker stats` | Penggunaan resource secara live |

### Menyalin File

```
docker cp file.txt <id>:/app/    # host → container
docker cp <id>:/app/log.txt ./   # container → host
```

## Image

### Build & Tagging

```
docker build -t myapp .          # build from Dockerfile
docker build -t myapp:v2 .       # with tag
docker tag myapp user/myapp:v2   # retag image
```

### Publish

```
docker login
docker push user/myapp:v2
docker pull user/myapp:v2
```

### Manajemen Image

| Command | Description |
|---------|-------------|
| `docker images` | Tampilkan semua image lokal |
| `docker rmi <image>` | Hapus image |
| `docker image prune` | Hapus image yang tidak terpakai (dangling) |
| `docker system prune` | Hapus semua data yang tidak digunakan |
| `docker history <image>` | Tampilkan riwayat layer image |

## Dockerfile

### Instruksi Umum

| Command | Description |
|---------|-------------|
| `FROM node:20` | Image dasar |
| `WORKDIR /app` | Atur direktori kerja |
| `COPY . .` | Salin file ke image |
| `RUN npm install` | Jalankan perintah saat build |
| `CMD ["node", "app.js"]` | Perintah default saat runtime |
| `EXPOSE 3000` | Dokumentasikan port yang didengarkan |
| `ENV NODE_ENV=production` | Atur environment variable |
| `ARG VERSION=latest` | Variabel saat build |
| `ENTRYPOINT ["python"]` | Executable tetap (CMD = argumen) |

### Contoh Dockerfile

```
FROM node:20-alpine
WORKDIR /app
COPY package*.json ./
RUN npm ci --production
COPY . .
EXPOSE 3000
CMD ["node", "server.js"]
```

## Volume

### Penyimpanan Persisten

```
docker volume create mydata
docker run -v mydata:/app/data nginx
docker run -v $(pwd):/app nginx  # bind mount
```

### Perintah Volume

| Command | Description |
|---------|-------------|
| `docker volume ls` | Tampilkan volume |
| `docker volume inspect <v>` | Detail volume |
| `docker volume rm <v>` | Hapus volume |
| `docker volume prune` | Hapus volume yang tidak terpakai |

## Jaringan

### Dasar Jaringan

```
docker network create mynet
docker run --network mynet --name api nginx
docker run --network mynet --name db postgres
```

### Perintah Jaringan

| Command | Description |
|---------|-------------|
| `docker network ls` | Tampilkan jaringan |
| `docker network inspect <n>` | Detail jaringan |
| `docker network connect <n> <c>` | Hubungkan container ke jaringan |
| `docker network rm <n>` | Hapus jaringan |

*Container dalam jaringan yang sama dapat saling menjangkau berdasarkan nama*

## Docker Compose

### Contoh compose.yaml

```
services:
  web:
    build: .
    ports: ["3000:3000"]
    depends_on: [db]
  db:
    image: postgres:16
    environment:
      POSTGRES_PASSWORD: secret
    volumes: [pgdata:/var/lib/postgresql/data]
volumes:
  pgdata:
```

### Perintah Compose

| Command | Description |
|---------|-------------|
| `docker compose up` | Mulai semua service |
| `docker compose up -d` | Mulai di background |
| `docker compose down` | Hentikan dan hapus container |
| `docker compose down -v` | Juga hapus volume |
| `docker compose build` | Rebuild image |
| `docker compose logs -f` | Ikuti log semua service |
| `docker compose ps` | Tampilkan service yang berjalan |
| `docker compose exec web bash` | Masuk shell ke sebuah service |

## Pola Berguna

### Perintah Pembersihan

```
docker system prune -a          # remove all unused
docker container prune           # remove stopped
docker image prune -a            # remove unused images
```

### Resep Cepat

| Command | Description |
|---------|-------------|
| `Container sementara` | `docker run --rm -it alpine sh` |
| `Cek port` | `docker port <id>` |
| `Env var` | `docker run -e KEY=val image` |
| `Env file` | `docker run --env-file .env image` |
| `Restart policy` | `docker run --restart unless-stopped image` |
| `Batas resource` | `docker run --memory 512m --cpus 1 image` |