# Referensi Cepat Nginx

*Server block, proxy, SSL, load balancing, logging*

> Source: Nginx Documentation (nginx.org/en/docs) · MIT

## Instalasi

### Instalasi per OS

| Command | Description |
|---------|-------------|
| `Ubuntu / Debian` | `sudo apt install nginx` |
| `RHEL / CentOS` | `sudo dnf install nginx` |
| `macOS` | `brew install nginx` |
| `Alpine` | `apk add nginx` |
| `Docker` | `docker run -p 80:80 nginx` |

### Manajemen Layanan

| Command | Description |
|---------|-------------|
| `sudo systemctl start nginx` | Mulai Nginx |
| `sudo systemctl stop nginx` | Hentikan Nginx |
| `sudo systemctl reload nginx` | Muat ulang konfigurasi (tanpa downtime) |
| `sudo systemctl enable nginx` | Aktifkan saat booting |
| `nginx -t` | Uji sintaks konfigurasi |
| `nginx -T` | Uji dan tampilkan konfigurasi lengkap |
| `nginx -s reload` | Kirim sinyal reload ke proses yang berjalan |

## Konfigurasi Dasar

### Lokasi File

| Command | Description |
|---------|-------------|
| `/etc/nginx/nginx.conf` | File konfigurasi utama |
| `/etc/nginx/conf.d/` | Konfigurasi site tambahan (*.conf) |
| `/etc/nginx/sites-available/` | Konfigurasi site tersedia (Debian) |
| `/etc/nginx/sites-enabled/` | Symlink ke konfigurasi aktif |
| `/var/log/nginx/` | Log akses dan error |
| `/var/www/html/` | Document root default |

### Konfigurasi Minimal

```
server {
    listen 80;
    server_name example.com;
    root /var/www/mysite;
    index index.html;
}
```

### Struktur Konfigurasi

| Command | Description |
|---------|-------------|
| `http { }` | Pengaturan server HTTP (level teratas) |
| `server { }` | Definisi virtual host |
| `location { }` | Blok pencocokan URI |
| `upstream { }` | Grup server backend |
| `events { }` | Pengaturan penanganan koneksi |

## Server Block

### Virtual Host Berbasis Nama

```
server {
    listen 80;
    server_name site-a.com;
    root /var/www/site-a;
}
server {
    listen 80;
    server_name site-b.com;
    root /var/www/site-b;
}
```

### Default & Catch-All

```
server {
    listen 80 default_server;
    server_name _;
    return 444;  # putus koneksi
}
```

### Redirect ke HTTPS

```
server {
    listen 80;
    server_name example.com;
    return 301 https://$host$request_uri;
}
```

## Location Block

### Prioritas Pencocokan (tinggi ke rendah)

| Command | Description |
|---------|-------------|
| `= /path` | Pencocokan tepat (prioritas tertinggi) |
| `^~ /path` | Pencocokan prefix, lewati regex |
| `~ regex` | Regex case-sensitive |
| `~* regex` | Regex case-insensitive |
| `/path` | Pencocokan prefix (prioritas terendah) |

### Contoh Location

```
location = / {
    # hanya root tepat
}
location /api/ {
    proxy_pass http://backend;
}
location ~* \.(jpg|png|gif)$ {
    expires 30d;
}
```

### try_files

```
location / {
    try_files $uri $uri/ /index.html;
}
```

*Coba file, direktori, lalu fallback -- penting untuk SPA*

## Reverse Proxy

### Proxy Dasar

```
location /api/ {
    proxy_pass http://localhost:3000/;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto $scheme;
}
```

### Proxy WebSocket

```
location /ws/ {
    proxy_pass http://localhost:3000;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "upgrade";
}
```

### Direktif Proxy

| Command | Description |
|---------|-------------|
| `proxy_pass` | URL backend |
| `proxy_set_header` | Teruskan header kustom ke backend |
| `proxy_read_timeout` | Timeout respons backend (default 60s) |
| `proxy_buffering off` | Nonaktifkan buffering respons |
| `proxy_redirect` | Tulis ulang header Location dari backend |

## SSL / TLS

### Server HTTPS

```
server {
    listen 443 ssl;
    server_name example.com;

    ssl_certificate     /etc/ssl/certs/example.crt;
    ssl_certificate_key /etc/ssl/private/example.key;
    ssl_protocols       TLSv1.2 TLSv1.3;
    ssl_ciphers         HIGH:!aNULL:!MD5;
}
```

### Let's Encrypt dengan Certbot

```
sudo certbot --nginx -d example.com
sudo certbot renew --dry-run
```

### Best Practice SSL

| Command | Description |
|---------|-------------|
| `ssl_protocols TLSv1.2 TLSv1.3` | Nonaktifkan versi TLS lama |
| `ssl_prefer_server_ciphers on` | Server memilih cipher |
| `ssl_session_cache shared:SSL:10m` | Reuse sesi untuk performa |
| `add_header Strict-Transport-Security` | Header HSTS |
| `ssl_stapling on` | OCSP stapling untuk handshake lebih cepat |

## Load Balancing

### Blok Upstream

```
upstream backend {
    server 10.0.0.1:3000;
    server 10.0.0.2:3000;
    server 10.0.0.3:3000;
}
server {
    location / {
        proxy_pass http://backend;
    }
}
```

### Metode Load Balancing

| Command | Description |
|---------|-------------|
| `(default)` | Round-robin |
| `least_conn` | Koneksi aktif paling sedikit |
| `ip_hash` | Sesi sticky berdasarkan IP client |
| `hash $request_uri` | Hash konsisten berdasarkan URI |

### Opsi Server

| Command | Description |
|---------|-------------|
| `weight=3` | Kirim 3x lebih banyak traffic |
| `max_fails=3` | Kegagalan sebelum ditandai mati |
| `fail_timeout=30s` | Waktu menandai server sebagai mati |
| `backup` | Gunakan hanya jika server lain mati |
| `down` | Tandai server sebagai offline permanen |

## File Statis & Caching

### Sajikan File Statis

```
location /static/ {
    alias /var/www/assets/;
    expires 30d;
    add_header Cache-Control "public, immutable";
}
```

### Kompresi Gzip

```
gzip on;
gzip_types text/plain text/css
           application/json application/javascript;
gzip_min_length 1000;
gzip_comp_level 5;
```

### Direktif Caching

| Command | Description |
|---------|-------------|
| `expires 30d` | Set header Expires dan Cache-Control max-age |
| `expires off` | Nonaktifkan header expires |
| `etag on` | Aktifkan header ETag (default) |
| `sendfile on` | Penyajian file efisien via kernel |
| `tcp_nopush on` | Optimalkan pengiriman paket |

## Logging

### Konfigurasi Log

```
access_log /var/log/nginx/access.log;
error_log  /var/log/nginx/error.log warn;

# Format log kustom
log_format main '$remote_addr - $status '
                '"$request" $body_bytes_sent';
access_log /var/log/nginx/access.log main;
```

### Level Log Error

| Command | Description |
|---------|-------------|
| `debug` | Verbose (perlu --with-debug) |
| `info` | Informasional |
| `notice` | Normal tapi perlu diperhatikan |
| `warn` | Peringatan |
| `error` | Error (default) |
| `crit` | Masalah kritis |

### Logging Kondisional

```
map $status $loggable {
    ~^[23] 0;
    default 1;
}
access_log /var/log/nginx/access.log combined if=$loggable;
```

*Lewati logging respons 2xx/3xx untuk mengurangi volume log*

## Keamanan

### Rate Limiting

```
limit_req_zone $binary_remote_addr
    zone=api:10m rate=10r/s;

location /api/ {
    limit_req zone=api burst=20 nodelay;
}
```

### Kontrol Akses

```
location /admin/ {
    allow 192.168.1.0/24;
    deny all;
}
```

### Header Keamanan

| Command | Description |
|---------|-------------|
| `X-Frame-Options DENY` | Cegah clickjacking |
| `X-Content-Type-Options nosniff` | Cegah MIME sniffing |
| `X-XSS-Protection "1; mode=block"` | Filter XSS (browser lama) |
| `Content-Security-Policy` | Kontrol sumber pemuatan resource |
| `Referrer-Policy no-referrer` | Kontrol informasi referrer |

## Pola Umum

### SPA (Single-Page App)

```
location / {
    root /var/www/app;
    try_files $uri $uri/ /index.html;
}
```

### Header CORS

```
location /api/ {
    add_header Access-Control-Allow-Origin *;
    add_header Access-Control-Allow-Methods
               "GET, POST, PUT, DELETE, OPTIONS";
    if ($request_method = OPTIONS) {
        return 204;
    }
    proxy_pass http://backend;
}
```

### Variabel Berguna

| Command | Description |
|---------|-------------|
| `$host` | Header Host request |
| `$uri` | URI saat ini (ternormalisasi) |
| `$request_uri` | URI asli dengan query string |
| `$remote_addr` | Alamat IP client |
| `$scheme` | http atau https |
| `$args` | Parameter query string |
| `$status` | Kode status respons |