Custom Domains

func (c *Config) IsDomainAllowed(domain string) bool {
    for _, d := range c.Domains {
        if strings.EqualFold(d, domain) {
            return true
        }
    }
    return false
}

req.Domain = strings.ToLower(req.Domain)
if !h.Cfg.IsDomainAllowed(req.Domain) {
    jsonError(w, "domain not allowed", http.StatusBadRequest)
    return
}

DUBLY_DOMAINS="short.example.com,go.myapp.com,link.mybrand.io"

domainsRaw := os.Getenv("DUBLY_DOMAINS")
if domainsRaw == "" {
    return nil, fmt.Errorf("DUBLY_DOMAINS is required")
}
var domains []string
for _, d := range strings.Split(domainsRaw, ",") {
    d = strings.TrimSpace(d)
    if d != "" {
        domains = append(domains, d)
    }
}

sudo bash scripts/add-domain.sh short.example.com

# Validate domain contains no spaces
if [[ "$DOMAIN" == *" "* ]]; then
  error "Domain cannot contain spaces."
  exit 1
fi

# Validate domain has at least one dot
if [[ "$DOMAIN" != *.* ]]; then
  error "Domain must contain at least one dot (e.g. short.example.com)."
  exit 1
fi

CURRENT_DOMAINS="$(grep '^DUBLY_DOMAINS=' "$ENV_FILE" | cut -d= -f2-)"

IFS=',' read -ra DOMAIN_LIST <<< "$CURRENT_DOMAINS"
for d in "${DOMAIN_LIST[@]}"; do
  d="$(echo "$d" | xargs)"
  if [ "$d" = "$DOMAIN" ]; then
    error "Domain '$DOMAIN' is already in DUBLY_DOMAINS."
    exit 1
  fi
done

info "Adding $DOMAIN to $ENV_FILE..."
sed -i "s|^DUBLY_DOMAINS=.*|&,$DOMAIN|" "$ENV_FILE"
ok "Updated DUBLY_DOMAINS in $ENV_FILE"

short.example.com go.myapp.com {
    reverse_proxy localhost:8080
    encode gzip
}

if [ ! -f "$CADDYFILE" ]; then
  warn "No Caddyfile found at $CADDYFILE — skipping Caddy update."
  warn "You will need to add the domain to your Caddyfile manually."
else
  info "Adding $DOMAIN to $CADDYFILE..."
  # Prepend the new domain to the first non-comment line
  sed -i "0,/^[^#].*{/s|{|$DOMAIN {|" "$CADDYFILE"
  ok "Updated $CADDYFILE"
fi

server {
    listen 80;
    server_name short.example.com go.myapp.com link.mybrand.io;

    location / {
        proxy_pass http://localhost:8080;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    }
}

<VirtualHost *:80>
    ServerName short.example.com
    ServerAlias go.myapp.com link.mybrand.io

    ProxyPreserveHost On
    ProxyPass / http://localhost:8080/
    ProxyPassReverse / http://localhost:8080/
</VirtualHost>

host := r.Host
// Strip port if present
if h, _, err := net.SplitHostPort(host); err == nil {
    host = h
}
host = strings.ToLower(host)

func SlugExists(db *sql.DB, slug, domain string) (bool, error) {
    var count int
    err := db.QueryRow(
        `SELECT COUNT(*) FROM links WHERE slug = ? AND domain = ?`,
        slug, domain,
    ).Scan(&count)
    return count > 0, err
}