feat: per-domain backend routing

Each allowed_domains entry can now carry its own backend {host, port}.
That lets one proxy on port 25565 serve multiple MC servers, picking
the upstream from the domain the client typed.

- proxy/main.py: ProxyState.backend_for(domain) → tuple|None,
  honors per-domain backend first, falls back to top-level backend.
  handle_client uses backend_for(); blocked / disabled domains
  return None (and still get a Login Disconnect on join attempts).
- api/routes/{config,domains}.py: DomainBackend model + optional
  backend field on create/patch. PATCH supports clear_backend=true
  to drop a per-domain override and revert to default.
- frontend/Domains.jsx: full rewrite — new-domain form has host/port
  inputs, table shows each row's effective backend, inline edit +
  reset button per row.
- frontend/Settings.jsx: backend section relabeled "기본 백엔드 (fallback)"
- README updated with multi-server example config.

README.md

@@ -10,6 +10,7 @@
 - 허용 도메인 화이트리스트 매칭, 불일치 시 Login Disconnect 패킷으로 차단 사유(커스텀 가능) 표시 후 연결 종료
 - 통과한 연결은 백엔드 MC 서버로 투명 TCP 중계
   (Fabric / Paper / Spigot / NeoForge 등 서버 종류 무관)
+- **도메인별 백엔드 라우팅**: 도메인마다 다른 IP:포트로 보낼 수 있어 하나의 25565 포트로 여러 MC 서버를 동시에 운영 가능 (예: `mc.tkrmagid.kr` → 게임PC:25565, `creative.tkrmagid.kr` → NAS:25566)
 - 설정 파일(`data/config.json`) 변경을 프록시가 자동 감지해 hot reload (재시작 불필요)
 - 모든 연결 시도(허용 / 차단 / 에러)를 SQLite 에 기록
 - 웹 대시보드 (NPM 스타일): 도메인 관리, 실시간 로그, 통계 카드, 백엔드/포트 설정
@@ -43,13 +44,18 @@ mc-filter-proxy 컨테이너 (25565)
    {
      "proxy":   { "listen_port": 25565, "enabled": true },
      "backend": { "host": "192.168.0.20", "port": 25565 },
+     "block_message": "이 서버는 허용된 도메인에서만 접속 가능합니다.",
      "allowed_domains": [
-       { "domain": "mc.tkrmagid.kr", "enabled": true, "note": "메인 도메인" }
+       { "domain": "mc.tkrmagid.kr", "enabled": true, "note": "메인 서버" },
+       { "domain": "creative.tkrmagid.kr", "enabled": true, "note": "크리에이티브",
+         "backend": { "host": "192.168.0.21", "port": 25566 } }
      ]
    }
    EOF
    ```
 
+   각 도메인 entry 에 `backend` 필드가 있으면 그 host:port 로, 없으면 top-level `backend` 로 라우팅됩니다.
+
 3. 전체 스택 빌드 & 실행
 
    ```bash

api/routes/config.py

@@ -19,10 +19,16 @@ class BackendConfig(BaseModel):
     port: int = Field(ge=1, le=65535)
 
 
+class DomainBackend(BaseModel):
+    host: str
+    port: int = Field(ge=1, le=65535)
+
+
 class DomainEntry(BaseModel):
     domain: str
     enabled: bool = True
     note: str = ""
+    backend: DomainBackend | None = None  # 없으면 top-level backend 로 fallback
 
 
 class FullConfig(BaseModel):

api/routes/domains.py

@@ -2,22 +2,32 @@
 from __future__ import annotations
 
 from fastapi import APIRouter, HTTPException, Response
-from pydantic import BaseModel
+from pydantic import BaseModel, Field
 
 from config_io import load_config, save_config
 
 router = APIRouter()
 
 
+class DomainBackend(BaseModel):
+    host: str
+    port: int = Field(ge=1, le=65535)
+
+
 class DomainCreate(BaseModel):
     domain: str
     enabled: bool = True
     note: str = ""
+    backend: DomainBackend | None = None  # 비우면 기본 backend 사용
 
 
 class DomainPatch(BaseModel):
     enabled: bool | None = None
     note: str | None = None
+    # 명시적으로 None 을 보내려면 클라이언트가 "backend": null 을 보내야 한다.
+    # 빠뜨리면 기존 값 유지.
+    backend: DomainBackend | None = None
+    clear_backend: bool = False  # True 면 기존 backend 삭제 → 기본값으로 복귀
 
 
 @router.get("/domains")
@@ -34,7 +44,9 @@ def add_domain(body: DomainCreate) -> dict:
         raise HTTPException(status_code=400, detail="domain required")
     if any(d["domain"].lower() == name for d in domains):
         raise HTTPException(status_code=409, detail="domain already exists")
-    entry = {"domain": name, "enabled": body.enabled, "note": body.note}
+    entry: dict = {"domain": name, "enabled": body.enabled, "note": body.note}
+    if body.backend is not None:
+        entry["backend"] = body.backend.model_dump()
     domains.append(entry)
     save_config(cfg)
     return entry
@@ -64,6 +76,10 @@ def patch_domain(domain: str, body: DomainPatch) -> dict:
                 d["enabled"] = body.enabled
             if body.note is not None:
                 d["note"] = body.note
+            if body.clear_backend:
+                d.pop("backend", None)
+            elif body.backend is not None:
+                d["backend"] = body.backend.model_dump()
             save_config(cfg)
             return d
     raise HTTPException(status_code=404, detail="domain not found")

frontend/src/pages/Domains.jsx

@@ -1,32 +1,42 @@
 import { useEffect, useState } from 'react'
 import { api } from '../api.js'
 
+const blankBackend = { host: '', port: '' }
+
 export default function Domains() {
   const [domains, setDomains] = useState([])
+  const [defaultBackend, setDefaultBackend] = useState(null)
   const [newDomain, setNewDomain] = useState('')
   const [newNote, setNewNote] = useState('')
+  const [newBackend, setNewBackend] = useState({ ...blankBackend })
   const [error, setError] = useState(null)
+  const [editing, setEditing] = useState(null) // {domain, host, port}
 
   async function load() {
     try {
-      setDomains(await api.domains())
+      const [doms, cfg] = await Promise.all([api.domains(), api.config()])
+      setDomains(doms)
+      setDefaultBackend(cfg.backend)
       setError(null)
     } catch (e) {
       setError(e.message)
     }
   }
 
-  useEffect(() => {
+  useEffect(() => { load() }, [])
-    load()
-  }, [])
 
   async function add(e) {
     e.preventDefault()
     if (!newDomain.trim()) return
     try {
-      await api.addDomain({ domain: newDomain.trim(), enabled: true, note: newNote })
+      const body = { domain: newDomain.trim(), enabled: true, note: newNote }
+      if (newBackend.host.trim() && newBackend.port) {
+        body.backend = { host: newBackend.host.trim(), port: +newBackend.port }
+      }
+      await api.addDomain(body)
       setNewDomain('')
       setNewNote('')
+      setNewBackend({ ...blankBackend })
       setError(null)
       await load()
     } catch (e) {
@@ -38,9 +48,7 @@ export default function Domains() {
     try {
       await api.patchDomain(d.domain, { enabled: !d.enabled })
       await load()
-    } catch (e) {
+    } catch (e) { setError(e.message) }
-      setError(e.message)
-    }
   }
 
   async function remove(d) {
@@ -48,66 +56,163 @@ export default function Domains() {
     try {
       await api.deleteDomain(d.domain)
       await load()
-    } catch (e) {
+    } catch (e) { setError(e.message) }
-      setError(e.message)
+  }
-    }
+
+  function startEdit(d) {
+    setEditing({
+      domain: d.domain,
+      host: d.backend?.host ?? '',
+      port: d.backend?.port ?? '',
+    })
+  }
+
+  async function saveEdit() {
+    try {
+      const { domain, host, port } = editing
+      if (!host.trim() || !port) {
+        // 둘 다 비우면 backend 삭제 → 기본값으로 폴백
+        await api.patchDomain(domain, { clear_backend: true })
+      } else {
+        await api.patchDomain(domain, {
+          backend: { host: host.trim(), port: +port },
+        })
+      }
+      setEditing(null)
+      await load()
+    } catch (e) { setError(e.message) }
+  }
+
+  async function clearBackend(d) {
+    if (!confirm(`${d.domain} 의 개별 backend 설정을 지우고 기본값으로 되돌릴까요?`)) return
+    try {
+      await api.patchDomain(d.domain, { clear_backend: true })
+      await load()
+    } catch (e) { setError(e.message) }
   }
 
   return (
     <div>
       <h1>허용 도메인</h1>
       {error && <div className="error">{error}</div>}
-      <form onSubmit={add} className="form-row card">
+
-        <input
+      <form onSubmit={add} className="card">
-          placeholder="mc.example.com"
+        <h2>새 도메인</h2>
-          value={newDomain}
+        <div className="form-grid">
-          onChange={(e) => setNewDomain(e.target.value)}
+          <label>
-        />
+            도메인
-        <input
+            <input
-          placeholder="메모 (선택)"
+              placeholder="mc.example.com"
-          value={newNote}
+              value={newDomain}
-          onChange={(e) => setNewNote(e.target.value)}
+              onChange={(e) => setNewDomain(e.target.value)}
-        />
+              required
-        <button type="submit">추가</button>
+            />
+          </label>
+          <label>
+            메모 (선택)
+            <input
+              placeholder="메인 서버, 모드팩 등"
+              value={newNote}
+              onChange={(e) => setNewNote(e.target.value)}
+            />
+          </label>
+          <label>
+            백엔드 호스트 (선택)
+            <input
+              placeholder={defaultBackend ? `기본값: ${defaultBackend.host}` : ''}
+              value={newBackend.host}
+              onChange={(e) => setNewBackend({ ...newBackend, host: e.target.value })}
+            />
+          </label>
+          <label>
+            백엔드 포트 (선택)
+            <input
+              type="number"
+              placeholder={defaultBackend ? `기본값: ${defaultBackend.port}` : ''}
+              value={newBackend.port}
+              onChange={(e) => setNewBackend({ ...newBackend, port: e.target.value })}
+            />
+          </label>
+        </div>
+        <div className="actions">
+          <button type="submit">추가</button>
+          <span className="muted">백엔드 호스트/포트를 비워두면 설정 페이지의 기본 backend 로 라우팅됩니다.</span>
+        </div>
       </form>
+
       <table className="table">
         <thead>
           <tr>
             <th>도메인</th>
             <th>메모</th>
+            <th>백엔드</th>
             <th style={{ width: 80 }}>활성</th>
-            <th style={{ width: 90 }}></th>
+            <th style={{ width: 200 }}></th>
           </tr>
         </thead>
         <tbody>
           {domains.length === 0 && (
             <tr>
-              <td colSpan={4} className="muted" style={{ textAlign: 'center', padding: 24 }}>
+              <td colSpan={5} className="muted" style={{ textAlign: 'center', padding: 24 }}>
                 등록된 도메인이 없습니다.
               </td>
             </tr>
           )}
-          {domains.map((d) => (
+          {domains.map((d) => {
-            <tr key={d.domain}>
+            const isEditing = editing?.domain === d.domain
-              <td>
+            return (
-                <code>{d.domain}</code>
+              <tr key={d.domain}>
-              </td>
+                <td><code>{d.domain}</code></td>
-              <td>{d.note}</td>
+                <td>{d.note}</td>
-              <td>
+                <td>
-                <label className="switch">
+                  {isEditing ? (
-                  <input
+                    <div className="inline-edit">
-                    type="checkbox"
+                      <input
-                    checked={d.enabled}
+                        placeholder="host"
-                    onChange={() => toggle(d)}
+                        value={editing.host}
-                  />
+                        onChange={(e) => setEditing({ ...editing, host: e.target.value })}
-                  <span />
+                      />
-                </label>
+                      <input
-              </td>
+                        type="number"
-              <td>
+                        placeholder="port"
-                <button className="danger" onClick={() => remove(d)}>삭제</button>
+                        value={editing.port}
-              </td>
+                        onChange={(e) => setEditing({ ...editing, port: e.target.value })}
-            </tr>
+                        style={{ width: 90 }}
-          ))}
+                      />
+                    </div>
+                  ) : d.backend ? (
+                    <code>{d.backend.host}:{d.backend.port}</code>
+                  ) : (
+                    <span className="muted">
+                      기본값 ({defaultBackend ? `${defaultBackend.host}:${defaultBackend.port}` : '-'})
+                    </span>
+                  )}
+                </td>
+                <td>
+                  <label className="switch">
+                    <input type="checkbox" checked={d.enabled} onChange={() => toggle(d)} />
+                    <span />
+                  </label>
+                </td>
+                <td>
+                  {isEditing ? (
+                    <>
+                      <button onClick={saveEdit}>저장</button>
+                      <button className="ghost" onClick={() => setEditing(null)} style={{ marginLeft: 4 }}>취소</button>
+                    </>
+                  ) : (
+                    <>
+                      <button className="ghost" onClick={() => startEdit(d)}>백엔드</button>
+                      {d.backend && (
+                        <button className="ghost" onClick={() => clearBackend(d)} style={{ marginLeft: 4 }}>초기화</button>
+                      )}
+                      <button className="danger" onClick={() => remove(d)} style={{ marginLeft: 4 }}>삭제</button>
+                    </>
+                  )}
+                </td>
+              </tr>
+            )
+          })}
         </tbody>
       </table>
     </div>

frontend/src/pages/Settings.jsx

@@ -69,7 +69,11 @@ export default function Settings() {
         </label>
       </section>
       <section className="card">
-        <h2>백엔드 (실제 MC 서버)</h2>
+        <h2>기본 백엔드 (도메인별 backend 가 없을 때 fallback)</h2>
+        <p className="muted" style={{ marginTop: 0 }}>
+          허용 도메인 페이지에서 각 도메인에 별도 backend (host:port) 를 지정할 수 있습니다.
+          지정하지 않은 도메인은 여기 값으로 라우팅됩니다.
+        </p>
         <label>
           호스트 (IP 또는 hostname)
           <input

frontend/src/styles.css

@@ -189,6 +189,22 @@ textarea:focus {
   align-items: center;
 }
 .form-row input { flex: 1; }
+.form-grid {
+  display: grid;
+  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
+  gap: 12px;
+  margin-bottom: 12px;
+}
+.form-grid label {
+  display: flex;
+  flex-direction: column;
+  gap: 4px;
+  color: var(--muted);
+  font-size: 12px;
+}
+.form-grid input { width: 100%; }
+.inline-edit { display: flex; gap: 6px; }
+.inline-edit input { padding: 4px 8px; font-size: 13px; }
 
 .table {
   width: 100%;

proxy/main.py

@@ -129,9 +129,31 @@ class ProxyState:
         return cfg_mod.allowed_domain_set(self.cfg)
 
     def backend(self) -> tuple[str, int]:
+        """기본 백엔드 (도메인 entry 에 backend 가 없을 때 fallback)."""
         b = self.cfg["backend"]
         return b["host"], int(b["port"])
 
+    def backend_for(self, domain: str) -> tuple[str, int] | None:
+        """주어진 도메인이 활성 화이트리스트에 있으면 라우팅 대상을 돌려준다.
+
+        도메인 entry 에 `backend.host`/`backend.port` 가 있으면 그 값을 우선,
+        없으면 top-level `backend` 로 fallback. 도메인이 비활성이거나 없으면
+        None.
+        """
+        d = domain.lower().strip()
+        for entry in self.cfg.get("allowed_domains", []):
+            if entry["domain"].lower().strip() != d:
+                continue
+            if not entry.get("enabled", True):
+                return None
+            be = entry.get("backend") or {}
+            host = (be.get("host") or "").strip()
+            port = be.get("port")
+            if host and port:
+                return host, int(port)
+            return self.backend()
+        return None
+
     def enabled(self) -> bool:
         return bool(self.cfg.get("proxy", {}).get("enabled", True))
 
@@ -212,8 +234,8 @@ async def handle_client(
         return
 
     domain = hs.server_address.lower().strip()
-    allowed = state.allowed()
+    target = state.backend_for(domain)
-    if domain not in allowed:
+    if target is None:
         log_event(client_ip, domain, hs.next_state, "blocked", "domain not allowed")
         log.info(
             "BLOCK %s domain=%r next_state=%d", client_ip, domain, hs.next_state
@@ -230,7 +252,7 @@ async def handle_client(
         client_writer.close()
         return
 
-    backend_host, backend_port = state.backend()
+    backend_host, backend_port = target
     try:
         backend_reader, backend_writer = await asyncio.wait_for(
             asyncio.open_connection(backend_host, backend_port), timeout=5