feat(feature-flag): Redis Feature Flag 灰度发布基础设施

Redis Feature Flag 灰度发布基础设施：白名单+百分比切流+全局开关，热更新，内部管理API

apps/api/app/api/router.py

@@ -8,6 +8,7 @@ from app.api.routes.dashboard import router as dashboard_router
 from app.api.routes.duplication import router as duplication_router
 from app.api.routes.edit_plans import router as edit_plans_router
 from app.api.routes.edit_templates import router as edit_templates_router
+from app.api.routes.feature_flags import router as feature_flags_router
 from app.api.routes.generated_videos import router as generated_videos_router
 from app.api.routes.generation_tasks import router as generation_tasks_router
 from app.api.routes.health import router as health_check_router
@@ -151,3 +152,7 @@ api_router.include_router(
     prefix="/tts",
     tags=["TTS"],
 )
+api_router.include_router(
+    feature_flags_router,
+    tags=["Internal"],
+)

apps/api/app/api/routes/feature_flags.py

@@ -0,0 +1,195 @@
+"""Feature Flag 内部管理接口。
+
+通过内部 API Key 鉴权，支持查看和修改 Feature Flag 配置。
+主要用于灰度发布期间的动态开关控制。
+
+API:
+  GET  /api/v1/internal/feature-flags          - 列出所有 flag
+  GET  /api/v1/internal/feature-flags/{name}   - 查看单个 flag
+  PUT  /api/v1/internal/feature-flags/{name}   - 设置 flag 配置
+  DELETE /api/v1/internal/feature-flags/{name} - 删除 flag
+
+鉴权：X-API-Key header，走内部 API Key 验证
+"""
+
+from __future__ import annotations
+
+import logging
+from typing import Optional
+
+from app.api.routes.auth import _verify_internal_api_key
+from app.config import settings
+from fastapi import APIRouter, Depends, HTTPException, Query, status
+from pydantic import BaseModel, Field
+
+from packages.adapters.redis.feature_flag_store import (
+    FEATURE_FLAG_REDIS_PREFIX,
+    FeatureFlagConfig,
+    RedisFeatureFlagStore,
+)
+
+logger = logging.getLogger(__name__)
+
+router = APIRouter(prefix="/internal/feature-flags", tags=["Internal"])
+
+# 允许管理的 flag 白名单（防止误操作其他系统 flag）
+ALLOWED_FLAGS = {
+    "render_engine",
+}
+
+
+def _get_feature_flag_store() -> RedisFeatureFlagStore:
+    """获取 Feature Flag 存储实例。"""
+    return RedisFeatureFlagStore(redis_url=settings.REDIS_URL)
+
+
+class FeatureFlagUpdateRequest(BaseModel):
+    """Feature Flag 更新请求体。"""
+
+    enabled: bool = Field(..., description="是否启用")
+    percentage: int = Field(0, ge=0, le=100, description="灰度百分比 (0-100)")
+    whitelist: list[str] = Field(default_factory=list, description="白名单列表（如 user_id）")
+
+
+class FeatureFlagResponse(BaseModel):
+    """Feature Flag 响应。"""
+
+    name: str
+    enabled: bool
+    percentage: int
+    whitelist: list[str]
+
+    @classmethod
+    def from_config(cls, config: FeatureFlagConfig) -> "FeatureFlagResponse":
+        return cls(
+            name=config.name,
+            enabled=config.enabled,
+            percentage=config.percentage,
+            whitelist=sorted(config.whitelist),
+        )
+
+
+class FeatureFlagCheckResponse(BaseModel):
+    """Flag 激活检查响应。"""
+
+    name: str
+    active: bool
+    identifier: Optional[str] = None
+
+
+def _validate_flag_name(name: str) -> None:
+    """校验 flag 名称是否在允许列表中。"""
+    if name not in ALLOWED_FLAGS:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail=f"Unsupported flag: {name}. Allowed: {sorted(ALLOWED_FLAGS)}",
+        )
+
+
+@router.get("", response_model=list[FeatureFlagResponse])
+async def list_feature_flags(
+    _: bool = Depends(_verify_internal_api_key),
+    store: RedisFeatureFlagStore = Depends(_get_feature_flag_store),
+):
+    """列出所有 Feature Flag。"""
+    try:
+        flags = store.list_all()
+        # 同时返回预定义的 flag（即使未设置也显示默认值）
+        result = []
+        for name in sorted(ALLOWED_FLAGS):
+            config = flags.get(name) or FeatureFlagConfig(name=name, enabled=False)
+            result.append(FeatureFlagResponse.from_config(config))
+        # 加上已存在但不在白名单中的 flag（只读展示）
+        for name, config in flags.items():
+            if name not in ALLOWED_FLAGS:
+                result.append(FeatureFlagResponse.from_config(config))
+        return sorted(result, key=lambda x: x.name)
+    except Exception as exc:
+        logger.error("Failed to list feature flags: %s", exc)
+        raise HTTPException(status_code=500, detail=f"Failed to list flags: {exc}")
+
+
+@router.get("/{name}", response_model=FeatureFlagResponse)
+async def get_feature_flag(
+    name: str,
+    _: bool = Depends(_verify_internal_api_key),
+    store: RedisFeatureFlagStore = Depends(_get_feature_flag_store),
+):
+    """获取单个 Feature Flag 配置。"""
+    try:
+        config = store.get(name)
+        return FeatureFlagResponse.from_config(config)
+    except Exception as exc:
+        logger.error("Failed to get feature flag %s: %s", name, exc)
+        raise HTTPException(status_code=500, detail=f"Failed to get flag: {exc}")
+
+
+@router.get("/{name}/check", response_model=FeatureFlagCheckResponse)
+async def check_feature_flag(
+    name: str,
+    identifier: Optional[str] = Query(None, description="标识符，如 user_id"),
+    _: bool = Depends(_verify_internal_api_key),
+    store: RedisFeatureFlagStore = Depends(_get_feature_flag_store),
+):
+    """检查某个标识符是否命中 Feature Flag。"""
+    try:
+        active = store.is_active(name, identifier=identifier)
+        return FeatureFlagCheckResponse(name=name, active=active, identifier=identifier)
+    except Exception as exc:
+        logger.error("Failed to check feature flag %s: %s", name, exc)
+        raise HTTPException(status_code=500, detail=f"Failed to check flag: {exc}")
+
+
+@router.put("/{name}", response_model=FeatureFlagResponse)
+async def update_feature_flag(
+    name: str,
+    request: FeatureFlagUpdateRequest,
+    _: bool = Depends(_verify_internal_api_key),
+    store: RedisFeatureFlagStore = Depends(_get_feature_flag_store),
+):
+    """更新 Feature Flag 配置。
+
+    只允许修改 ALLOWED_FLAGS 列表中的 flag。
+    """
+    _validate_flag_name(name)
+
+    try:
+        config = FeatureFlagConfig(
+            name=name,
+            enabled=request.enabled,
+            percentage=request.percentage,
+            whitelist=set(request.whitelist),
+        )
+        store.set(config)
+        logger.info(
+            "Feature flag updated: name=%s enabled=%s percentage=%d whitelist=%d",
+            name,
+            config.enabled,
+            config.percentage,
+            len(config.whitelist),
+        )
+        return FeatureFlagResponse.from_config(config)
+    except Exception as exc:
+        logger.error("Failed to update feature flag %s: %s", name, exc)
+        raise HTTPException(status_code=500, detail=f"Failed to update flag: {exc}")
+
+
+@router.delete("/{name}", status_code=status.HTTP_204_NO_CONTENT)
+async def delete_feature_flag(
+    name: str,
+    _: bool = Depends(_verify_internal_api_key),
+    store: RedisFeatureFlagStore = Depends(_get_feature_flag_store),
+):
+    """删除 Feature Flag。
+
+    只允许删除 ALLOWED_FLAGS 列表中的 flag。
+    """
+    _validate_flag_name(name)
+
+    try:
+        deleted = store.delete(name)
+        logger.info("Feature flag deleted: name=%s deleted=%s", name, deleted)
+        return None
+    except Exception as exc:
+        logger.error("Failed to delete feature flag %s: %s", name, exc)
+        raise HTTPException(status_code=500, detail=f"Failed to delete flag: {exc}")