feat(tracing): 集成 OpenTelemetry 链路追踪功能

- 在 base.py 中添加文件下载、上传和 FFmpeg 执行的链路追踪
- 在 api_client.py 中实现 API 请求的链路追踪和错误标记
- 在 lease_service.py 中添加租约续期的链路追踪支持
- 在 task_executor.py 中集成任务执行的完整链路追踪
- 新增 util/tracing.py 工具模块提供统一的追踪上下文管理
- 在 .env.example 中添加 OTEL 配置选项
- 在 index.py 中初始化和关闭链路追踪功能

services/lease_service.py

@@ -8,10 +8,13 @@
 import logging
 import threading
 import time
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, Any, Optional
 
 if TYPE_CHECKING:
     from services.api_client import APIClientV2
+    from util.tracing import TaskTraceContext
+
+from util.tracing import bind_trace_context, start_span
 
 logger = logging.getLogger(__name__)
 
@@ -29,7 +32,9 @@ class LeaseService:
         api_client: 'APIClientV2',
         task_id: str,
         interval: int = 60,
-        extension: int = 300
+        extension: int = 300,
+        parent_otel_context: Any = None,
+        task_trace_context: Optional['TaskTraceContext'] = None,
     ):
         """
         初始化租约服务
@@ -44,6 +49,8 @@ class LeaseService:
         self.task_id = task_id
         self.interval = interval
         self.extension = extension
+        self.parent_otel_context = parent_otel_context
+        self.task_trace_context = task_trace_context
         self.running = False
         self.thread: threading.Thread = None
         self._stop_event = threading.Event()
@@ -79,25 +86,29 @@ class LeaseService:
 
     def _run(self):
         """续期线程主循环"""
-        while self.running:
-            # 等待指定间隔或收到停止信号
-            if self._stop_event.wait(timeout=self.interval):
-                # 收到停止信号
-                break
+        with bind_trace_context(self.parent_otel_context, self.task_trace_context):
+            while self.running:
+                if self._stop_event.wait(timeout=self.interval):
+                    break
 
-            if self.running:
-                self._extend_lease()
+                if self.running:
+                    self._extend_lease()
 
     def _extend_lease(self):
         """执行租约续期"""
-        try:
-            success = self.api_client.extend_lease(self.task_id, self.extension)
-            if success:
-                logger.debug(f"[task:{self.task_id}] Lease extended by {self.extension}s")
-            else:
-                logger.warning(f"[task:{self.task_id}] Failed to extend lease")
-        except Exception as e:
-            logger.warning(f"[task:{self.task_id}] Lease extension error: {e}")
+        with start_span(
+            "render.task.lease.extend",
+            task_id=self.task_id,
+            attributes={"render.lease.extension_seconds": self.extension},
+        ):
+            try:
+                success = self.api_client.extend_lease(self.task_id, self.extension)
+                if success:
+                    logger.debug(f"[task:{self.task_id}] Lease extended by {self.extension}s")
+                else:
+                    logger.warning(f"[task:{self.task_id}] Failed to extend lease")
+            except Exception as e:
+                logger.warning(f"[task:{self.task_id}] Lease extension error: {e}")
 
     def __enter__(self):
         """上下文管理器入口"""