fix: improve type annotations and etcd header extraction

- Add proper type annotations to _get_etcd_stats return type and stats variable
- Extract header field from v3 API response for cluster_id and member_id
- Update comment to clarify header extraction purpose

Signed-off-by: Keiven Chang <[email protected]>

Author: keivenchang

deploy/dynamo_check.py

@@ -918,13 +918,13 @@ def _get_etcd_info(self, host: str, port: int) -> Optional[dict]:
             pass
         return None
 
-    def _get_etcd_stats(self, host: str, port: int) -> Optional[dict]:
+    def _get_etcd_stats(self, host: str, port: int) -> Optional[Dict[str, Any]]:
         """Get etcd statistics including uptime and member info."""
         try:
             import json
             import urllib.request
 
-            stats = {}
+            stats: Dict[str, Any] = {}
 
             # Try to get leader stats for uptime
             try:
@@ -959,7 +959,7 @@ def _get_etcd_stats(self, host: str, port: int) -> Optional[dict]:
             except Exception:
                 pass
 
-            # Try to get cluster member information
+            # Try to get cluster member information and header (cluster_id)
             try:
                 members_url = f"http://{host}:{port}/v2/members"
                 req = urllib.request.Request(members_url)
@@ -968,7 +968,6 @@ def _get_etcd_stats(self, host: str, port: int) -> Optional[dict]:
                     if "members" in members_data:
                         stats["members"] = len(members_data["members"])
             except Exception:
-                # Try v3 API for members
                 try:
                     members_url = f"http://{host}:{port}/v3/cluster/member/list"
                     data: dict[str, str] = {}
@@ -981,6 +980,8 @@ def _get_etcd_stats(self, host: str, port: int) -> Optional[dict]:
                         members_data = json.loads(response.read().decode())
                         if "members" in members_data:
                             stats["members"] = len(members_data["members"])
+                        if "header" in members_data:
+                            stats["header"] = members_data["header"]
                 except Exception:
                     pass