istio-external-auth-观察.md

+### 问题
 
-## background
-
-https://istio.io/latest/blog/2021/better-external-authz/
-
-> ![image](https://istio.io/latest/blog/2021/better-external-authz/external_authz.svg)
-
-remark: well-written
+想明白平台中的 external auth
 
 ### related files
 
@@ -41,6 +36,15 @@ spec:
         paths: ["/api/v1*"]
 ```
 
+## background
+
+https://istio.io/latest/blog/2021/better-external-authz/
+
+> ![image](https://istio.io/latest/blog/2021/better-external-authz/external_authz.svg)
+
+remark: well-written
+
+Cluster Discovery Service.
 
 
 https://www.envoyproxy.io/docs/envoy/latest/intro/arch_overview/security/ext_authz_filter#arch-overview-ext-authz