WAF & Shield----->Web ACLs---->Add rules----->Add managed rules group--->Add managed rule groups--->Bot control--->打开 add to web ACL---->Edit--->
Version:默认
Bot Control inspection level:common
Scope of inspection:Inspect all web requests
Bot Control rules：
Override all rule actions：Override to count
Common:
SignalNonBrowserUserAgent:Override to block
点击save rules保存---》Add rules---save
https://repost.aws/zh-Hans/knowledge-center/waf-block-http-requests-no-user-agent
自定义：
WAF & Shield----->Web ACLs---->Add rules----->
type:Regular rule
If a request:doesn't match the statement (NoT)
Inspect:Single header
Header field name:user-agent
Size greater than
Size in bytes:0
action:block
