Update 'dns_warmup/dns_warmup.sh'

dns_warmup/dns_warmup.sh

@@ -1,2 +1,14 @@
 #!/bin/bash
 
+target_domain=$1
+if [[ -z "${target_domain}" ]]; then
+    echo "target_domain should not be null. Usage: ./${0} <target_domain>"
+    exit 1
+fi
+
+while true;
+do
+  date
+  cat chinese_public_dns.list | grep -v '#' | grep '.' | xargs -I {} dig +time=15 +tries=1 @{} ${target_domain} > /dev/null 2>&1
+  sleep 60
+done