diff --git a/cluster-update b/cluster-update
index a9bf588..92d7cca 100644
--- a/cluster-update
+++ b/cluster-update
@@ -1 +1,13 @@
 #!/bin/bash
+WORKER_LIST="worker.list"
+apt update
+apt upgrade -y
+for LINE in $(cat $WORKER_LIST | grep -vE "^#"); do
+	WORKERNAME=`echo $LINE | awk -F"/" '{print $NF}'`
+
+	echo "[worker:$WORKERNAME] Updating..."
+	ssh $WORKERNAME -o "StrictHostKeyChecking no" "bash -s" < apt update
+  ssh $WORKERNAME -o "StrictHostKeyChecking no" "bash -s" < apt upgrade -y
+
+	echo "[worker:$WORKERNAME] Update is completed."
+done