diff --git a/.gitignore b/.gitignore
index 8014359..be486dc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,10 +1,22 @@
 down/*
 !down/download.sh
 !down/offline_images
+
+# k8s binaries directory
 bin/*
 !bin/readme.md
+
+# kube-dns controller
 manifests/kubedns/kubedns.yaml
 manifests/coredns/coredns.yaml
+
+# ansible hosts
 hosts
+
+# k8s backup directory
 roles/cluster-backup/files/*
 !roles/cluster-backup/files/readme.md
+
+# roles/xxx/vars, exclude roles/os-harden/vars/
+/roles/*/vars/*
+!/roles/os-harden/vars/
diff --git a/roles/cluster-addon/defaults/main.yml b/roles/cluster-addon/defaults/main.yml
index e34ab75..40e7ab0 100644
--- a/roles/cluster-addon/defaults/main.yml
+++ b/roles/cluster-addon/defaults/main.yml
@@ -3,6 +3,11 @@ dns_install: "yes"
 dns_backend: "coredns"
 kubedns_offline: "kubedns_1.14.10.tar"
 coredns_offline: "coredns_1.1.3.tar"
+dns_offline: "{%- if dns_backend == 'coredns' -%} \
+                {{ coredns_offline }} \
+              {%- else -%} \
+                {{ kubedns_offline }} \
+              {%- endif -%}"
 
 # metric server 自动安装
 metricsserver_install: "yes"
diff --git a/roles/cluster-addon/vars/main.yml b/roles/cluster-addon/vars/main.yml
deleted file mode 100644
index 76d7617..0000000
--- a/roles/cluster-addon/vars/main.yml
+++ /dev/null
@@ -1,6 +0,0 @@
-dns_offline: "{%- if dns_backend == 'coredns' -%} \
-                {{ coredns_offline }} \
-              {%- else -%} \
-                {{ kubedns_offline }} \
-              {%- endif -%}"
-