Fix for bool vs string comparisons in salt templates

cluster/saltbase/salt/kubelet/default

@@ -29,7 +29,7 @@
 
 {% set cluster_dns = "" %}
 {% set cluster_domain = "" %}
-{% if pillar['enable_cluster_dns'] is defined and pillar['enable_cluster_dns'] %}
+{% if pillar.get('enable_cluster_dns', '').lower() == 'true' %}
   {% set cluster_dns = "--cluster_dns=" + pillar['dns_server'] %}
   {% set cluster_domain = "--cluster_domain=" + pillar['dns_domain'] %}
 {% endif %}

cluster/saltbase/salt/top.sls

@@ -8,10 +8,10 @@ base:
     - docker
     - kubelet
     - kube-proxy
-{% if pillar['enable_node_monitoring'] is defined and pillar['enable_node_monitoring'] %}
+{% if pillar.get('enable_node_monitoring', '').lower() == 'true' %}
     - cadvisor
 {% endif %}
-{% if pillar['enable_node_logging'] is defined and pillar['enable_node_logging'] %}
+{% if pillar.get('enable_node_logging', '').lower() == 'true' %}
   {% if pillar['logging_destination'] is defined and pillar['logging_destination'] == 'elasticsearch' %}
     - fluentd-es
   {% endif %}