Hack to make rendering work on CentOS 6

!!   Not tested with an actual   !!
 !!  configured `ext_pillar` yet  !!

- jinja on RHEL/CentOS 6 has no 'mapping'
  test (see salt-formula issue #193)
- {% do ... %} allows no assignment, only
  function calls
- of course, `type(foo) is dict` doesn't
  work because it's no jinja test
- maybe `.isinstance()` would be nicer/more
  reliable

salt/files/master.d/f_defaults.conf

@@ -960,17 +960,22 @@ pillar_roots:
 
 {% if 'ext_pillar' in cfg_master %}
 {%- do default_keys.append('ext_pillar') %}
+{#- workaround for missing mapping test in CentOS 6, part A #}
+{%- set is_mapping = {} %}
 ext_pillar:
 {%- for pillar in cfg_master['ext_pillar'] -%}
   {%- for key in pillar -%}
     {%- if pillar[key] is string %}
   - {{ key }}: {{ pillar[key] }}
-    {%- elif pillar[key] is iterable and pillar[key] is not mapping %}
+    {#- workaround for missing mapping test in CentOS 6, part B #}
+    {%- do is_mapping.update({key: type(pillar[key]) == type({})}) %}
+    {%- elif pillar[key] is iterable and not is_mapping[key] %}
   - {{ key }}:
       {%- for parameter in pillar[key] %}
     - {{ parameter }}
       {%- endfor -%}
-    {%- elif pillar[key] is mapping and pillar[key] is not string %}
+    {#- workaround for missing mapping test in CentOS 6, part C #}
+    {%- elif is_mapping[key] and pillar[key] is not string %}
   - {{ key }}: 
       {%- for parameter in pillar[key] %}
       {{ parameter }}: {{pillar[key][parameter]}}