add pillar_safe_render_error config

allow a salt admin to config if the detailed render error of pillars
can be passed to the minion.

conf/master

@@ -526,6 +526,12 @@
 # master config file that can then be used on minions.
 #pillar_opts: False
 
+# The pillar_safe_render_error option prevents the master from passing piller 
+# render errors to the minion. This is set on by default because the error could
+# contain templating data which would give that minion information it shouldn't
+# have, like a password! When set true the error message will only show:
+#   Rendering SLS 'my.sls' failed. Please see master log for details.
+#pillar_safe_render_error: True
 
 #####          Syndic settings       #####
 ##########################################

doc/topics/pillar/index.rst

@@ -374,4 +374,25 @@ to ``False``:
 
 .. code-block:: yaml
 
-    pillar_opts: False
+    pillar_opts: False
+
+
+Master Provided Pillar Error
+============================
+
+By default if there is an error rendering a pillar, the detailed error is
+hidden and replaced with:
+
+.. code-block:: bash
+
+    Rendering SLS 'my.sls' failed. Please see master log for details.
+
+The error is protected because it's possible to contain templating data
+which would give that minion information it shouldn't know, like a password!
+
+To have the master provide the detailed error that could potentially carry
+protected data set ``pillar_safe_render_error`` to ``False``:
+
+.. code-block:: yaml
+
+    pillar_safe_render_error: True

salt/config.py

@@ -190,6 +190,7 @@ VALID_OPTS = {
     'ext_pillar': list,
     'pillar_version': int,
     'pillar_opts': bool,
+    'pillar_safe_render_error': bool,
     'pillar_source_merging_strategy': str,
     'ping_on_rotate': bool,
     'peer': dict,
@@ -493,6 +494,7 @@ DEFAULT_MASTER_OPTS = {
     'ext_pillar': [],
     'pillar_version': 2,
     'pillar_opts': False,
+    'pillar_safe_render_error': True,
     'pillar_source_merging_strategy': 'smart',
     'ping_on_rotate': False,
     'peer': {},

salt/pillar/__init__.py

@@ -387,7 +387,10 @@ class Pillar(object):
                 sls, exc
             )
             log.critical(msg)
-            errors.append('Rendering SLS \'{0}\' failed. Please see master log for details.'.format(sls))
+            if self.opts.get('pillar_safe_render_error', True):
+                errors.append('Rendering SLS \'{0}\' failed. Please see master log for details.'.format(sls))
+            else:
+                errors.append(msg)
         mods.add(sls)
         nstate = None
         if state: