Merge pull request #25680 from basepi/jinja.alias.25049

[2015.5] Move cmd.run jinja aliasing to a wrapper class to prevent side effects

salt/utils/templates.py

@@ -41,6 +41,68 @@ TEMPLATE_DIRNAME = os.path.join(saltpath[0], 'templates')
 SLS_ENCODING = 'utf-8'  # this one has no BOM.
 SLS_ENCODER = codecs.getencoder(SLS_ENCODING)
 
+ALIAS_WARN = (
+        'Starting in 2015.5, cmd.run uses python_shell=False by default, '
+        'which doesn\'t support shellisms (pipes, env variables, etc). '
+        'cmd.run is currently aliased to cmd.shell to prevent breakage. '
+        'Please switch to cmd.shell or set python_shell=True to avoid '
+        'breakage in the future, when this aliasing is removed.'
+)
+ALIASES = {
+        'cmd.run': 'cmd.shell',
+        'cmd': {'run': 'shell'},
+}
+
+
+class AliasedLoader(object):
+    '''
+    Light wrapper around the LazyLoader to redirect 'cmd.run' calls to
+    'cmd.shell', for easy use of shellisms during templating calls
+
+    Dotted aliases ('cmd.run') must resolve to another dotted alias
+    (e.g. 'cmd.shell')
+
+    Non-dotted aliases ('cmd') must resolve to a dictionary of function
+    aliases for that module (e.g. {'run': 'shell'})
+    '''
+
+    def __init__(self, wrapped):
+        self.wrapped = wrapped
+
+    def __getitem__(self, name):
+        if name in ALIASES:
+            salt.utils.warn_until('Nitrogen', ALIAS_WARN)
+            return self.wrapped[ALIASES[name]]
+        else:
+            return self.wrapped[name]
+
+    def __getattr__(self, name):
+        if name in ALIASES:
+            salt.utils.warn_until('Nitrogen', ALIAS_WARN)
+            return AliasedModule(getattr(self.wrapped, name), ALIASES[name])
+        else:
+            return getattr(self.wrapped, name)
+
+
+class AliasedModule(object):
+    '''
+    Light wrapper around module objects returned by the LazyLoader's getattr
+    for the purposes of `salt.cmd.run()` syntax in templates
+
+    Allows for aliasing specific functions, such as `run` to `shell` for easy
+    use of shellisms during templating calls
+    '''
+    def __init__(self, wrapped, aliases):
+        self.aliases = aliases
+        self.wrapped = wrapped
+
+    def __getattr__(self, name):
+        if name in self.aliases:
+            salt.utils.warn_until('Nitrogen', ALIAS_WARN)
+            return getattr(self.wrapped, self.aliases[name])
+        else:
+            return getattr(self.wrapped, name)
+
 
 def wrap_tmpl_func(render_str):
 
@@ -57,11 +119,7 @@ def wrap_tmpl_func(render_str):
         # Alias cmd.run to cmd.shell to make python_shell=True the default for
         # templated calls
         if 'salt' in kws:
-            if 'cmd.run' in kws['salt'] and 'cmd.shell' in kws['salt']:
-                kws['salt']['cmd.run'] = kws['salt']['cmd.shell']
-            if 'run' in kws['salt'].get('cmd', {}) \
-                    and 'shell' in kws['salt'].get('cmd', {}):
-                kws['salt']['cmd']['run'] = kws['salt']['cmd']['shell']
+            kws['salt'] = AliasedLoader(kws['salt'])
 
         # We want explicit context to overwrite the **kws
         kws.update(context)

salt/version.py

@@ -83,7 +83,7 @@ class SaltStackVersion(object):
         'Beryllium'     : (MAX_SIZE - 105, 0),
         'Boron'         : (MAX_SIZE - 104, 0),
         'Carbon'        : (MAX_SIZE - 103, 0),
-        #'Nitrogen'     : (MAX_SIZE - 102, 0),
+        'Nitrogen'      : (MAX_SIZE - 102, 0),
         #'Oxygen'       : (MAX_SIZE - 101, 0),
         #'Fluorine'     : (MAX_SIZE - 100, 0),
         #'Neon'         : (MAX_SIZE - 99 , 0),