added 2 jinja filters: yaml and json

Author: Xavier Barbosa

doc/ref/renderers/all/salt.renderers.jinja.rst

@@ -99,6 +99,33 @@ the context into the included file is required:
 
 .. _imports: http://jinja.pocoo.org/docs/templates/#import
 
+Variable Serializers
+====================
+
+Salt allows to serialize any variable into **json** or **yaml**. For example this
+variable::
+
+    data:
+      foo: True
+      bar: 42
+      baz:
+        - 1
+        - 2
+        - 3
+      qux: 2.0
+
+with this template::
+
+    yaml -> {{ data|yaml }}
+
+    json -> {{ data|json }}
+
+will be rendered has::
+
+    yaml -> {bar: 42, baz: [1, 2, 3], foo: true, qux: 2.0}
+
+    json -> {"baz": [1, 2, 3], "foo": true, "bar": 42, "qux": 2.0}
+
 Template Inheritance
 ====================
 

salt/utils/jinja.py

@@ -5,17 +5,24 @@
 # Import python libs
 from os import path
 import logging
+from functools import partial
+import json
 
 # Import third party libs
-from jinja2 import BaseLoader
-from jinja2.exceptions import TemplateNotFound
+from jinja2 import BaseLoader, Markup, TemplateNotFound
+from jinja2.ext import Extension
+import yaml
 
 # Import salt libs
 import salt
 import salt.fileclient
 
 log = logging.getLogger(__name__)
 
+__all__ = [
+    'SaltCacheLoader',
+    'SerializerExtension'
+]
 
 class SaltCacheLoader(BaseLoader):
     '''
@@ -88,3 +95,45 @@ def uptodate():
                 continue
         # there is no template file within searchpaths
         raise TemplateNotFound(template)
+
+
+class SerializerExtension(Extension):
+    """
+    Serializes variables.
+
+    For example, this dataset:
+
+    .. code-block:: python
+
+        data = {
+            "foo": True,
+            "bar": 42,
+            "baz": [1, 2, 3],
+            "qux": 2.0
+        }
+
+    .. code-block:: jinja
+
+        yaml = {{ data|yaml }}
+        json = {{ data|json }}
+
+    will be rendered has::
+
+        yaml = {bar: 42, baz: [1, 2, 3], foo: true, qux: 2.0}
+        json = {"baz": [1, 2, 3], "foo": true, "bar": 42, "qux": 2.0}
+
+    """
+
+    def __init__(self, environment):
+        self.environment = environment
+        environment.filters.update({
+            'yaml': partial(self.format, formatter='yaml'),
+            'json': partial(self.format, formatter='json')
+        })
+
+    def format(self, value, formatter, *args, **kwargs):
+        if formatter == "json":
+            return Markup(json.dumps(value))
+        elif formatter == "yaml":
+            return Markup(yaml.dump(value, default_flow_style=True))
+        raise ValueError("Serializer {} is not implemented".format(formatter))

salt/utils/templates.py

@@ -21,6 +21,7 @@
 import salt.utils
 import salt.exceptions
 from salt.utils.jinja import SaltCacheLoader as JinjaSaltCacheLoader
+from salt.utils.jinja import SerializerExtension as JinjaSerializerExtension
 
 log = logging.getLogger(__name__)
 
@@ -107,6 +108,7 @@ def render_jinja_tmpl(tmplstr, context, tmplpath=None):
         env_args['extensions'].append('jinja2.ext.do')
     if hasattr(jinja2.ext, 'loopcontrols'):
         env_args['extensions'].append('jinja2.ext.loopcontrols')
+    jinja_env.add_extension(JinjaSerializerExtension)
 
     if opts.get('allow_undefined', False):
         jinja_env = jinja2.Environment(**env_args)