Merge pull request #14311 from sivel/unsafe-yaml-constructor

Add new 'unsafe' YAML constructor

docsite/rst/playbooks_advanced_syntax.rst

@@ -0,0 +1,59 @@
+Advanced Syntax
+===============
+
+.. contents:: Topics
+
+This page describes advanced YAML syntax that enables you to have more control over the data placed in YAML files used by Ansible.
+
+.. _yaml_tags_and_python_types
+
+YAML tags and Python types
+``````````````````````````
+
+The documentation covered here is an extension of the documentation that can be found in the `PyYAML Documentation <http://pyyaml.org/wiki/PyYAMLDocumentation#YAMLtagsandPythontypes>`_
+
+.. _unsafe_strings
+
+Unsafe or Raw Strings
+~~~~~~~~~~~~~~~~~~~~~
+
+As of Ansible 2.0, there is an internal data type for declaring variable values as "unsafe". This means that the data held within the variables value should be treated as unsafe preventing unsafe character subsitition and information disclosure.
+
+Jinja2 contains functionality for escaping, or telling Jinja2 to not template data by means of functionality such as ``{% raw %} ... {% endraw %}``, however this uses a more comprehensive implementation to ensure that the value is never templated.
+
+Using YAML tags, you can also mark a value as "unsafe" by using the ``!unsafe`` tag such as::
+
+    ---
+    my_unsafe_variable: !unsafe 'this variable has {{ characters that shouldn't be treated as a jinja2 template'
+
+In a playbook, this may look like::
+
+    ---
+    hosts: all
+    vars:
+        my_unsafe_variable: !unsafe 'unsafe value'
+    tasks:
+        ...
+
+For complex variables such as hashes or arrays, ``!unsafe`` should be used on the individual elements such as::
+
+    ---
+    my_unsafe_array:
+        - !unsafe 'unsafe element'
+        - 'safe element'
+
+    my_unsafe_hash:
+        unsafe_key: !unsafe 'unsafe value'
+
+ 
+
+.. seealso::
+
+   :doc:`playbooks_variables`
+       All about variables
+   `User Mailing List <http://groups.google.com/group/ansible-project>`_
+       Have a question?  Stop by the google group!
+   `irc.freenode.net <http://irc.freenode.net>`_
+       #ansible IRC chat channel
+
+

docsite/rst/playbooks_special_topics.rst

@@ -14,6 +14,7 @@ and adopt these only if they seem relevant or useful to your environment.
    playbooks_delegation
    playbooks_environment
    playbooks_error_handling
+   playbooks_advanced_syntax
    playbooks_lookups
    playbooks_prompts
    playbooks_tags

docsite/rst/playbooks_variables.rst

@@ -933,6 +933,11 @@ how all of these things can work together.
 .. _ansible-examples: https://github.com/ansible/ansible-examples
 .. _builtin filters: http://jinja.pocoo.org/docs/templates/#builtin-filters
 
+Advanced Syntax
+```````````````
+
+For information about advanced YAML syntax used to declare variables and have more control over the data placed in YAML files used by Ansible, see `playbooks_advanced_syntax`_
+
 .. seealso::
 
    :doc:`playbooks`

lib/ansible/parsing/yaml/constructor.py

@@ -22,6 +22,7 @@ __metaclass__ = type
 from yaml.constructor import Constructor, ConstructorError
 from yaml.nodes import MappingNode
 from ansible.parsing.yaml.objects import AnsibleMapping, AnsibleSequence, AnsibleUnicode
+from ansible.vars.unsafe_proxy import wrap_var
 
 try:
     from __main__ import display
@@ -72,7 +73,7 @@ class AnsibleConstructor(Constructor):
 
         return mapping
 
-    def construct_yaml_str(self, node):
+    def construct_yaml_str(self, node, unsafe=False):
         # Override the default string handling function
         # to always return unicode objects
         value = self.construct_scalar(node)
@@ -80,6 +81,9 @@ class AnsibleConstructor(Constructor):
 
         ret.ansible_pos = self._node_position_info(node)
 
+        if unsafe:
+            ret = wrap_var(ret)
+
         return ret
 
     def construct_yaml_seq(self, node):
@@ -88,6 +92,9 @@ class AnsibleConstructor(Constructor):
         data.extend(self.construct_sequence(node))
         data.ansible_pos = self._node_position_info(node)
 
+    def construct_yaml_unsafe(self, node):
+        return self.construct_yaml_str(node, unsafe=True)
+
     def _node_position_info(self, node):
         # the line number where the previous token has ended (plus empty lines)
         # Add one so that the first line is line 1 rather than line 0
@@ -121,3 +128,7 @@ AnsibleConstructor.add_constructor(
 AnsibleConstructor.add_constructor(
     u'tag:yaml.org,2002:seq',
     AnsibleConstructor.construct_yaml_seq)
+
+AnsibleConstructor.add_constructor(
+    u'!unsafe',
+    AnsibleConstructor.construct_yaml_unsafe)