Add extra_vars parsing directives due to Jinja

Jinja always casts extra_vars to string because it is impossible to
specify in a schema what vars might pass through extra_vars. So, to make
it possible to pass objects through Jinja and have them show up as
objects or ints or whatever, this adds directives with tests to show
they work.

The directives available are: '!INT', '!JSON', '!AST'. See the readme
for how to use them.

CHANGES.md

@@ -1,5 +1,22 @@
 # Changelog
 
+## v0.6.0
+
+* Add extra_vars parsing directives to get around difficulties with Jinja (which casts all
+  extra_vars as strings). When passing in an object via Jinja, all values become strings. To get
+  around this, add "!AST", "!JSON", or "!INT" directives in your action-chain yaml:
+
+```yaml
+chain:
+  name: 'example'
+  ref: 'ansible.command_local'
+  extra_parameters:
+    -
+      keyA: "!AST{{ jinja_variable_a }}"
+      keyB: "!JSON{{ jinja_variable_b | tojson }}"
+      keyC: "!INT{{ jinja_variable_c | int }}"
+```
+
 ## v0.5.0
 
 * Added ability to use yaml structures to pass arbitrarily complex values through extra_vars. key=value and @file syntax is still supported. Example usage:

README.md

@@ -72,6 +72,53 @@ sample_task:
           key8: value8
 ```
 
+##### Structured input and Jinja
+Note that `value3`, in the previous example, was passed in as a variable in a Jinja expression.
+StackStorm normally casts variables to the types like int, array, and object.
+However, it can't do that for extra_vars because we cannot know ahead of time,
+for all Ansible playbooks, what schema and data types each entry will be. As such,
+within extra_vars, all Jinja expressions result in strings. To get around this, we've
+added some extra_vars parsing diretives: `!INT`, `!JSON`, and `!AST`.
+
+Use `!INT` if you are using a playbook that expects a value to be an integer:
+
+```yaml
+extra_vars:
+  port: '!INT{{ port_number }}'
+```
+
+Use `!JSON` when you have something that is already a JSON string or when it makes sense
+to convert it into a json string using Jinja filters:
+
+```yaml
+extra_vars:
+  special_config: '!JSON{{ config | tojson }}'
+```
+
+Use `!AST` (referring to python AST) when you have an object that you want to send straight over
+without any additional jinja filters:
+
+```yaml
+extra_vars:
+  data: '!AST{{ data }}'
+```
+
+These directives are supported recursively. So, you can embed directives in other directives.
+Consider this contrived example (though mostly you'll only hit embedding directives or objects
+if you're chaining workflows together to build up a data object):
+
+```yaml
+vars:
+  answer: "!INT{{ life_universe_everything }}"
+chain:
+  -
+    name: '...'
+    ref: 'ansible.playbook'
+    ...
+    extra_vars:
+      earth: '!JSON{"question": "unknown", "answer": {{ answer }} }'
+```
+
 ##### Structured output
 ```sh
 # get structured JSON output from a playbook

actions/lib/ansible_base.py

@@ -1,6 +1,9 @@
 import os
 import sys
 import subprocess
+
+import yaml
+
 import shell
 import ast
 import json
@@ -27,6 +30,24 @@ def __init__(self, args):
         self._parse_extra_vars()  # handle multiple entries in --extra_vars arg
         self._prepend_venv_path()
 
+    def _parse_extra_vars_directives(self, value):
+        if isinstance(value, six.string_types):
+            if value.strip().startswith("!AST"):
+                a = ast.literal_eval(value.strip()[4:])
+                return self._parse_extra_vars_directives(a)
+            elif value.strip().startswith("!JSON"):
+                j = json.loads(value.strip()[5:])
+                return self._parse_extra_vars_directives(j)
+            elif value.strip().startswith("!INT"):
+                return int(value.strip()[4:])
+            else:
+                return value
+        elif isinstance(value, dict):
+            return {k: self._parse_extra_vars_directives(v) for k, v in six.iteritems(value)}
+        elif isinstance(value, list):
+            return [self._parse_extra_vars_directives(item) for item in value]
+        return value
+
     def _parse_extra_vars(self):
         """
         This method turns the string list ("--extra_vars=[...]") passed in from the args
@@ -50,10 +71,14 @@ def _parse_extra_vars(self):
                     if isinstance(n, six.string_types):
                         if n.strip().startswith("@"):
                             var_list.append(('file', n.strip()))
+                        elif (n.strip().startswith("!AST")
+                              or n.strip().startswith("!JSON")
+                              or '=' not in n):
+                            var_list.append(('json', self._parse_extra_vars_directives(n)))
                         else:
                             var_list.append(('kwarg', n.strip()))
                     elif isinstance(n, dict):
-                        var_list.append(('json', n))
+                        var_list.append(('json', self._parse_extra_vars_directives(n)))
 
                 last = ''
                 kv_param = ''

pack.yaml

@@ -6,6 +6,6 @@ keywords:
   - ansible
   - cfg management
   - configuration management
-version : 0.5.1
+version : 0.6.0
 author : StackStorm, Inc.
 email : [email protected]

tests/fixtures/extra_vars_complex.yaml

@@ -25,4 +25,70 @@
       key6:
         key7: 'value7'
     - 'key8=value8'
+-
+  name: ast_directive
+  test:
+    - "!AST{u'key1': u'12345', u'key2': u'value2'}"
+  expected:
+    -
+      key1: '12345'
+      key2: 'value2'
+-
+  name: json_directive
+  test:
+    - '!JSON{"key1": "12345", "key2": "value2"}'
+  expected:
+    -
+      key1: '12345'
+      key2: 'value2'
+-
+  name: sub_ast_directive
+  test:
+    -
+      astkey: "!AST[{u'key1': u'12345', u'key2': u'value2'}]"
+  expected:
+    -
+      astkey:
+        -
+          key1: '12345'
+          key2: 'value2'
+-
+  name: sub_json_directive
+  test:
+    -
+      jsonkey: '!JSON[{"key1": "12345", "key2": "value2"}]'
+  expected:
+    -
+      jsonkey:
+        -
+          key1: '12345'
+          key2: 'value2'
+-
+  name: int_directive
+  test:
+    -
+      key1: "!INT12345"
+  expected:
+    -
+      key1: 12345
+-
+  name: multi_directives_ast_int
+  test:
+    -
+      astkey: "!AST[{u'intkey': u'!INT12345'}]"
+  expected:
+    -
+      astkey:
+        -
+          intkey: 12345
+-
+  name: multi_directives_json_int
+  test:
+    -
+      jsonkey: '!JSON[{"intkey": "!INT12345"}]'
+  expected:
+    -
+      jsonkey:
+        -
+          intkey: 12345
 

tests/test_actions_lib_ansiblebaserunner.py

@@ -121,3 +121,24 @@ def extra_vars_complex_yaml_fixture(self, test_name):
 
     def test_parse_extra_vars_complex_yaml_arbitrarily_complex(self):
         self.extra_vars_complex_yaml_fixture('arbitrarily_complex')
+
+    def test_parse_extra_vars_complex_yaml_ast_directive(self):
+        self.extra_vars_complex_yaml_fixture('ast_directive')
+
+    def test_parse_extra_vars_complex_yaml_json_directive(self):
+        self.extra_vars_complex_yaml_fixture('json_directive')
+
+    def test_parse_extra_vars_complex_yaml_sub_ast_directive(self):
+        self.extra_vars_complex_yaml_fixture('sub_ast_directive')
+
+    def test_parse_extra_vars_complex_yaml_sub_json_directive(self):
+        self.extra_vars_complex_yaml_fixture('sub_json_directive')
+
+    def test_parse_extra_vars_complex_yaml_int_directive(self):
+        self.extra_vars_complex_yaml_fixture('int_directive')
+
+    def test_parse_extra_vars_complex_yaml_multi_directives_ast_int(self):
+        self.extra_vars_complex_yaml_fixture('multi_directives_ast_int')
+
+    def test_parse_extra_vars_complex_yaml_multi_directives_json_int(self):
+        self.extra_vars_complex_yaml_fixture('multi_directives_json_int')