Added "debug: var=variableName" capability.

CHANGELOG.md

@@ -16,6 +16,7 @@ Highlighted new features:
 * The roles search path is now configurable in ansible.cfg.  'roles_path' in the config setting.
 * Includes with parameters can now be done like roles for consistency:  - { include: song.yml, year:1984, song:'jump' }
 * The name of each role is now shown before each task if roles are being used
+* Adds a "var=" option to the debug module for debugging variable data.  "debug: var=hostvars['hostname']" and "debug: var=foo" are all valid syntax.
 
 New modules and plugins:
 

lib/ansible/callbacks.py

@@ -484,7 +484,7 @@ class PlaybookRunnerCallbacks(DefaultRunnerCallbacks):
 
         host_result2 = host_result.copy()
         host_result2.pop('invocation', None)
-        verbose_always = host_result2.pop('verbose_always', None)
+        verbose_always = host_result2.pop('verbose_always', False)
         changed = host_result.get('changed', False)
         ok_or_changed = 'ok'
         if changed:
@@ -493,7 +493,7 @@ class PlaybookRunnerCallbacks(DefaultRunnerCallbacks):
         # show verbose output for non-setup module results if --verbose is used
         msg = ''
         if (not self.verbose or host_result2.get("verbose_override",None) is not
-                None) and verbose_always is None:
+                None) and not verbose_always:
             if item:
                 msg = "%s: [%s] => (item=%s)" % (ok_or_changed, host, item)
             else:
@@ -502,10 +502,10 @@ class PlaybookRunnerCallbacks(DefaultRunnerCallbacks):
         else:
             # verbose ...
             if item:
-                msg = "%s: [%s] => (item=%s) => %s" % (ok_or_changed, host, item, utils.jsonify(host_result2))
+                msg = "%s: [%s] => (item=%s) => %s" % (ok_or_changed, host, item, utils.jsonify(host_result2, format=verbose_always))
             else:
                 if 'ansible_job_id' not in host_result or 'finished' in host_result2:
-                    msg = "%s: [%s] => %s" % (ok_or_changed, host, utils.jsonify(host_result2))
+                    msg = "%s: [%s] => %s" % (ok_or_changed, host, utils.jsonify(host_result2, format=verbose_always))
 
         if msg != '':
             if not changed:

lib/ansible/runner/action_plugins/debug.py

@@ -38,13 +38,21 @@ class ActionModule(object):
 
         kv = utils.parse_kv(module_args)
         args.update(kv)
-        if not 'msg' in args:
+
+        if not 'msg' in args and not 'var' in args:
             args['msg'] = 'Hello world!'
 
-        if 'fail' in args and utils.boolean(args['fail']):
-            result = dict(failed=True, msg=args['msg'])
-        else:
-            result = dict(msg=args['msg'])
+        result = {}
+        if 'msg' in args:
+            if 'fail' in args and utils.boolean(args['fail']):
+                result = dict(failed=True, msg=args['msg'])
+            else:
+                result = dict(msg=args['msg'])
+        elif 'var' in args:
+            (intermediate, exception) = utils.safe_eval(args['var'], inject, include_exceptions=True, template_call=True)
+            if exception is not None:
+                intermediate = "failed to evaluate: %s" % str(exception)
+            result[args['var']] = intermediate
 
         # force flag to make debug output module always verbose
         result['verbose_always'] = True

lib/ansible/utils/__init__.py

@@ -896,16 +896,20 @@ def is_list_of_strings(items):
             return False
     return True
 
-def safe_eval(str):
+def safe_eval(str, locals=None, include_exceptions=False, template_call=False):
     '''
     this is intended for allowing things like:
-    with_items: {{ a_list_variable }}
+    with_items: a_list_variable
     where Jinja2 would return a string
     but we do not want to allow it to call functions (outside of Jinja2, where
     the env is constrained)
     '''
     # FIXME: is there a more native way to do this?
 
+    if template_call:
+        # for the debug module in Ansible, allow debug of the form foo.bar.baz versus Python dictionary form
+        str = template.template(None, "{{ %s }}" % str, locals)
+
     def is_set(var):
         return not var.startswith("$") and not '{{' in var
 
@@ -922,8 +926,18 @@ def safe_eval(str):
     if re.search(r'import \w+', str):
         return str
     try:
-        return eval(str)
+        result = None
+        if not locals:
+            result = eval(str)
+        else:
+            result = eval(str, None, locals)
+        if include_exceptions:
+            return (result, None)
+        else:
+            return result
     except Exception, e:
+        if include_exceptions:
+            return (str, e)
         return str
 
 

library/utilities/debug

@@ -35,7 +35,10 @@ options:
         message.
     required: false
     default: "Hello world!"
-author: Dag Wieers
+  var:
+    description:
+      - A variable name to debug.  Mutually exclusive with the 'msg' option.
+author: Dag Wieers, Michael DeHaan
 '''
 
 EXAMPLES = '''
@@ -44,4 +47,9 @@ EXAMPLES = '''
 
 - debug: msg="System {{ inventory_hostname }} has gateway {{ ansible_default_ipv4.gateway }}"
   when: ansible_default_ipv4.gateway is defined
+
+- shell: /usr/bin/uptime
+  register: result
+- debug: var=result
+
 '''