lookup templated value of a var (#32772)

* lookup templated value of a var
* better dupe loop detection
* corrected invalid test loops

lib/ansible/playbook/task.py

@@ -214,7 +214,7 @@ class Task(Base, Conditional, Taggable, Become):
             if k in ('action', 'local_action', 'args', 'delegate_to') or k == action or k == 'shell':
                 # we don't want to re-assign these values, which were determined by the ModuleArgsParser() above
                 continue
-            elif k.replace("with_", "") in lookup_loader:
+            elif k.startswith('with_') and k.replace("with_", "") in lookup_loader:
                 # transform into loop property
                 self._preprocess_with_loop(ds, new_ds, k, v)
             else:

lib/ansible/plugins/lookup/var.py

@@ -0,0 +1,100 @@
+# (c) 2017 Ansible Project
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+DOCUMENTATION = """
+    lookup: var
+    author: Ansible Core
+    version_added: "2.5"
+    short_description: Lookup templated value of variable
+    description:
+      - Retrieves the value of an Ansible variable.
+    options:
+      _term:
+        description: The variable name to look up.
+        required: True
+      default:
+        description:
+            - What to return when the variable is undefined.
+            - If no default is set, it will result in an error if the variable is undefined.
+"""
+
+EXAMPLES = """
+- name: Show value of 'variablename'
+  debug: msg="{{ lookup('var', 'variabl' + myvar)}}"
+  vars:
+    variablename: hello
+    myvar: ename
+
+- name: Show default empty since i dont have 'variablnotename'
+  debug: msg="{{ lookup('var', 'variabl' + myvar, default='')}}"
+  vars:
+    variablename: hello
+    myvar: notename
+
+- name: Produce an error since i dont have 'variablnotename'
+  debug: msg="{{ lookup('var', 'variabl' + myvar)}}"
+  ignore_errors: True
+  vars:
+    variablename: hello
+    myvar: notename
+
+- name:  find some 'prefixed vars' in loop
+  debug: msg="{{ lookup('var', 'ansible_play_' + item) }}"
+  loop:
+    - hosts
+    - batch
+    - hosts_all
+
+"""
+
+RETURN = """
+_value:
+  description:
+    - valueof the variable requested
+"""
+
+from ansible.errors import AnsibleError, AnsibleUndefinedVariable
+from ansible.module_utils.six import string_types
+from ansible.plugins.lookup import LookupBase
+
+
+class LookupModule(LookupBase):
+
+    def run(self, terms, variables=None, **kwargs):
+
+        ret = None
+        if variables is not None:
+            self._templar.set_available_variables(variables)
+        myvars = getattr(self._templar, '_available_variables', {})
+
+        self.set_options(direct=kwargs)
+        default = self.get_option('default')
+
+        # Assumes listify_plugin_terms is called previous to run so each term is already templated and terms is always a list
+        if isinstance(terms, list):
+            term = terms[0]
+        elif isinstance(terms, string_types):
+            term = terms
+        else:
+            raise AnsibleError('Invalid terms passed to "var" lookup, "%s" is not a string, its a %s' % (terms, type(terms)))
+
+        if not isinstance(term, string_types):
+            raise AnsibleError('Invalid setting identifier, "%s" is not a string, its a %s' % (term, type(term)))
+
+        try:
+            if term in myvars:
+                value = myvars[term]
+            elif 'hostvars' in myvars and term in myvars['hostvars']:
+                # maybe it is a host var?
+                value = myvars['hostvars'][term]
+            else:
+                raise AnsibleUndefinedVariable('No variable found with this name: %s' % term)
+            ret = self._templar.template(value, fail_on_undefined=True)
+        except AnsibleUndefinedVariable:
+            if default is None:
+                ret = default
+            else:
+                raise
+        return ret

test/integration/targets/docker_secret/tasks/Fedora.yml

@@ -2,7 +2,7 @@
   dnf:
     name: "{{ item }}"
     state: present
-  items:
+  loop:
     - dnf-plugins-core 
 
 - name: Add repository

test/integration/targets/docker_secret/tasks/RedHat.yml

@@ -5,7 +5,7 @@
   yum:
     name: "{{ item }}"
     state: present
-  items:
+  loop:
     - yum-utils
     - device-mapper-persistent-data
     - lvm2