Rename var lookup to vars and add tests

lib/ansible/plugins/lookup/vars.py

@@ -0,0 +1,96 @@
+# (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: vars
+    author: Ansible Core
+    version_added: "2.5"
+    short_description: Lookup templated value of variables
+    description:
+      - Retrieves the value of an Ansible variable.
+    options:
+      _term:
+        description: The variable names to look up.
+        required: True
+      default:
+        description:
+            - What to return if a variable is undefined.
+            - If no default is set, it will result in an error if any of the variables is undefined.
+"""
+
+EXAMPLES = """
+- name: Show value of 'variablename'
+  debug: msg="{{ lookup('vars', 'variabl' + myvar)}}"
+  vars:
+    variablename: hello
+    myvar: ename
+
+- name: Show default empty since i dont have 'variablnotename'
+  debug: msg="{{ lookup('vars', 'variabl' + myvar, default='')}}"
+  vars:
+    variablename: hello
+    myvar: notename
+
+- name: Produce an error since i dont have 'variablnotename'
+  debug: msg="{{ lookup('vars', 'variabl' + myvar)}}"
+  ignore_errors: True
+  vars:
+    variablename: hello
+    myvar: notename
+
+- name: find several related variables:
+  debug: msg="{{ lookup('vars', 'ansible_play_hosts', 'ansible_play_batch', 'ansible_play_hosts_all') }}"
+
+- name: alternate way to find some 'prefixed vars' in loop
+  debug: msg="{{ lookup('vars', 'ansible_play_' + item) }}"
+  loop:
+    - hosts
+    - batch
+    - hosts_all
+"""
+
+RETURN = """
+_value:
+  description:
+    - valueof the variables 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):
+        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')
+
+        ret = []
+        for term in 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.append(self._templar.template(value, fail_on_undefined=True))
+
+            except AnsibleUndefinedVariable:
+                if default is not None:
+                    ret.append(default)
+                else:
+                    raise
+
+        return ret