Fix extract filter when key does not exist in container (#64959)

Fixes #64957

changelogs/fragments/64959-extract-filter-when-key-does-not-exist.yml

@@ -0,0 +1,3 @@
+bugfixes:
+  - core filters - fix ``extract()`` filter when key does not exist in container
+    (https://github.com/ansible/ansible/issues/64957)

lib/ansible/plugins/filter/core.py

@@ -410,19 +410,18 @@ def comment(text, style='plain', **kw):
         str_end)
 
 
-def extract(item, container, morekeys=None):
-    from jinja2.runtime import Undefined
+@environmentfilter
+def extract(environment, item, container, morekeys=None):
+    if morekeys is None:
+        keys = [item]
+    elif isinstance(morekeys, list):
+        keys = [item] + morekeys
+    else:
+        keys = [item, morekeys]
 
-    value = container[item]
-
-    if value is not Undefined and morekeys is not None:
-        if not isinstance(morekeys, list):
-            morekeys = [morekeys]
-
-        try:
-            value = reduce(lambda d, k: d[k], morekeys, value)
-        except KeyError:
-            value = Undefined()
+    value = container
+    for key in keys:
+        value = environment.getitem(value, key)
 
     return value
 

lib/ansible/vars/hostvars.py

@@ -19,10 +19,8 @@
 from __future__ import (absolute_import, division, print_function)
 __metaclass__ = type
 
-from jinja2.runtime import Undefined
-
 from ansible.module_utils.common._collections_compat import Mapping
-from ansible.template import Templar
+from ansible.template import Templar, AnsibleUndefined
 
 STATIC_VARS = [
     'ansible_version',
@@ -75,13 +73,13 @@ class HostVars(Mapping):
         '''
         host = self._find_host(host_name)
         if host is None:
-            return Undefined(name="hostvars['%s']" % host_name)
+            return AnsibleUndefined(name="hostvars['%s']" % host_name)
 
         return self._variable_manager.get_vars(host=host, include_hostvars=False)
 
     def __getitem__(self, host_name):
         data = self.raw_get(host_name)
-        if isinstance(data, Undefined):
+        if isinstance(data, AnsibleUndefined):
             return data
         return HostVarsVars(data, loader=self._loader)
 

test/integration/targets/filters/tasks/main.yml

@@ -116,6 +116,29 @@
   # map was added to jinja2 in version 2.7
   when: "{{ ( lookup('pipe', '{{ ansible_python[\"executable\"] }} -c \"import jinja2; print(jinja2.__version__)\"')  is version('2.7', '>=') ) }}"
 
+- name: Test extract filter with defaults
+  vars:
+    container:
+      key:
+        subkey: value
+  assert:
+    that:
+      - "'key' | extract(badcontainer) | default('a') == 'a'"
+      - "'key' | extract(badcontainer, 'subkey') | default('a') == 'a'"
+      - "('key' | extract(badcontainer)).subkey | default('a') == 'a'"
+      - "'badkey' | extract(container) | default('a') == 'a'"
+      - "'badkey' | extract(container, 'subkey') | default('a') == 'a'"
+      - "('badkey' | extract(container)).subsubkey | default('a') == 'a'"
+      - "'key' | extract(container, 'badsubkey') | default('a') == 'a'"
+      - "'key' | extract(container, ['badsubkey', 'subsubkey']) | default('a') == 'a'"
+      - "('key' | extract(container, 'badsubkey')).subsubkey | default('a') == 'a'"
+      - "'badkey' | extract(hostvars) | default('a') == 'a'"
+      - "'badkey' | extract(hostvars, 'subkey') | default('a') == 'a'"
+      - "('badkey' | extract(hostvars)).subsubkey | default('a') == 'a'"
+      - "'localhost' | extract(hostvars, 'badsubkey') | default('a') == 'a'"
+      - "'localhost' | extract(hostvars, ['badsubkey', 'subsubkey']) | default('a') == 'a'"
+      - "('localhost' | extract(hostvars, 'badsubkey')).subsubkey | default('a') == 'a'"
+
 - name: Test json_query filter
   assert:
     that:
@@ -239,10 +262,10 @@
   assert:
     that:
             - "'00' | random_mac is match('^00:[a-f0-9][a-f0-9]:[a-f0-9][a-f0-9]:[a-f0-9][a-f0-9]:[a-f0-9][a-f0-9]:[a-f0-9][a-f0-9]$')"
-            - "'00:00' | random_mac is match('^00:00:[a-f0-9][a-f0-9]:[a-f0-9][a-f0-9]:[a-f0-9][a-f0-9]:[a-f0-9][a-f0-9]$')"  
+            - "'00:00' | random_mac is match('^00:00:[a-f0-9][a-f0-9]:[a-f0-9][a-f0-9]:[a-f0-9][a-f0-9]:[a-f0-9][a-f0-9]$')"
             - "'00:00:00' | random_mac is match('^00:00:00:[a-f0-9][a-f0-9]:[a-f0-9][a-f0-9]:[a-f0-9][a-f0-9]$')"
             - "'00:00:00:00' | random_mac is match('^00:00:00:[a-f0-9][a-f0-9]:[a-f0-9][a-f0-9]:[a-f0-9][a-f0-9]$')"
-            - "'00:00:00:00:00' | random_mac is match('^00:00:00:00:00:[a-f0-9][a-f0-9]$')"  
+            - "'00:00:00:00:00' | random_mac is match('^00:00:00:00:00:[a-f0-9][a-f0-9]$')"
             - "'00:00:00' | random_mac != '00:00:00' | random_mac"
 
 - name: Verify random_mac filter with seed