Deprecate using a list of dicts for vars. See #78920 (#78927)

10 files changed, 45 insertions, 21 deletions

diff --git a/changelogs/fragments/deprecate-vars-list-of-dicts.yml b/changelogs/fragments/deprecate-vars-list-of-dicts.yml
new file mode 100644
index 0000000000..352bf37745
--- /dev/null
+++ b/changelogs/fragments/deprecate-vars-list-of-dicts.yml
@@ -0,0 +1,2 @@
+deprecated_features:
+- vars - Specifying a list of dictionaries for ``vars:`` is deprecated in favor of specifying a dictionary.
diff --git a/docs/docsite/rst/porting_guides/porting_guide_core_2.15.rst b/docs/docsite/rst/porting_guides/porting_guide_core_2.15.rst
index 12939c7b83..782288c1d1 100644
--- a/docs/docsite/rst/porting_guides/porting_guide_core_2.15.rst
+++ b/docs/docsite/rst/porting_guides/porting_guide_core_2.15.rst
@@ -31,8 +31,23 @@ No notable changes
 Deprecated
 ==========
 
-No notable changes
+* Providing a list of dictionaries to ``vars:`` is deprecated in favor of supplying a dictionary.
+
+  Instead of:
+
+  .. code-block:: yaml
+
+     vars:
+       - var1: foo
+       - var2: bar
+
+  Use:
+
+  .. code-block:: yaml
 
+     vars:
+       var1: foo
+       var2: bar
 
 Modules
 =======
diff --git a/lib/ansible/playbook/base.py b/lib/ansible/playbook/base.py
index ae7957b0bc..68b98ca184 100644
--- a/lib/ansible/playbook/base.py
+++ b/lib/ansible/playbook/base.py
@@ -570,6 +570,13 @@ class FieldAttributeBase:
                 _validate_variable_keys(ds)
                 return combine_vars(self.vars, ds)
             elif isinstance(ds, list):
+                display.deprecated(
+                    (
+                        'Specifying a list of dictionaries for vars is deprecated in favor of '
+                        'specifying a dictionary.'
+                    ),
+                    version='2.18'
+                )
                 all_vars = self.vars
                 for item in ds:
                     if not isinstance(item, dict):
@@ -582,7 +589,7 @@ class FieldAttributeBase:
             else:
                 raise ValueError
         except ValueError as e:
-            raise AnsibleParserError("Vars in a %s must be specified as a dictionary, or a list of dictionaries" % self.__class__.__name__,
+            raise AnsibleParserError("Vars in a %s must be specified as a dictionary" % self.__class__.__name__,
                                      obj=ds, orig_exc=e)
         except TypeError as e:
             raise AnsibleParserError("Invalid variable name in vars specified for %s: %s" % (self.__class__.__name__, e), obj=ds, orig_exc=e)
diff --git a/test/integration/targets/ansible-vault/test_vault.yml b/test/integration/targets/ansible-vault/test_vault.yml
index 7f8ed11570..c21d49a6e0 100644
--- a/test/integration/targets/ansible-vault/test_vault.yml
+++ b/test/integration/targets/ansible-vault/test_vault.yml
@@ -1,6 +1,6 @@
 - hosts: testhost
   gather_facts: False
   vars:
-    - output_dir: .
+    output_dir: .
   roles:
     - { role: test_vault, tags: test_vault}
diff --git a/test/integration/targets/ansible-vault/test_vaulted_template.yml b/test/integration/targets/ansible-vault/test_vaulted_template.yml
index b495211de8..6a16ec864d 100644
--- a/test/integration/targets/ansible-vault/test_vaulted_template.yml
+++ b/test/integration/targets/ansible-vault/test_vaulted_template.yml
@@ -1,6 +1,6 @@
 - hosts: testhost
   gather_facts: False
   vars:
-    - output_dir: .
+    output_dir: .
   roles:
     - { role: test_vaulted_template, tags: test_vaulted_template}
diff --git a/test/integration/targets/blocks/unsafe_failed_task.yml b/test/integration/targets/blocks/unsafe_failed_task.yml
index adfa492ad9..e74327b9f8 100644
--- a/test/integration/targets/blocks/unsafe_failed_task.yml
+++ b/test/integration/targets/blocks/unsafe_failed_task.yml
@@ -1,7 +1,7 @@
 - hosts: localhost
   gather_facts: false
   vars:
-    - data: {}
+    data: {}
   tasks:
     - block:
         - name: template error
diff --git a/test/integration/targets/check_mode/check_mode.yml b/test/integration/targets/check_mode/check_mode.yml
index a5777506ff..ebf1c5b562 100644
--- a/test/integration/targets/check_mode/check_mode.yml
+++ b/test/integration/targets/check_mode/check_mode.yml
@@ -1,7 +1,7 @@
 - name: Test that check works with check_mode specified in roles
   hosts: testhost
   vars:
-  - output_dir: .
+    output_dir: .
   roles:
   - { role: test_always_run, tags: test_always_run }
   - { role: test_check_mode, tags: test_check_mode }
diff --git a/test/integration/targets/delegate_to/test_delegate_to.yml b/test/integration/targets/delegate_to/test_delegate_to.yml
index dcfa9d0351..34cfd20942 100644
--- a/test/integration/targets/delegate_to/test_delegate_to.yml
+++ b/test/integration/targets/delegate_to/test_delegate_to.yml
@@ -1,9 +1,9 @@
 - hosts: testhost3
   vars:
-    - template_role: ./roles/test_template
-    - output_dir: "{{ playbook_dir }}"
-    - templated_var: foo
-    - templated_dict: { 'hello': 'world' }
+    template_role: ./roles/test_template
+    output_dir: "{{ playbook_dir }}"
+    templated_var: foo
+    templated_dict: { 'hello': 'world' }
   tasks:
     - name: Test no delegate_to
       setup:
diff --git a/test/integration/targets/environment/test_environment.yml b/test/integration/targets/environment/test_environment.yml
index 43f9c74eb6..f295cf3cab 100644
--- a/test/integration/targets/environment/test_environment.yml
+++ b/test/integration/targets/environment/test_environment.yml
@@ -7,8 +7,8 @@
 
 - hosts: testhost
   vars:
-    - test1:
-        key1: val1
+    test1:
+      key1: val1
   environment:
     PATH: '{{ansible_env.PATH + ":/lola"}}'
     lola: 'ido'
@@ -41,9 +41,9 @@
 
 - hosts: testhost
   vars:
-    - test1:
-        key1: val1
-    - test2:
+    test1:
+      key1: val1
+    test2:
         key1: not1
         other1: val2
   environment: "{{test1}}"
diff --git a/test/integration/targets/var_precedence/test_var_precedence.yml b/test/integration/targets/var_precedence/test_var_precedence.yml
index 58584bfb3e..b432b2bd6f 100644
--- a/test/integration/targets/var_precedence/test_var_precedence.yml
+++ b/test/integration/targets/var_precedence/test_var_precedence.yml
@@ -1,12 +1,12 @@
 ---
 - hosts: testhost
   vars:
-    - ansible_hostname: "BAD!"
-    - vars_var: "vars_var"
-    - param_var: "BAD!"
-    - vars_files_var: "BAD!"
-    - extra_var_override_once_removed: "{{ extra_var_override }}"
-    - from_inventory_once_removed: "{{ inven_var | default('BAD!') }}"
+    ansible_hostname: "BAD!"
+    vars_var: "vars_var"
+    param_var: "BAD!"
+    vars_files_var: "BAD!"
+    extra_var_override_once_removed: "{{ extra_var_override }}"
+    from_inventory_once_removed: "{{ inven_var | default('BAD!') }}"
   vars_files:
     - vars/test_var_precedence.yml
   roles: