Modified "vars:" not visible inside include_role.

[vbotka]

IMHO. Not included in https://github.com/ansible/ansible/projects/19

tested with ansible 2.9.6

SUMMARY

A modification of a variable declared in "vars" is not visible inside the included role.

    - include_role:
        name: test
        tasks_from: task.yml
      vars:
        my_var: A

ISSUE TYPE

• Bug Report

COMPONENT NAME

include_role

ANSIBLE VERSION

ansible 2.9.6
  config file = /export/home/vlado.config/.ansible/ansible-examples/examples/example-136/ansible.cfg
  configured module search path = ['/home/vlado/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python3/dist-packages/ansible
  executable location = /usr/bin/ansible
  python version = 3.8.2 (default, Apr 27 2020, 15:53:34) [GCC 9.3.0]

CONFIGURATION

DEFAULT_HOST_LIST(/export/home/vlado.config/.ansible/ansible-examples/examples/example-136/an$
DEFAULT_ROLES_PATH(/export/home/vlado.config/.ansible/ansible-examples/examples/example-136/a$

OS / ENVIRONMENT

Linux host9 5.4.0-31-generic #35-Ubuntu SMP Thu May 7 20:20:34 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

STEPS TO REPRODUCE

Fresh role with this task only

shell> cat roles/test/tasks/task.yml
- debug:
    var: my_var
- set_fact:
    my_var: B
- debug:
    var: my_var

- hosts: localhost
  connection: local
  tasks:
    - include_role:
        name: test
        tasks_from: task.yml
        apply:
          vars:
            my_var: A
    - debug:
        var: my_var

# Variable must be declared by "apply: vars".
#
#    "my_var": "A"
#    "my_var": "B"
#    "my_var": "B"

- hosts: localhost
  connection: local
  gather_facts: false
  tasks:
    - include_role:
        name: test
        tasks_from: task.yml
      vars:
        my_var: A
    - debug:
        var: my_var

# New copy visible outside the role only will be created if the variable
# is declared by "vars:".
#
#    "my_var": "A"
#    "my_var": "A"
#    "my_var": "B"

EXPECTED RESULTS

Fix the documentation

- name: Pass variables to role
  include_role:
    name: myrole
    apply:
      vars:
        rolevar1: value from task

ACTUAL RESULTS

Quoting from Examples
https://docs.ansible.com/ansible/latest/modules/include_role_module.html#examples

- name: Pass variables to role
  include_role:
    name: myrole
  vars:
    rolevar1: value from task

[vbotka]

Edit on GitHub fails: 404
https://docs.ansible.com/ansible/latest/modules/include_role_module.html

[Akasurde]

@vbotka "Edit on GitHub fail" is known and reported here - #69683 (comment)

[bcoca]

for full fix #69040

[vbotka]

Is (should be/will be) any difference between these options?

    - include_role:
        name: test
        tasks_from: task.yml
        apply:
          vars:
            my_var: A

and

    - include_role:
        name: test
        tasks_from: task.yml
      vars:
          my_var: A

[bcoca]

@vbotka mostly no, those should be almost the same, vars should be one of the few things that includes are both affected by and apply to included tasks, the only difference should be that the apply version defined variables would not be available to the include itself.

[bcoca]

other possible fix #75287

[nitzmahone]

Closing, since it looks like this was likely fixed awhile back. Feel free to reopen if this is still reproducible on currently-supported versions of Ansible Core.

[vbotka]

The problem, for your convenience also described here, is reproducible in 2.16.2

It seems, I can't reopen this issue. What do you mean by "Feel free to reopen" ?

[sivel]

Just to confirm something here, the behavior questioned in this issue is expected.

This is because vars: on an include_* are considered as include params. The variable precedence from https://docs.ansible.com/ansible-core/devel/playbook_guide/playbooks_variables.html#understanding-variable-precedence shows set_fact at 19 and include params at 21.

See the following for the code definition of include params:

ansible/lib/ansible/playbook/task.py

Lines 373 to 379 in 1b209d7

	def get_include_params(self):
	all_vars = dict()
	if self._parent:
	all_vars |= self._parent.get_include_params()
	if self.action in C._ACTION_ALL_INCLUDES:
	all_vars |= self.vars
	return all_vars

As a result, set_fact inside of a role that uses vars: at the include_role level has less precedence than the vars:. Outside the role, the set_fact has the higher precedence.

When using apply: for vars: they are no longer considered include params but instead are considered block vars which are 16 on the precedence list, so a set_fact will always win over apply vars from include_*.

Based on this, it appears this is just a misunderstanding across multiple pieces of documentation. Perhaps the only thing we may be missing is a description of what include params covers.

[vbotka]

vars: on an include_* are considered as include params.

Good to know.

... missing is a description of what include params covers.

... and this is known for two years.
ansible/ansible-documentation#95