recent change in Jinja breaks existing playbooks with jinja2_native=true

[Jean-Daniel]

SUMMARY

I have a simple playbook and since a released change in Jinja2 (2.11.2), my playbook now fails with error:

fatal: [localhost]: FAILED! => {"msg": "Invalid data passed to 'loop', it requires a list, got this instead: [('dsa', ''), ('dsa', '.pub'), ('rsa', ''), ('rsa', '.pub'), ('ecdsa', ''), ('ecdsa', '.pub'), ('ed25519', ''), ('ed25519', '.pub')]. Hint: If you passed a list/dict of just one element, try adding wantlist=True to your lookup invocation or use q/query instead of lookup."}

ISSUE TYPE

• Bug Report

COMPONENT NAME

template

ANSIBLE VERSION

ansible 2.9.7
  config file = /Users/jddupas/Desktop/ansible/ansible.cfg
  configured module search path = ['/Users/jddupas/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /Users/jddupas/Desktop/ansible/.venv/lib/python3.7/site-packages/ansible
  executable location = /Users/jddupas/Desktop/ansible/.venv/bin/ansible
  python version = 3.7.7 (default, Apr 18 2020, 15:06:20) [Clang 11.0.3 (clang-1103.0.32.59)]

CONFIGURATION

DEFAULT_JINJA2_NATIVE(/Users/jddupas/Desktop/ansible/ansible.cfg) = True

OS / ENVIRONMENT

Tested on macOS and Linux, with bare minimal inventory.

STEPS TO REPRODUCE

Run the following playbook (make sure you enable jinja2_native template).

- hosts: localhost
  tasks:
    - loop: "{{ [ 'dsa', 'rsa', 'ecdsa', 'ed25519' ] | product([ '', '.pub' ]) | list }}"
      debug:
        msg: "{{ item }}"

EXPECTED RESULTS

With Jinja 2.11.1, it work fine, with Jinja 2.11.2, it breaks with the error mentioned above.

ACTUAL RESULTS

TASK [debug] ***************************************************************************************************************************************************************************************************************
task path: loop.yaml:4
fatal: [localhost]: FAILED! => {
    "msg": "Invalid data passed to 'loop', it requires a list, got this instead: [('dsa', ''), ('dsa', '.pub'), ('rsa', ''), ('rsa', '.pub'), ('ecdsa', ''), ('ecdsa', '.pub'), ('ed25519', ''), ('ed25519', '.pub')]. Hint: If you passed a list/dict of just one element, try adding wantlist=True to your lookup invocation or use q/query instead of lookup."
}

[ansibot]

Files identified in the description:

• lib/ansible/modules/files/template.py

If these files are incorrect, please update the component name section of the description or use the !component bot command.

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[mkrizek]

So like I mentioned in pallets/jinja#1186 I cannot reproduce this with the devel branch. This does happen on 2.9. It has been fixed in #68938. The backport for 2.9 is opened in #69044.

So until the fix is backported, you can either downgrade Jinja2 or use Ansible's devel branch. I will leave this open until the fix is released.

Thanks!

[mkrizek]

I am going to go ahead and close this as the fix for this issue has been backported and will be included in the 2.9.8 release.