list concatenation using "set_fact" and "with_items" not working (regression)

[unicode-it]

Summary

Loops with set_fact do not behave like they used to. Unless this change is intended or documented somewhere, it is a regression. Maybe it is related to breaking changes with jinja3.

Issue Type

Bug Report

Component Name

core, jinja

Ansible Version

$ ansible --version
ansible [core 2.14.2]
  config file = /home/xxx/xxx/ansible.cfg
  configured module search path = ['/home/user/xxx']
  ansible python module location = /home/xxx/xxx
  ansible collection location = /home/user/xxx/collections
  executable location = /home/xxx/bin/ansible
  python version = 3.9.2 (default, Feb 28 2021, 17:03:44) [GCC 10.2.1 20210110] (/home/xxx/bin/python)
  jinja version = 3.0.3
  libyaml = True

Configuration

# if using a version older than ansible-core 2.12 you should omit the '-t all'
$ ansible-config dump --only-changed -t all
(unrelated)

OS / Environment

Debian bullseye

Steps to Reproduce

Vars:

shares:
  - name: something
    type: nfs4
    from:
      nfs_server:
        path: /export/recordings/unpublished
        options: "rw,sync,no_root_squash,no_subtree_check"
    to:
      nfs_client1:
        path: /some/folder/
        opts: rw,auto,nofail
      nfs_client2:
        path: /some/folder/
        opts: rw,auto,nofail

Task:

- name: create vars for nfs role
  set_fact:
    nfs_exports: "{{ nfs_exports | default([]) }} + [ '/share/{{item.from[ansible_host].path.split('/')[-1]}}      {% for client in item.to | default([]) %}{{ips_intern[client]}} {% endfor %}{% for host in item.from[ansible_host].hosts | default([]) %}{{host}}({{item.from[ansible_host].options}}) {% endfor %}']"
  with_items: "{{shares}}"
  when:
    - "'nfs_servers' in group_names"
    - "ansible_host in item.from"
    - "item.from[ansible_host].hosts is defined"

Expected Results

"nfs_exports": ['/share fd75:5a92:ipv6 fd75:5a92:ipv6 ', '/share fd75:5a92:ipv6 fd75:5a92:ipv6 ']

Actual Results

"nfs_exports": "[] + ['/share      fd75:5a92:ipv6 fd75:5a92:ipv6 '] + ['/share      fd75:5a92:ipv6 fd75:5a92:ipv6 ']"

Since update to this ansible Version a string is generated. Concat of lists does not work any more. With {{ nfs_exports | default([]) | list }} it works as expected, but the list filter breaks the wrong interpretated string into single characters: ["[", "]"]

Code of Conduct

• I agree to follow the Ansible Code of Conduct

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Files identified in the description:
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[flowerysong]

This is not a bug. You are doing concatenation outside of a Jinja expression, which used to work due to a bug but was never intended behavior. As noted in the porting guide {{ [1] }} + [2] should instead be written as a single Jinja expression, {{ [1] + [2] }}.

[unicode-it]

Thanks for the clarification.
But this doesn't solve the use case above. Because that way Jinja expression (for loop) cannot be used any more. It cannot be put within {{ }}.
Can you help how this logic can be ported?

[flowerysong]

The lazy way is to just put it in a separate variable.

- name: create vars for nfs role
  set_fact:
    nfs_exports: "{{ nfs_exports | default([]) + [new_export] }}"
  loop: "{{ shares }}"
  vars:
    new_export: /share/{{item.from[ansible_host].path.split('/')[-1]}}      {% for client in item.to | default([]) %}{{ips_intern[client]}} {% endfor %}{% for host in item.from[ansible_host].hosts | default([]) %}{{host}}({{item.from[ansible_host].options}}) {% endfor %}
  when:
    - "'nfs_servers' in group_names"
    - "ansible_host in item.from"
    - "item.from[ansible_host].hosts is defined"

[unicode-it]

True that is an easy solution. Thx alot.

I am closing this issue.