Inconsistent results while formatting a list with Ansible-CodePudding

I'm using Ansible to build inventories dynamically according to several parameters.

I get raw info from our CMDB's API, then use set_fact to format a list of FQDNs.

Those FQDNs always follow the same formula, so it looks easy, but Ansible only seems to apply the templating to the first item.

The code:

  - name: populate list of all hosts
    set_fact:
      all_hosts: '{{ all_hosts   [ "{{item.value.fields.friendlyname | lower}}" "." "{{item.value.fields.friendlyname[:3]|lower}}" ".sncoia.lan" ] }}'
    loop: "{{ hostname.json.objects | dict2items }}"
    when: 
    - item.value.fields.friendlyname | length == 12

  - debug: var=all_hosts

The result (abridged for brevity):

TASK [debug] **********************************************************************************************************************************************************************************
ok: [localhost] => {
    "all_hosts": [
        "devlappaps03.dev.sncoia.lan",
        "{{item.value.fields.friendlyname | lower}}.{{item.value.fields.friendlyname[:3]|lower}}.sncoia.lan",
        "{{item.value.fields.friendlyname | lower}}.{{item.value.fields.friendlyname[:3]|lower}}.sncoia.lan",

CodePudding user response：

Given the data for testing

    hostname:
      json:
        objects:
          foo:
            fields:
              friendlyname: devlappaps03
          bar:
            fields:
              friendlyname: devlappaps02
          baz:
            fields:
              friendlyname: devlappaps01

Properly concatenate the FQDN. For example

    - set_fact:
        all_hosts: "{{ all_hosts|d([])   [_fqdn] }}"
      loop: "{{ hostname.json.objects|dict2items }}"
      when: item.value.fields.friendlyname|length == 12
      vars:
        _fqdn_list:
          - "{{ item.value.fields.friendlyname|lower }}"
          - "{{ item.value.fields.friendlyname[:3]|lower }}"
          - "sncoia.lan"
        _fqdn: "{{ _fqdn_list|join('.') }}"

gives

all_hosts:
  - devlappaps03.dev.sncoia.lan
  - devlappaps02.dev.sncoia.lan
  - devlappaps01.dev.sncoia.lan