How to run an Ansible task if *any* host has a fact - ansible

Question

I'm wrapping my head around something that I'm probably overcomplicating.
I need to check if any of my hosts has ansible_virtualization_type == "openvz"
If this is the case, ALL hosts should execute a specific task.
I'm now trying to set a fact (virt_list) containing a list of hosts with their virtualization_type on localhost:
- name: Set fuse on virtualization OpenVZ
set_fact:
virt_list:
host: "{{item}}"
type: "openvz"
when: hostvars[item].ansible_virtualization_type == "openvz"
with_items: "{{ groups['all'] }}"
delegate_to: localhost
delegate_facts: true
but this doesn't work (both hosts in this play are on openvz):
TASK [roles/testvirt : debug vars ansible_virtualization_type ] ****************************
ok: [host1] => {
"ansible_virtualization_type": "openvz"
}
ok: [host2] => {
"ansible_virtualization_type": "openvz"
}
TASK [roles/testvirt : debug vars virt_list ] **********************************************
ok: [host1] => {
"msg": [
{
"host": "host1",
"type": "openvz"
}
]
}
ok: [host2] => {
"msg": [
{
"host": "host2",
"type": "openvz"
}
]
}
There should be a simpler way, maybe using jinjia2 to combine the lists directly.
Anyone has advices?

Answer 1

Q: "If any of my hosts has ansible_virtualization_type == "openvz" ALL hosts should execute a specific task."
A: For example, given the inventory for testing
shell> cat hosts
host1 ansible_virtualization_type=xen
host2 ansible_virtualization_type=xen
host3 ansible_virtualization_type=openvz
extract the variables
- debug:
msg: "{{ ansible_play_hosts|
map('extract', hostvars, 'ansible_virtualization_type')|
list }}"
run_once: true
gives
msg:
- xen
- xen
- openvz
Test if the type is present
- debug:
msg: OK. ALL hosts should execute a specific task.
when: "'openvz' in vtypes"
vars:
vtypes: "{{ ansible_play_hosts|
map('extract', hostvars, 'ansible_virtualization_type')|
list }}"
run_once: true
gives
msg: OK. ALL hosts should execute a specific task.
If this is working as expected proceed with all hosts
- set_fact:
all_hosts_execute_specific_task: true
when: "'openvz' in vtypes"
vars:
vtypes: "{{ ansible_play_hosts|
map('extract', hostvars, 'ansible_virtualization_type')|
list }}"
run_once: true
- debug:
msg: Execute a specific task.
when: all_hosts_execute_specific_task|default(false)
gives
TASK [set_fact] ************************************************************
ok: [host1]
TASK [debug] ***************************************************************
ok: [host1] =>
msg: Execute a specific task.
ok: [host3] =>
msg: Execute a specific task.
ok: [host2] =>
msg: Execute a specific task.
The task will be skipped if the type is missing.