Extracting nested object in Jinja2 - ansible

Question

I need to extract IPv4 addresses for specific interface from hostvars in Ansible Jinja2 template without loops using.
Trying to extract 'ansible_eth1' object from hostvars is successful and Ansible provides me all info about `eth1' interface:
- debug:
msg: "{{ groups['my_hosts'] | map('extract', hostvars, 'ansible_eth1') | join(', ') }}"
TASK [my_task : debug] *****************************************************************************************************************************************************************************************************
ok: [server1] => {
"msg": [
{
"active": true,
"device": "eth1",
...
"ipv4": {
"address": "192.168.56.15",
"broadcast": "192.168.56.255",
"netmask": "255.255.255.0",
"network": "192.168.56.0"
},
...
But if I try to extract nested object - 'ipv4.address' - it returns empty list:
- debug:
msg: "{{ groups['my_hosts'] | map('extract', hostvars, 'ansible_eth1.ipv4.address') | join(', ') }}"
TASK [my_task : debug] *****************************************************************************************************************************************************************************************************
ok: [server1] => {
"msg": ", "
}
ok: [server2] => {
"msg": ", "
}
Is it possible?

Answer 1

The behavior you are after is specified by the final line in the extract section, where it says "The third argument to the filter can also be a list, for a recursive lookup inside the container"
Thus, in your case:
msg: "{{ groups['my_hosts']
| map('extract', hostvars, ['ansible_eth1', 'ipv4', 'address'])
| join(', ') }}"