Jinja2 template error with for loops using fact variables

[Manjiri_28]

I am getting following error while executing playbook to create /etc/hosts like file using jinja2 template. For loop with fact variables are used in templates

An exception occurred during task execution. To see the full traceback, use -vvv. The error was: ansible.errors.AnsibleUndefinedVariable: 'dict object' has no attribute 'default_ipv4'. 'dict object' has no attribute 'default_ipv4'
fatal: [node1]: FAILED! => {"changed": false, "msg": "AnsibleUndefinedVariable: 'dict object' has no attribute 'default_ipv4'. 'dict object' has no attribute 'default_ipv4'"}

[bonnevil]

The fact ansible_facts['default_ipv4'] might only be set if you have a default route, so that the system can determine what it thinks your "default interface" is.  If you're on some disconnected network or don't have a default route for some reason, I don't think it gets a value even if you have IP addresses assigned to network interfaces that are up.  I'd have to check the docs to be certain.

[Trevor]

, 

Do me a favor, and add the following line (that I'm showing in BOLD)
to your playbook:

---
- name: Create hosts file on all managed hosts
  hosts: dev
  gathering_facts: true
  tasks:
     - name: Generate /etc/myhosts file using template
      ansible.builtin.template:
         src: hosts.j2
         dest: /etc/myhosts

Standing by ...

[ARoumiantsev]

Hi @Trevor  

Result same as was shown above.  gather_facts: true - is default setting

Alexandre

[student@workstation a]$ cat test.yml
---
- name: Create hosts file
hosts: dev
gather_facts: true
tasks:
- name: generate hosts
ansible.builtin.template:
src: hosts.j2
dest: /tmp/hosts
[student@workstation a]$ ansible-playbook test.yml

PLAY [Create hosts file] *******************************************************

TASK [Gathering Facts] *********************************************************
ok: [node1]

TASK [generate hosts] **********************************************************
fatal: [node1]: FAILED! => {"changed": false, "msg": "AnsibleUndefinedVariable: 'dict object' has no attribute 'default_ipv4'"}

PLAY RECAP *********************************************************************
node1 : ok=1 changed=0 unreachable=0 failed=1 skipped=0 rescued=0 ignored=0

[Trevor]

Thanks ARoumiantsev for your report on this.

May I now get you to replace, in the jinja2 code, "default_ipv4",
with "ansible_default_ipv4".

This is the only substitution - leave everything else as is!!!

Standing by....

[ARoumiantsev]

Hi @Trevor  

[student@workstation a]$ ansible-playbook test.yml

PLAY [Create hosts file] *******************************************************

TASK [Gathering Facts] *********************************************************
ok: [node1]

TASK [generate hosts] **********************************************************
fatal: [node1]: FAILED! => {"changed": false, "msg": "AnsibleUndefinedVariable: 'dict object' has no attribute 'ansible_default_ipv4'"}

PLAY RECAP *********************************************************************
node1 : ok=1 changed=0 unreachable=0 failed=1 skipped=0 rescued=0 ignored=0

[Trevor]

Thanks again ARoumiantsev!  I can now move on to investigating another 
possiblity.

[ARoumiantsev]

@Trevor To be clear: The situation is clear for me and  it is good explanation from @bonnevil above.  I only had tried to undestend the original issue from @Manjiri_28. For this propose I have reproduced possible version of his issue according info which he presented. It is intersting for me what is original issue - this one or something else?     Alexandre 

[Trevor]

Forgive me Alexadre, but I'm not real clear on your message.
Are you essentially saying that you have the resolution to the
issue?

[ARoumiantsev]

@Trevor   Solution is here ( see my post above

[student@workstation a]$ cat inventory
node2
[dev]
node1
[student@workstation a]$ ssh student@node2 ip route
172.25.249.0/24 dev eth1 proto kernel scope link src 172.25.249.10 metric 101
172.25.250.0/24 dev eth0 proto kernel scope link src 172.25.250.10 metric 100

and explanation see @bonnevil 

I am not sure that it is solution of original @Manjiri_28 's issue only

Alexandre

[Trevor]

Alexamdre. do me another favor, and execute the following
command:         #  ansible  all  -m  setup

I just want to see what (if any) facts are being retrieved.

Standing by ...