conditional in template?

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1

All,

I’m attempting to use a conditional in a template, without success. Specifically I’m trying to add an iptable rule that allows traffic sourced from eth1 on all hosts:

Below is the relevant portion of the template:

{% if ‘eth1’ in ansible_interfaces %}
{% if hostvars[host][‘ansible_eth1’][‘ipv4’][‘address’] is defined %}
-A INPUT -s {{ hostvars[host][‘ansible_eth1’][‘ipv4’][‘address’] }} -j ACCEPT
{% endif %}
{% endif %}
{% endfor %}

Unfortunately the playbook still errors out:

fatal: [test2] => {‘msg’: “AnsibleUndefinedVariable: One or more undefined variables: ‘dict object’ has no attribute ‘ipv4’”, ‘failed’: True}

This server does indeed have an eth1 interface but said interface does not have an IP address in this particular case.

This “if x is defined” syntax seems to work fine in a “when:” conditional in the playbook, just not in the template itself.

Any thoughts on what I may be doing wrong and how to rectify this error / problem?

Many thanks!

2

Hi. The “is defined” portion is failing because of the ‘ipv4’ subkey failure. You will have to do something like this:

{% if ‘ipv4’ in hostvars[host][‘ansible_eth1’] and hostvars[host][‘ansible_eth1’][‘ipv4’][‘address’] is defined %}

If that’s still not working, and ansible_eth1 does have the ‘ipv4’ entry, then this is most likely a fact-gathering issue, where the targeted host hasn’t yet gathered facts. If so, you can make sure facts are gathered about all systems by adding a simple initial play to your playbook:

  • hosts: all
    gather_facts: yes

Hope that helps!