For 2.0 How to test if variable set to null in when clause

Archives Ansible Project
1

pre 2.0

set_fact:
uberHost: “{{ ansible_ssh_host }}”
when: ansible_ssh_host is defined

set fact:
uberHost: “{{ inventory_hostname }}”
when: ansible_ssh_host is not defined

Post 2.0, changed to use ansible_host
uberHost is always getting set to null
ansible_host is defined and set to null even when it’s not present in the inventory file
I haven’t figured out how to test to see if ansible_host is null in a when clause.

2

It should be enough to just check:

when: ansible_ssh_host

However it may be good to come at it from a little different direction and use something like:

set_fact:
uberHost: “{{ ansible_ssh_host|default(inventory_hostname, True) }}”

The True in default() will tell jinja2 to use pythons truthyness checks, so an empty string evaluates as false as well.

3

you can even chain them and make it future proof
set_fact:
    uberHost: "{{
ansible_host|default(ansible_ssh_host|default(inventory_hostname,
True), True) }}"

4

when: ansible_host still caused the set_fact to execute when it was not present / null

However, the other suggestions worked great, thanks!