Conditional evaluation of lists

[Anand Buddhdev]

I want to install some packages on a server. Additionally, if a certain condition is true, I want to add an extra package to the list of packages to be installed. What I would love is have this:

- name: install packages

  yum: name={{ item }}

  with_items:

    - package1

    - package2

{% if condition %}

    - package3

{% endif %}

Now, I know that ansible doesn't parse playbooks with the full Jinja engine (though that would be so cool). I could of course achieve this with 2 tasks:

- name: install packages

  yum: name={{ item }}

  with_items:

    - package1

    - package2

- name: install packages

  yum: name=package3

  when: condition

But my question is: how can I achieve this with just one task?

[Brian Coca]

try:

with_items:
- p1
- p2
- "{{ condition|ternary(p3,'') }}"

or

with_items: "{{ ['p1','p2'] |union(condition|ternary(['p3'],[ ])) }}"
--
Brian Coca

[Anand Buddhdev]

On Friday, 27 March 2015 23:18:15 UTC+1, Brian Coca wrote:

Hi Brian,

with_items:
  - p1
  - p2
  - "{{ condition|ternary(p3,'') }}"

This yields an empty list item, and the yum module doesn't like it.

 

or

with_items: "{{ ['p1','p2'] |union(condition|ternary(['p3'],[ ])) }}"

Using ansible 1.9.0.1, this fails with:

fatal: [10.0.0.63] => an unexpected type error occurred. Error was can only concatenate list (not "bool") to list