Ansible: Multiple and/or conditionals in when clause

Question

I am having issues when trying to use multiple and/or conditionals in a when statement to decide whether a task needs to be ran or not. Basically I am making a playbook to do automated system patching with options for security patches, kernel only patches and to specify packages in a var file.

I run the playbook with the following commands and define the variables through extended variables option (-e)

ansible-playbook site.yml -i inventory --ask-vault -u (username) -e "security=true restart=true" -k -K

By default the playbook will update every package on the system except kernel but I would like to skip that action if I specify any of a few variables. The code I have is the following:

- name: Update all packages
  yum:
     name: "*"
     state: latest
     exclude: "kernel*"
  when: security is not defined or kernel is not defined  or specified_packages 
 is not defined and ansible_os_family == "RedHat" 

Ive tried all of the following combinations:

when: (ansible_os_family == "RedHat") and (security is defined or kernel is defined or specified_packages is defined)

when: (ansible_os_family == "RedHat") and (security == true or kernel == true or specified_packages == true ) <- this case throws a not defined error because i don't define all variables every time i run the playbook

when: ansible_os_family == "RedHat" when: security is defined or kernel is defined or specified_packages is defined

Note: I am aware and have used an extra variable such as "skip" to skip this task and use the when clause when: ansible_os_family == "RedHat" and skip is not defined but would prefer not have my users need to use an extra variable just to skip this default action.

I also am not using tags as I am gathering a list of packages before and after the upgrade to compare and report in the end so I wont be able to run those as they are local action commands. This is why I'm using one role with multiple tasks turned on and off via extended variables. I am open to any suggestion that rewrites the playbook in a more efficient way as I am sort of a noob.

Answer 1

It was such a simple answer!

The following works:

when: not (security is defined or kernel is defined or specified_packages is defined) and ansible_os_family == "RedHat"

Answer 2

As @techraf noted in comments, defined/undefined is a nasty test...

Refactor like this:

when:
  - ansible_os_family == "RedHat"
  - security|d('') != '' or kernel|d('') != '' or specified_packages|d('') != ''

Update. Reproducible example:

- hosts: localhost
  gather_facts: no
  tasks:
    - debug:
        msg: hello
      when:
        - '"RedHat" == "RedHat"'
        - security|d('') != '' or kernel|d('') != '' or specified_packages|d('') != ''

execution:

ansible-playbook -e kernel=true playbook.yml

PLAY [localhost] ***************************************************************

TASK [debug] *******************************************************************
ok: [localhost] => {
    "msg": "hello"
}

PLAY RECAP *********************************************************************
localhost                  : ok=1    changed=0    unreachable=0    failed=0

versions:

$ pip list | grep -iP 'ansible|jinja'
ansible (2.2.1.0)
Jinja2 (2.8)