Ansible - when statement task always return false value

Question

I've got 1 master node from which I would like to instal NewRelic agents remotely depedning on the OS I have on them. Some of them are Amazon 2 Amis and some Amazon 1 Ami. I put when statement in the Ansible Playbook's task in the following way:

- name: Enable repo for Amazon Linux 2/Red Hat 7v
  yum_repository:
    name: newrelic-infra
    description: NewRelic repo
    baseurl: https://download.newrelic.com/infrastructure_agent/linux/yum/el/7/$basearch
  when: (ansible_distribution == "Amazon" and ansible_distribution_version == "(Karoo)") or
        (ansible_distribution == "RedHat" and ansible_distribution_major_version == "7")

- name: Enable repo for Amazon Linux 1/Red Hat 6v
  yum_repository:
    name: newrelic-infra
    description: NewRelic repo
    baseurl: https://download.newrelic.com/infrastructure_agent/linux/yum/el/6/$basearch
  when: (ansible_distribution == "Amazon" and ansible_distribution_version == "2018.03") or
        (ansible_distribution == "RedHat" and ansible_distribution_major_version == "6")

I understand that when statement should check the if statement and proceed further. Nevertheless, whenever I run playbook I receive that if statement is false and it's skipping above tasks. What might be the root cause?

I've already checked on remote host ansible_distribution and ansible_distribution_version if strings match. I suppose it must be some syntax problem as I'm new in ansible. Thanks in advance.

Answer 1

Your statements look ok. If I create a test case from the sparse info you provided and what I can observe when gathering facts from my own hosts, I can detect old/recent distributions correctly using your conditions. See my example below.

I suggest you double check the data gathered from your host to understand why it doesn't match. The easiest way for that: from the same host your use to launch your playbook, run

ansible -i path/to/your_inventory.ini your_target_group_name -m setup -a "filter=ansible_distribution*"

Here is the test.yml playbook I wrote to test your (known-so-far) values and your conditions

---
- name: Statements for checking old/recent distribs
  hosts: localhost
  gather_facts: false

  vars:
    os_list:
      - ansible_distribution: "Amazon"
        ansible_distribution_version: "(Karoo)"
        ansible_distribution_major_version: "(Karoo)"
      - ansible_distribution: "Amazon"
        ansible_distribution_version: "2018.03"
        ansible_distribution_major_version: "2018"
      - ansible_distribution: "RedHat"
        ansible_distribution_version: "6.x"
        ansible_distribution_major_version: "6"
      - ansible_distribution: "RedHat"
        ansible_distribution_version: "7.x"
        ansible_distribution_major_version: "7"

  tasks:

    - name: Check conditions for recent distribs
      debug:
        msg: "This is a recent distrib"
      loop: "{{ os_list }}"
      loop_control:
        label: "{{ item.ansible_distribution }}-{{ item.ansible_distribution_version }}"
      when: (
              item.ansible_distribution == "Amazon"
              and
              item.ansible_distribution_version == "(Karoo)"
            )
            or
            (
              item.ansible_distribution == "RedHat"
              and
              item.ansible_distribution_major_version == "7"
            )

    - name: Check conditions for old distribs
      debug:
        msg: "This is an old distrib"
      loop: "{{ os_list }}"
      loop_control:
        label: "{{ item.ansible_distribution }}-{{ item.ansible_distribution_version }}"
      when: (
              item.ansible_distribution == "Amazon"
              and
              item.ansible_distribution_version == "2018.03"
            )
            or
            (
              item.ansible_distribution == "RedHat"
              and
              item.ansible_distribution_major_version == "6"
            )

And the result

PLAY [Statements for checking old/recent distribs] ************************************************************************************************************************************************************************

TASK [Check conditions for recent distribs] *******************************************************************************************************************************************************************************
ok: [localhost] => (item=Amazon-(Karoo)) => {
    "msg": "This is a recent distrib"
}
skipping: [localhost] => (item=Amazon-2018.03) 
skipping: [localhost] => (item=RedHat-6.x) 
ok: [localhost] => (item=RedHat-7.x) => {
    "msg": "This is a recent distrib"
}

TASK [Check conditions for old distribs] **********************************************************************************************************************************************************************************
skipping: [localhost] => (item=Amazon-(Karoo)) 
ok: [localhost] => (item=Amazon-2018.03) => {
    "msg": "This is an old distrib"
}
ok: [localhost] => (item=RedHat-6.x) => {
    "msg": "This is an old distrib"
}
skipping: [localhost] => (item=RedHat-7.x) 

PLAY RECAP ****************************************************************************************************************************************************************************************************************
localhost                  : ok=2    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0   

As you can see it does the job as expected. So either your data is not gathered correctly or your check the wrong values.

Note: When @Vladimir Botka asks for an MCVE in the comments, this is a typical example.