Checking Existence and Value of Variable - ansible

Question

I am building a play that requires the existence of a set of variables and also requires the variables to not equal bar. Below is an example of my definition of extra variables:
ansible.extra_vars = {
A: "foo",
B: "bar",
C: "foo",
...
}
When my play runs, I see the following when I print a debug message for each item:
(item=A) => {
"item": "A",
"var": {
"A": "foo"
}
}
When I try the below evaluation, I would expect a failure on B, however all tests pass:
- fail: msg="bar is not a valid variable value for this play"
with_items: required_vars
when: var.{{ item }} is not defined or (var.{{ item }} is defined and var.{{ item }} == "bar")
Does anyone have any suggestions on what I need to do to evaluate the value and cause a failure when bar is encountered?

Answer 1

extra_vars seems to be a dict, so you should use with_dict instead of with_items.
I'm not sure how exactly you did define extra_vars. When I define it in the playbook like below I get different output from debug. When I define it like that (ansible.extra_vars) in a group_vars file I do not get any data in the playbook at all.
Also, when I use my extra_vars dict together with with_items I get the following error:
fatal: [localhost] => with_items expects a list or a set
So there seems to be something strange about your extra_vars.
Here's my working example:
---
- hosts:
- localhost
gather_facts: no
vars:
extra_vars: {
A: "foo",
B: "bar",
C: "foo"
}
tasks:
- debug: var=extra_vars
- debug: msg="{{ item.key }}"
with_dict: extra_vars
when: item.value is not defined or (item.value is defined and item.value == "bar")
...
Output:
PLAY [localhost] **************************************************************
TASK: [debug var=extra_vars] **************************************************
ok: [localhost] => {
"var": {
"extra_vars": {
"A": "foo",
"B": "bar",
"C": "foo"
}
}
}
TASK: [debug msg="{{ item.key }}"] ********************************************
skipping: [localhost] => (item={'key': 'A', 'value': 'foo'})
skipping: [localhost] => (item={'key': 'C', 'value': 'foo'})
ok: [localhost] => (item={'key': 'B', 'value': 'bar'}) => {
"item": {
"key": "B",
"value": "bar"
},
"msg": "B"
}
PLAY RECAP ********************************************************************
localhost : ok=2 changed=0 unreachable=0 failed=0