Variable undefined after set_fact

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1

I am either missing something simple or ran into a bug.

I have a playbook that passes variable to a role as follows:

roles:

  • { role: test_role, var1: ‘some string’, var2: “{{ some_var }}”, var3: “{{ some_var2 }}” }

Now both some_var and some_var2 are set (verified with a debug before this)

in the role I have the following:

  • set_fact: var2 = “something”
    when: var2 is not defined

  • set_fact: var3 = “something”
    when: var3 is not defined

  • debug: “msg=’ {{ var3 is not defined }} '”

  • debug: “msg=‘{{ var2 }} {{ var3 }}’”

Now the output is as follows

TASK: [test_role | set_fact var2 = something] ***
skipping: [10.0.0.1]

TASK: [test_role | set_fact var3 = something] ***
ok: [10.0.0.1]

TASK: [test_role | debug msg=’ True '] ***************************************
ok: [10.0.0.1] => {
“item”: “”,
“msg”: " True "
}

TASK: [test_role | debug msg=‘{{var2}} {{var3}}’] ********
fatal: [10.0.0.1] => One or more undefined variables: ‘var3’ is undefined

So as you can see the var2 is passed through and is defined and so the set_fact is skipped.
But var3 is not passed so the set_fact runs but it is still undefined afterwards.

I have tried changing the order of the variables in the playbook, renaming the variable and I always get the same problem. Anyone know what I’m missing?

Thanks,

2

So I found part of the problem.

First the set_fact only seemed to work when using the second format in the documentation

  • set_fact:
    var2: “something”
    when: var2 is not defined

second I found that if the set_fact runs in a role once and you run that role multiple times with different variable the set_fact will hold over until it is run at that level again.

For example:

roles:

  • { role: test_role, var1: ‘some string’, var2: “{{ some_var }}” }
  • { role: test_role, var1: ‘some string’, var2: “{{ some_var }}”, var3: “{{ some_var2 }}” }

In the first run var3 gets set to ‘something’
on the second run even thought I tell it to set var3 to {{some_var2}} it seems to remember that at that level it was previously set to ‘something’ and that local setting takes president as if it was set that time around as well (even though it isn’t)

3

Yes, set_fact sets the fact in the hostvars cache, so that it is available from that point on. You may want to look at using defaults/main.yml rather than set_fact to accomplish what you want.

4

  • set_fact: var2 = “something”
    when: var2 is not defined

  • set_fact: var3 = “something”
    when: var3 is not defined

Try this without spaces around the ‘=’ .