include_vars and hash-behaviour

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1

Hello list,

I have encountered some not expected results when i tried to include (with include_vars) multiple var files in the beginning of a play.

I normally use the “merge” hash behavior (ansible.cfg) because it seems more natural to me: i usually have highly nested variable dicts
and i wish to add or override just parts of them based on the group/host hierarchy.

Now, i tried to include some variables in the beginning of a play (at “pre_tasks” phase, but i don’t thing it’s relevant), to override some
parts of existing dicts with piece of information regarding other present hosts (e.g. IPs for standby servers). It didn’t succeed.

Consider the following example:

# vars file: play_vars/baz-a.yml
baz:
a: 1

# vars file: play_vars/baz-b.yml
baz:
b: 2

---
# playbook: play.yml
- hosts: all

pre_tasks:
- include_vars: play_vars/baz-a.yml
- include_vars: play_vars/baz-b.yml

tasks:
- debug: var=baz

When playing play.yml, i get: “baz”: {“b”: 2} while expecting “baz”: {“a”:1, “b”:2}.
Is this normal? Note, this is happening under hash_behavior=merge.

2

Hello,

any answer to this question?

3

Have a look at hash_behaviour in ansible.cfg and set it to merge. But be aware that it’s usually sign of bad design.

4

Hello Adam,

I allready have set it to “merge”, actually that’s the reason i posted this question (because it doesn’t seem to merge).
Have you tried the example above? I tested it under ansible==1.8.4. Maybe i am missing something obvious.

5

there was a but in 1.8 with hash_merge, have you tried in 1.9?

6

Hello Brian,

I just tested the above with a freshly installed ansible==1.9.1, and the problem seems to be still here.
I played the example posted above accompanied with a simple ansible.cfg:

[defaults]
hash_behaviour = merge

Cant you reproduce it?

7

So I looked and include_vars works by returning ansible_facts which
bypasses, on purpose, hash merging as facts should overwrite
themselves. The way this currently CAN work ... its not clear how we
can use the merge,I'll add notes to the docs that include_vars always
overwrites.

8

Ok, i understand, seems that include_vars works like set_fact in this place.

Thanks, Brian