Strange behavior in group_by module with 'with_items'

Archives Ansible Project
1

Hi,

I have a couple of hosts that have a ‘profiles’ variable that contains a list of, well, profiles that I want to apply. I want to use group_by to turn those into groups. However, it is not working. (I am doing this on the current devel branch, by the way.)

This test case isolates the issue:

hosts

2

I’m not positive group_by can be used with with_items.

I think we may have proposed making this raise an error, which seems easy to do if this is the case.

If you feel you can boil this down to a minimal reproducer example please file a bug in github and we can take a look. I’d probably just do it with a hard coded list for starters, just to make sure variables have nothing to do with it (as it would provide more information if they did).

Sidenote - it’s very unusual to put variables below your tasks section. I’d suggest not doing that as it makes playbooks less readable.

3

This seems to be doing what you are telling it to do to me.

Pseudocode:

For every host in the inventory
  For every host-inventoryname
    Add the host to the host-inventoryname group.

The one part I'm not sure about is whether host-inventoryname is being defined once and they are only being put in one group or if they are being put in multiple groups each.

Adam

4

I'm not positive group_by can be used with with_items.

I think we may have proposed making this raise an error, which seems easy to
do if this is the case.

Well, using a fixed list does work, adding every item as a group. It's
when a fact (host-specific variable) is used that a problem occurs:
the value for the first host is used for all hosts.

If you feel you can boil this down to a minimal reproducer example please
file a bug in github and we can take a look. I'd probably just do it with
a hard coded list for starters, just to make sure variables have nothing to
do with it (as it would provide more information if they did).

I have removed the test_items variable and submitted an issue:
https://github.com/ansible/ansible/issues/7540

Sidenote - it's very unusual to put variables below your tasks section. I'd
suggest not doing that as it makes playbooks less readable.

Yeah, that was probably because I went through stripped down a role to
a playbook in alphabetical order. :slight_smile:

5

“It’s
when a fact (host-specific variable) is used that a problem occurs:
the value for the first host is used for all hosts.”

group_by was definitely intended to work with fact based variables, in fact, this is the most common pattern:

  • group_by: key=os-{{ ansible_os_family }}

We’ll have to look into the looping scope question.

Ticket is filed here for those interested: https://github.com/ansible/ansible/issues/7540