Variables and serial: keyword

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1

I’ve been struggling with passing variable to serial for the whole day.

All I need is to pass group’s length, I’ve tried
serial: "{{ groups['appserver']|length }}"

and got a runtime error.

Finally I come up with this code:

serial: "{{ lookup('group_size', 'appserver') }}"

, where group_size is a custom lookup plugin.

Now I have another problem - how can I get access to inventory instance inside lookup plugin? I don’t understand API design - all plugins have “runner” instance in constructor except LookupModule.

So my questions are:

  • can I parameterize serial?
  • can I access inventory inside LookupModule?

Thank you!

2

yes
no

parameters to serial cannot depend on inventory as it gets read AFTER
the play is evaluated (serial value is assigned). So use extra vars to
set serial dynamically.