This isn't working for me -hosts: {{ hostvars['localhost']['mylist'] }} : hostvars is undefined

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I’m trying to dynamically build the group of hosts that will be used in a play. I’m doing this within a hosts: localhost play. However hostvars seems to be undefined when evaluating the - hosts: line. Suggestions?

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Not being helpful, but re-enforcing the (mis)behaviour using Ansible 2.0.2

For my case I was calling sts_assume_role on localhost (hosts:localhost) for get a different aws id, key and token seeing it’s only an api call, then setting then using set_facts to set variables. In another play in the same playbook I called it against another host (host:foobar) and tried to reference hostvars[‘localhost’][‘aws_cred_id’] .The variable is not defined was my result.

I managed to work around it just by calling the sts_assume_role task on the remote host.

Is this the expected behaviour? I thought magic variables could be used for this? is it only for retrieving group file variables?

http://docs.ansible.com/ansible/playbooks_variables.html#magic-variables-and-how-to-access-information-about-other-hosts

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Thanks Steve. This sounds very much like what I’m trying to do. In my case I want to enforce some rules, defaults and aliases on a host group selected via --extra-vars. Thought I would do that with a localhost Play and set_facts, as you described. If this is the wrong approach I’m happy to get steered in the right direction. I started looking at dynamic inventory but this seems to be overkill for my current need. It also feels like the wrong direction. Another option I’m considering is a jinja2 function. Eg. - hosts: "{{ myj2func() }}

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Just want to make sure you’ve considered add_host
http://docs.ansible.com/ansible/add_host_module.html

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Hmm, looks promising but seems to be the opposite of what I want. I would want to create a new group ID that references an existing group. Another solution would be to dynamically create an extra-var or similar root/global scoped variable. Is there anything like set_extra_var with behaviour similar to set_fact? This is pushing back toward the functionality that works:

  • hosts: “{{ extra_var }}” I tested this and it works
  • hosts: “{{ dynamically_created_extra_var }}” Does this exist?