Using compound AWS tags from dynamic inventory on a jinja template

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1

Hello everyone,

I’m trying to use a combine call to AWS tags within a jinja template so I can select nodes for a cassandra cluster.

  • seeds: {% set comma = joiner(“,”) %}
    {% for server in groups[ ‘tag_env_{{ env }}:&tag_role_{{ role }}’ ] -%}
    {{ comma() }}{{ hostvars[server].ansible_eth0.ipv4.address }}
    {%- endfor %}

Where {{ env }} and {{ role }} are passed as extra-varas when running the playbook but seems that is not being reconginzed as a valid, here is the error:

{“src”: “templates/cassandra.yaml.j2”}, “module_name”: “template”}, “msg”: “AnsibleUndefinedVariable: ‘dict object’ has no attribute ‘tag_env_{{ env }}:&tag_role_{{ role }}’”

But I use that same combination to select initially the hosts on which to run the playbook as in:

hosts: tag_env_{{ env }}:&tag_role_{{ role }}

Any ideas on why or what may be failing with the jinja template?

Thank you

2

OK, so I’ve lernt that host variables don’t work in Jinja2 templates.

Any idea on how I can get arround this?

3

host variables DO work in jinja template, host patterns do not. Just use set theory filters to do the intersection.

Also you can save many moustaches as {% %} already implies variable interpolation.

  • seeds: {% set comma = joiner(“,”) %}
    {% for server in groups[ ‘tag_env_’ + env]|intersection(groups[‘tag_role_’ + role]) -%}
    {{ comma() }}{{ hostvars[server].ansible_eth0.ipv4.address }}
    {%- endfor %}