ansible can't get inventory_hostname

Question

I'm trying to get the short name of a server being worked on.

I have this in jinja2:

ServerAlias graphite.{{ hostvars[inventory_hostname] }}
ServerAlias graphite.{{ hostvars[inventory_hostname] }}.{{dc}}.{{subnet}}

The above just spills the whole glob of facts instead of just the short name.

This is what the hosts.yaml looks like:

graphite.experimental.com dc=lv1 subnet=coupons.lan

Answer 1

What you want to use is just {{ inventory_hostname }} (or {{ inventory_hostname_short }} for the short name).

The hostvars object is a way to access the variables of every host that Ansible knows about. So hostvars[inventory_hostname] will give you the object containing all known facts about the current host, hostvars['foo'] will give you the object containing all the known facts about the host 'foo', etc.

Suppose you have a group of hosts called 'db_servers' and you wanted to generate a list of the IP addresses of all those hosts in a template. Here's how you would do that:

{% for host in groups['db_servers'] %}
   {{ hostvars[host]['ansible_eth0']['ipv4']['address'] }}
{% endfor %}