Use minion targeting within Jinja templates

Question

SaltStack allows for precise targeting of minions on the command-line, e.g.:

salt 'prefix*' grains.items
      ^^^^^^^

Is there some way to use the same way of targeting minions within Jinja templates? I'd like to iterate over hosts targeted by the given matcher, e.g:

{% for minion in salt.minions['prefix*'] %}
                               ^^^^^^^

Unfortunately I didn't find anything in the official help on using Jinja.

Answer 1

From the additional comments you posted, it seems you are looking for the Salt mine functionality. Using Salt mine we can collect data from minions (to master), and use the data on (usually) other minions.

Salt Mine can be enabled in minion configuration file, or minion's pillar, but format is same.

For the sake of example:

Consider 4 minions as below:

web1.example.local
db1.example.local
db2.example.local
db3.example.local

Now in the pillar file (db.sls) for the dbX minions, I have defined two Salt modules as Mine functions to get hostname and additionally IP address.

mine_functions:
  network.get_hostname: []
  network.ip_addrs: []

Note that the Mine and Pillar might have to be updated (mine.update)/refreshed (saltutil.refresh_pillar) for this change to reflect.

Now any of the above Mine functions can be referenced by the Mine module's get function. Minions can be targeted in the usual way - wildcard, grains, compound, etc.

Sample example.conf.j2 template where I render the minion id and hostname.

{% for minion_id, hostname in salt['mine.get']('db*', 'network.get_hostname') | dictsort() %}
Minion id {{ minion_id }} has hostname {{ hostname }}
{% endfor %}

This template can be rendered on the web1.example.local with below state:

create-example-conf:
  file.managed:
    - name: /tmp/example.conf
    - source: salt://example.conf.j2
    - mode: 0664
    - template: jinja

This will result in /tmp/example.conf file with the lines showing minion_id and hostname.