feature request: add salt tops External Nodes Classifier

[Sjd-Risca]

It would be nice if pillarstack could have a top module for generating the top file.

See here for detailed examples.

Here is what varstack does: /usr/lib/python2.7/dist-packages/salt/tops/varstack.py

[Sjd-Risca]

It could be a nice idea.

At current state I usually circumvent such issue with the following salt/top.sls file:

{%- set base = salt.pillar.get('tops:base', []) %}
{%- if base|length > 0 %}
base:
    '*':
        {%- for role in base %}
        - {{ role }}
        {%- endfor %}
{% endif %}
{%- set dev = salt.pillar.get('tops:dev', []) %}
{%- if dev|length > 0 %}
dev:
    '*':
        {%- for role in dev %}
        - {{ role }}
        {%- endfor %}
{% endif %}

Whereas the pillar render to something like:

tops:
  base:
    - user
    - apache
user:
  ...
apache:
  ...