Jinja array collection in SaltStack
, configuration | saltstack | apache
Saltstack states allow for explicit configuration management, but the real power of saltstack is obtained when states are combined with pillar data and even further with grain data. I needed to combined multiple pillar environment elements into one collection in a apache state sls file. 
{% set ENVIRONMENT_A = pillar['environment_a'] %}

{% set ENV_COLLECTION = [] %}

{% if pillar['environment_b'] is defined %}
{% do ENV_COLLECTION.append( "NICE_ENV_VAR " ~ pillar['environment_b']['top_notch_env_var'] ) %}
{% do ENV_COLLECTION.append( "MORE_ENV " ~ pillar['environment_b']['even_better_env'] ) %}
{% endif %}

{% for env_key, env_value in ENVIRONMENT_A.items() %}
{% do ENV_COLLECTION.append( env_key ~ " " ~ env_value ) %}
{% endfor %}

/etc/httpd/conf.d/site.conf:
  apache.configfile:
    - config:
      - VirtualHost:
          - this: '*:443'
              {% if ENV_COLLECTION | length %}
              SetEnv:
                {% for env_part in ENV_COLLECTION %}
                - {{ env_part }}
                {% endfor %}
              {% endif %}