Using an environment variable in a state file

Calling salt-call with environment variables

MYENVVAR="world" salt-call state.template test.sls

test.sls

Create a file with contents from an environment variable:
  file.managed:
    - name: /tmp/hello
    - contents: {{ salt['environ.get']('MYENVVAR') }}

test.sls with error checking

{% set myenvvar = salt['environ.get']('MYENVVAR') %}
{% if myenvvar %}

Create a file with contents from an environment variable:
  file.managed:
    - name: /tmp/hello
    - contents: {{ salt['environ.get']('MYENVVAR') }}

{% else %}

Fail - no environment passed in:
  test:
    - fail_without_changes

{% endif %}

This approach won't work in 2014.1.x and before. To do this in older releases you can do
{{ salt['cmd.run']('echo $MYENVVAR') }}