Test Jinja Not working, just want a list of server IP's

Log

The result is a blank file and this error when running:

salt 'lb*' state.apply test

lb-dev-1:
    ----------
    file_|-/opt/local/etc/nginx/upstream.conf_|-/opt/local/etc/nginx/upstream.conf_|-managed:
        ----------
        __run_num__:
            0
        changes:
            ----------
        comment:
            Unable to manage file: Jinja variable 'str object' has no attribute 'items'
        duration:
            23.038
        name:
            /opt/local/etc/nginx/upstream.conf
        result:
            False
        start_time:
            18:38:16.946461

test.sls

/opt/local/etc/nginx/upstream.conf:                                                     
  file.managed:                                                                         
    - source: salt://lb/upstream.conf.jin                            
    - template: jinja

upstream.conf.jin

{% for server,ip in salt['mine.get']('*', 'network.interfaces', ['eth0']).items() %}
  server {{ server }} {{ ip }}
{% endfor %}

I took this jijna example from the docs, but not working: http://docs.saltstack.com/en/latest/topics/reactor/#passing-event-data-to-minions-or-orchestrate-as-pillar

updated with corrected .jin