turning a simple formula into an iterator

i'm working from the vsftpd formula...

Starting from:

  https://github.com/saltstack-formulas/vsftpd-formula

vsftpd supports per-user configurations, which the formula doesn't yet cover, so I'm trying to 
extend it. I'm also really new at this so the basic toolkit is still a challenge for me.

vsftpd.conf mostly consists of a list of key = value pairs. The template that produces it
is mostly a list of tuples, type_of_key("key", "default").

Per-user configuration looks just like main server configuration, more or less; alongside
the main config file, there are per-user config files:

  /etc/vsftpd/vsftpd_user_conf/[username]

...where each 'username' file conforms to the same format as the main server config file,
with the same list of options. (A lot don't make sense per-user obviously, but that's the gist.)

I'm trying to write a new template by copying and adjusting the existing one. I'm hung up on 
what seems like a simple enough issue, but I don't know how to express it well enough to hunt 
down the approach.

The original formula populates its main config file wit a pillar:

  vsftpd:
    foo: 23
    bar: whatever

In my pillar, I have:

  vsftpd_user_conf:
    tom:
      - foo: 23
      - bar: sometimes
    dick:
      - foo: 42
      - bar: never
  
My goal is to produce files named for the first layer of elements
(tom, dick, etc.) where each files is made from a template pupulated
with those elements. You get the idea.

I've got the formula extended to the point where it produces the per-user
files under /etc/vsftpd/vsftpd_user_conf/[tom, dick, george, ringo], and 
I've got a pillar of the form:

  vsftpd_user_configs:
    tom:
      - foo: 23
      - bar: this
    dick:
      - foo: 42
      - bar: that
    [...]

...but I haven't figured out the right syntax for fitting a layer
into the template so that walks that list of accounts.

This is obviously wrong:

  {%- for user, conf in pillar.get('vsftpd_user_config', {}).items() if user.absent is not defined or not user.absent %}

I've had better attempts but they're lost in a sea of edits and deletes.

Get the idea? Clue me up?