# polymac filter for Ansible

**URL:** <https://forum.ansible.com/t/polymac-filter-for-ansible/36123>\
**Category:** Ansible Project\
**Created:** [December 16, 2021, 6:44pm UTC](https://forum.ansible.com/t/polymac-filter-for-ansible/36123 "2021-12-16T18:44:49Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![utoddl](https://sea1.discourse-cdn.com/ansible/user_avatar/forum.ansible.com/utoddl/32/249_2.png) [@utoddl](https://forum.ansible.com/u/utoddl)\
**Post date:** [December 16, 2021, 6:44pm UTC](https://forum.ansible.com/t/polymac-filter-for-ansible/36123/1 "2021-12-16T18:44:49Z")

</div>

In the Spirit of

- the Season,
- this group (“…to share information about cool things done with Ansible…”), and
- DRY (“don’t repeat yourself”),

I’m happy to present to you [polymac](https://gist.github.com/utoddl/fc303d5b9dcad58871d2956cfed0aa68): a filter for macro expansion of Ansible data with variable substitution. An example apropos for the season:

```auto
- name: Seasonal example of the "polymac" filter
  debug: msg="{{ song | polymac | to_nice_yaml(indent=8, width=1337)}}
  vars:
    song:
      title: The Twelve Days of Christmas
      lyrics:
        polymac:
          - DayOf: "day of Christmas my true love gave to me\n"
            1st: "a partridge in a pair tree."
            2nd: "two turtle doves,\nand %1st%"
            3rd: "three French hens,\n%2nd%"
            4th: "four calling birds,\n%3rd%"
            5th: "five golden rings,\n%4th%"
            6th: "six geese a laying,\n%5th%"
            7th: "seven swans a swimming,\n%6th%"
            8th: "eight maids a milking,\n%7th%"
            9th: "nine ladies dancing,\n%8th%"
            10th: "ten lords a leaping,\n%9th%"
            11th: "eleven pipers piping,\n%10th%"
            12th: "twelve drummers drumming,\n%11th%"
          - "On the first %DayOf% %1st%"
          - "On the second %DayOf% %2nd%"
          - "On the third %DayOf% %3rd%"
          - "On the fourth %DayOf% %4th%"
          - "On the fifth %DayOf% %5th%"
          - "On the sixth %DayOf% %6th%"
          - "On the seventh %DayOf% %7th%"
          - "On the eighth %DayOf% %8th%"
          - "On the nineth %DayOf% %9th%"
          - "On the tenth %DayOf% %10th%"
          - "On the eleventh %DayOf% %11th%"
          - "On the twelfth %DayOf% %12th%"

```

produces

```auto
  song:
    title: The Twelve Days of Christmas
    lyrics:
      - |
        On the first day of Christmas my true love gave to me
        a partridge in a pair tree.
      - |
        On the second day of Christmas my true love gave to me
        two turtle doves,
        and a partridge in a pair tree.
# … skipping to the last verse; you get the idea …
      - |
        On the twelfth day of Christmas my true love gave to me
        twelve drummers drumming,
        eleven pipers piping,
        ten lords a leaping,
        nine ladies dancing,
        eight maids a milking,
        seven swans a swimming,
        six geese a laying,
        five golden rings,
        four calling birds,
        three French hens,
        two turtle doves,
        and a partridge in a pair tree.

```

There are additional made up examples in the in-line docs at the top of the file. I’ll include one more here from our actual production configs.

```auto
  - name: Example 2
    debug: msg="{{ example2 | polymac(debug=False) |to_nice_yaml(indent=8, width=1337) }}"
    vars:
      example2:
      - name: &name Merge Request Notifier
        src: merge-requests.py
        polymac:
        - - title: *name
            sched: "weekday business hours" # 19,39,59 7-16 * *1-5 
            minute: "19,39,59"
            hour: "7-16"
            weekday: "1-5"
          - title: *name
            sched: "weekday evenings" # 2 18,20 * *1-5
            minute: "2"
            hour: "18,20"
            weekday: "1-5"
          - title: *name
            sched: "weekends" # 2 7,13,19 * *0,6
            minute: "2"
            hour: "7,13,19"
            weekday: "0,6"
        - cron:
            name: '%title% -- %sched%'
            environment: # Required b/c Slack API is off-site
              http_proxy: "<redacted>"
              https_proxy: "<redacted>"
              no_proxy: "<redacted>"
            minute: '%minute%'
            hour: '%hour%'
            weekday: '%weekday%'

```

produces the following data structure which one of our roles uses to install a script and create several cron jobs for that script:

```auto
- cron:
    environment:
      http_proxy: <redacted>
      https_proxy: <redacted>
      no_proxy: <redacted>
    hour: 7-16
    minute: 19,39,59
    name: Merge Request Notifier -- weekday business hours
    weekday: 1-5
  name: Merge Request Notifier
  src: merge-requests.py
- cron:
    environment:
      http_proxy: <redacted>
      https_proxy: <redacted>
      no_proxy: <redacted>
    hour: 18,20
    minute: '2'
    name: Merge Request Notifier -- weekday evenings
    weekday: 1-5
  name: Merge Request Notifier
  src: merge-requests.py
- cron:
    environment:
      http_proxy: <redacted>
      https_proxy: <redacted>
      no_proxy: <redacted>
    hour: 7,13,19
    minute: '2'
    name: Merge Request Notifier -- weekends
    weekday: 0,6
  name: Merge Request Notifier
  src: merge-requests.py

```

To install the polymac filter, download it from the link above and put it in your role’s `filter_plugins` directory.

Enjoy,

​