Custom sort list based on another

Question

I'm trying to sort a list of files based on a desired extension preference. Let's say I have a list that looks like:

- name: Declare all assets
  ansible.builtin.set_fact:
    asset_list:
      - artifact_amd64.tar.gz
      - artifact_amd64.tar.gz.sbom
      - artifact_arm64.tar.gz
      - artifact.deb
      - artifact.appimage
      - artifact_amd64
      - artifact_amd64.sha256sum

Now, I'd like to get sort them in some order which could be changed by prompt, say: ['deb', 'appimage', 'tar.gz', '']. In this case '' means no extension, which in this case means it's a linux executable. Regarding the files that don't match the extension, I'm not intereseted in them, I'd prefer them to be removed.

Is this possible to do without writing a custom filter? I had the idea to prepend the extensions to the items with something like: map('regex_replace', '^(.*\\.)(deb|appimage|tar\\.gz)$', '\\2 \\1\\2') but I would still need to prepend a number or something to pass it through the regular ansible sort before trying to remove it to get the final filename. The entire thing looks very complicated and hard to read in that case and I don't have a good solution for no extension.

Answer 1

Given the lists of the files and the extensions

    asset_list:
      - artifact_amd64.tar.gz
      - artifact_amd64.tar.gz.sbom
      - artifact_arm64.tar.gz
      - artifact.deb
      - artifact.appimage
      - artifact_amd64
      - artifact_amd64.sha256sum
    asset_order: [deb, appimage, tar.gz]

Reverse the items

    asset_list_reverse: "{{ asset_list | map('reverse') }}"
    asset_order_reverse: "{{ asset_order | map('reverse') }}"

Use the fact that the test match:

succeeds if it finds the pattern at the beginning of the string

and create the ordered list of files with extensions

  asset_list_order: |
    {% filter flatten %}
    [{% for ext in asset_order_reverse %}
    {{ asset_list_reverse | select('match', ext) | map('reverse') }},
    {% endfor %}]
    {% endfilter %}

gives

  asset_list_order:
  - artifact.deb
  - artifact.appimage
  - artifact_amd64.tar.gz
  - artifact_arm64.tar.gz

Create a list of executables

  asset_list_exe: "{{ asset_list | reject('search', '\\.') }}"

gives

  asset_list_exe:
  - artifact_amd64

Add the lists

  result: "{{ asset_list_order + asset_list_exe }}"

gives

  result:
  - artifact.deb
  - artifact.appimage
  - artifact_amd64.tar.gz
  - artifact_arm64.tar.gz
  - artifact_amd64

---

Notes

1. Example of a complete playbook for testing

- hosts: localhost

  vars:

    asset_list:
      - artifact_amd64.tar.gz
      - artifact_amd64.tar.gz.sbom
      - artifact_arm64.tar.gz
      - artifact.deb
      - artifact.appimage
      - artifact_amd64
      - artifact_amd64.sha256sum
    asset_list_reverse: "{{ asset_list | map('reverse') }}"

    asset_order: [deb, appimage, tar.gz]
    asset_order_reverse: "{{ asset_order | map('reverse') }}"

    asset_list_order: |
      {% filter flatten %}
      [{% for ext in asset_order_reverse %}
      {{ asset_list_reverse | select('match', ext) | map('reverse') }},
      {% endfor %}]
      {% endfilter %}
    asset_list_exe: "{{ asset_list | reject('search', '\\.') }}"
    result: "{{ asset_list_order + asset_list_exe }}"

  tasks:

    - debug:
        var: asset_list_order
    - debug:
        var: asset_list_exe
    - debug:
        var: result

---

2. If you want to put the empty string into the list, for example,

  asset_order: [deb, appimage, tar.gz, '']

remove it from the list of the reversed extensions

  asset_order_reverse: "{{ asset_order | select | map('reverse') }}"

and test it when assembling the result

  result: "{{ ('' in asset_order) |
              ternary(asset_list_order + asset_list_exe,
                      asset_list_order) }}"

---

3. The next option is to create the complete list in Jinja. This keeps the order of the extensions including the executables. The example of a complete playbook for testing

- hosts: localhost

  vars:

    asset_list:
      - artifact_amd64.tar.gz
      - artifact_amd64.tar.gz.sbom
      - artifact_arm64.tar.gz
      - artifact.deb
      - artifact.appimage
      - artifact_amd64
      - artifact_amd64.sha256sum
    asset_order: [deb, '', appimage, tar.gz]

    asset_list_reverse: "{{ asset_list | map('reverse') }}"
    asset_order_reverse: "{{ asset_order | map('reverse') }}"

    result: |
      [{% for ext in asset_order_reverse %}
      {% if ext|length > 0 %}
      {{ asset_list_reverse | select('match', ext) | map('reverse') }},
      {% else %}
      {{ asset_list | reject('search', '\.') }},
      {% endif %}
      {% endfor %}]

  tasks:

    - debug:
        var: result | flatten

gives

  result | flatten:
  - artifact.deb
  - artifact_amd64
  - artifact.appimage
  - artifact_amd64.tar.gz
  - artifact_arm64.tar.gz