Ansible Role for Generating Subuids & Subgids

Creates subuid & subgid mappings for users.

Inspired from this blog article https://eengstrom.github.io/musings/generate-non-contiguous-subuid-subgid-maps-for-rootless-podman

Install

roles/requirements.yml

---
roles:
  - name: subuid_subgid
    version: main
    src: git@github.com:rwxd/ansible-role-subuid_subgid.git
    scm: git

ansible.cfg

[defaults]
roles_path=./roles

Get requirements with ansible-galaxy role install -r roles/requirements.yml

Usage

A subid_users variable is required e.g.:

- name: Set users
  set_fact:
    subid_users:
      - peter
      - james

- name: Generate subuids & subgids
  include_role:
    name: subuid_subgid

/etc/subuid will contain

peter:65929216:65536
james:65470464:65536

/etc/subgid will contain

peter:65929216:65536
james:65470464:65536

Configure the size of the bitshift

UID's can be not larger than 2^32. So if you have large UID's you may want to use a smaller bitshift. https://wiki.gentoo.org/wiki/Subuid_subgid https://bit-calculator.com/bit-shift-calculator

- name: Generate subuids & subgids
  include_role:
    name: subuid_subgid
  vars:
    subuid_bitshift: 16
    subgid_bitshift: 16