userns.sls subuid subgid podman-compatible saltstack formula

userns.sls

# Only supported on Ubuntu 18.04 and newer
{% if grains.osmajorrelease >= 18 %}

userns.uidmap:
    file.touch:
        - name: /etc/subuid
        - unless: test -f /etc/subuid

userns.gidmap:
    file.touch:
        - name: /etc/subgid
        - unless: test -f /etc/subgid

{% set users = salt.user.getent() %}
{% set ns = namespace( count = 65536, start = 0) %}
{% for user in users %}
{% if user.uid >= 1000 and user.uid < 65534 %}
{% set ns.start = ns.start + 100000 %}
{% set ns.stop = ns.start + ns.count %}
userns.{{ user.name }}:
    cmd.run:
        - name: usermod --add-subuids {{ ns.start }}-{{ ns.stop }} --add-subgids {{ ns.start }}-{{ ns.stop }} {{ user.name }}
        - unless: "grep -q '^{{ user.name }}:' /etc/subuid /etc/subgid 2>/dev/null"
        - require:
            - userns.uidmap
            - userns.gidmap
{% endif %}
{% endfor %}

{% endif %}