Systemd #

systemd-cgls: Get a pstree-like output of all processes, with their associated Systemd units, from which we can know the session ID of any logged-in user and enforce resource control.
systemd-run: Run a command in a on-fly Systemd unit:

# Enforcing memory limit via CGroup, run with dynamic non-root user
systemd-run -t -p DynamicUser=yes \
    -p MemoryMax=600M \
    /bin/sh -c "cd /root; ./test.sh"

DBus interface #

Get DBus interface URI:

sudo busctl tree org.freedesktop.systemd1

With a URI obtained from above: /org/freedesktop/systemd1/unit/session_2dc18_2escope, we can get its current property list.

sudo busctl introspect org.freedesktop.systemd1 /org/freedesktop/systemd1/unit/session_2dc18_2escope

Set CGroup resource limit:

# Set CPUQuota = 10%
sudo gdbus call --system --dest org.freedesktop.systemd1 --object-path /org/freedesktop/systemd1/unit/session_2dc20_2escope \
    --method org.freedesktop.systemd1.Unit.SetProperties true "[('CPUQuotaPerSecUSec', <@t 100000>)]"

# Set MemoryMax = 4G
sudo gdbus call --system --dest org.freedesktop.systemd1 --object-path /org/freedesktop/systemd1/unit/session_2dc20_2escope \
    --method org.freedesktop.systemd1.Unit.SetProperties true "[('MemoryMax', <@t 4000000000>)]"

Services accessible from DBus:

gdbus call --system --dest org.freedesktop.DBus --object-path /org/freedesktop/DBus --method org.freedesktop.DBus.ListNames

Systemd #

DBus interface #

Also see #