Ensure base device size is not changed until needed

LowLevel 2Automateddocker

Description

Increasing the base device size (dm.basesize) can affect all images and containers and should only be done when needed. Compliant when no dm.basesize storage option is set on the dockerd command line or in /etc/docker/daemon.json.

How it is checked

Audit method: Shell command

shell

args=$(ps -eo args 2>/dev/null) || exit 1; s=$(printf '%s\n' "$args" | grep '[d]ockerd'; cat /etc/docker/daemon.json 2>/dev/null); printf '%s\n' "$s" | grep -q 'dm\.basesize' && echo noncompliant || echo compliant

Expected output: compliant

How it is fixed

Fix method: Guidance or infrastructure patch

Remove dm.basesize from "storage-opts" in /etc/docker/daemon.json and from --storage-opt start-up flags unless it is genuinely needed, then restart the Docker daemon.

Properties

Operating systems: Any
Tags: dockerdaemonstorage
Reference: CIS Docker Benchmark v1.9.0 - 2.12 Ensure base device size is not changed until needed

Check this host

Run this on a machine you are allowed to audit. The scan is read-only.

shell

tmaegis scan --target docker --level 2