docker-prune.sh.template

#!/bin/bash
set -o errexit -o pipefail -o noclobber -o nounset

DOCKER_EXE="%DOCKER%"

exec >> /tmp/docker-prune-${USER:-$LOGNAME}.log
exec 2>&1
echo "Prune script running on $(date)"

# TODO: Instead of hard coding, we may also want to configure these upon script installation
export XDG_RUNTIME_DIR="/run/user/$UID"
export DOCKER_HOST="unix:///run/user/$UID/docker.sock"

#
# Prunes dangling and old (> 1 month) Docker images and other unused data.
#

# Delete old images (will not delete images that are still used by existing containers or child images)
echo "Pruning images older than 1 month..."
! "$DOCKER_EXE" images 2>&1 | \
    awk -F '[[:space:]][[:space:]]+' '$4 ~ /[5-9] weeks ago/ || $4 ~ /[1-9] months ago/ {print $3}' | \
    xargs "$DOCKER_EXE" rmi

# Prune dangling images
echo "Pruning dangling images..."
! "$DOCKER_EXE" image prune --force

# Prune other unused system data
echo "Pruning other unused data..."
! "$DOCKER_EXE" system prune --force