Lists dangling docker volumes and their sizes

dckr-volumes

#!/usr/bin/env bash
set -euo pipefail

# loop through each volume and calculate its size
function list_vols_and_sizes() {
    VOLUMES=$1
    for volume_name in $VOLUMES; do
        SIZE=$(sudo du -sh "$DOCKER_VOLUME_DIR/${volume_name}/_data" 2>/dev/null | awk '{print $1}')
        echo "${volume_name}, $SIZE"
    done
}

# List dangling Docker volumes and their sizes.
function main() {

    # directory where Docker volumes are stored.
    DOCKER_VOLUME_DIR="$(docker info --format '{{.DockerRootDir}}')/volumes"

    # list all Docker volumes
    VOLUMES=$(docker volume ls -qf dangling=true)

    echo "Found $(echo "$VOLUMES" | wc -w) dangling volumes"
    echo "I need sudo to list volume sizes"
    sudo -v

    echo "Listing dangling volumes and their sizes..."
    printf "%-30s %s\n" "VOLUME NAME" "SIZE"
    list_vols_and_sizes "$VOLUMES" | sort -t, -k2 -h | column -t -s,

}

main