Remove docker volumes that have not been used for a time

docker-volumes-clean.sh

#!/bin/bash -e

### Author:  Alex Duzsardi
### Twitter: @aduzsardi
### GitHub:  @aduzsardi
### Keybase: @aduzsardi
### Requirements: bash, date, docker, jq

# Remove docker volumes last used more than a month ago

# https://www.gnu.org/software/coreutils/manual/html_node/Relative-items-in-date-strings.html
__older_than_unix_timestamp=$(date +%s --date="1 month ago")

for __volume in $(docker volume ls --format '{{.Name}}'); do  
        __volume_last_used_date=$(docker volume inspect "$__volume" | jq -r .[].CreatedAt) 
        __volume_unix_timestamp=$(date +%s --date=$__volume_last_used_date)
        if [[ $__volume_unix_timestamp -lt $__older_than_unix_timestamp ]]; then
            docker volume rm -f "$__volume"
        fi
done