function dump_postgres {
    mkdir -p ${BACKUP_DIR}/postgres/
    docker ps -a --format '{{.Names}}t{{.Ports}}' | grep 5432/tcp | awk '{ print $1 }' | while read -r line; do
        echo "extracting database from container '${line}'"
        docker exec -t ${line} pg_dumpall -v --lock-wait-timeout=600 -c -U postgres > ${BACKUP_DIR}/postgres/${line}.sql
    done
}

dump_postgres >> "${LOG}" 2>> "${ERROR}"