bash-3.2$ DATABASE_URL='postgres://username:password@hostname.net:port/dbname'
bash-3.2$ [[ $DATABASE_URL =~ (.*)'://'(.*):(.*)@(.*):(.*)/(.*) ]] && \
DB_USERNAME=${BASH_REMATCH[2]} \
DB_PASSWORD=${BASH_REMATCH[3]} \
DB_HOST=${BASH_REMATCH[4]} \
DB_PORT=${BASH_REMATCH[5]} \
DB_DBNAME=${BASH_REMATCH[6]} env |grep DB_
DB_PORT=port
DB_USERNAME=username
DB_DBNAME=dbname
DB_PASSWORD=password
DB_HOST=hostname.net