shellHook = ''
    export PGDATA=$PWD/postgres_data
    export PGHOST=$PWD/postgres
    export LOG_PATH=$PWD/postgres/LOG
    export PGDATABASE=postgres
    export DATABASE_URL="postgresql:///postgres?host=$PGHOST"
    if [ ! -d $PGHOST ]; then
      mkdir -p $PGHOST
    fi
    if [ ! -d $PGDATA ]; then
      echo 'Initializing postgresql database...'
      initdb $PGDATA --auth=trust >/dev/null
    fi
    pg_ctl start -l $LOG_PATH -o "-c listen_addresses= -c unix_socket_directories=$PGHOST"
  '';