postgres.nix

{ pgdata, dbport ? "5432" }:
let
    pkgs = import <nixpkgs> {};
in
pkgs.mkShell {
    packages = with pkgs; [ postgresql cowsay ];
    shellHook = ''
      export PGDATA=${pgdata}
      fg_postgres() {
        trap "pg_ctl -D $PGDATA stop && cowsay server stopped on $PGDATA:${dbport}" EXIT

        if ! test -d $PGDATA
        then
          pg_ctl initdb -D $PGDATA
          sed -i "s|^#port.*$|port = ${dbport}|" $PGDATA/postgresql.conf
        fi

        # These are only suitable for development.
        HOST_COMMON="host\s\+all\s\+all"
        sed -i "s|^$HOST_COMMON.*127.*$|host all all 0.0.0.0/0 trust|" $PGDATA/pg_hba.conf
        sed -i "s|^$HOST_COMMON.*::1.*$|host all all ::/0 trust|"      $PGDATA/pg_hba.conf

        pg_ctl                                                  \
          -D $PGDATA                                            \
          -l $PGDATA/postgres.log                               \
          -o "-c unix_socket_directories='$PGDATA'"             \
          -o "-c listen_addresses='*'"                          \
          -o "-c log_destination='stderr'"                      \
          -o "-c logging_collector=on"                          \
          -o "-c log_directory='log'"                           \
          -o "-c log_filename='postgresql-%Y-%m-%d_%H%M%S.log'" \
          -o "-c log_min_messages=info"                         \
          -o "-c log_min_error_statement=info"                  \
          -o "-c log_connections=on"                            \
          start

        tail -F $PGDATA/postgres.log
      }
    '';
}