nixpkgs/nixos/tests/postgresql/anonymizer.nix

{
  pkgs,
  makeTest,
  genTests,
}:

let
  inherit (pkgs) lib;

  makeTestFor =
    package:
    makeTest {
      name = "postgresql_anonymizer-${package.name}";
      meta.maintainers = lib.teams.flyingcircus.members;

      nodes.machine =
        { pkgs, ... }:
        {
          environment.systemPackages = [ pkgs.pg-dump-anon ];
          services.postgresql = {
            inherit package;
            enable = true;
            extensions = ps: [ ps.anonymizer ];
            settings.shared_preload_libraries = [ "anon" ];
          };
        };

      testScript = ''
        start_all()
        machine.wait_for_unit("multi-user.target")
        machine.wait_for_unit("postgresql.target")

        with subtest("Setup"):
            machine.succeed("sudo -u postgres psql --command 'create database demo'")
            machine.succeed(
                "sudo -u postgres psql -d demo -f ${pkgs.writeText "init.sql" ''
                  create extension anon cascade;
                  select anon.init();
                  create table player(id serial, name text, points int);
                  insert into player(id,name,points) values (1,'Foo', 23);
                  insert into player(id,name,points) values (2,'Bar',42);
                  security label for anon on column player.name is 'MASKED WITH FUNCTION anon.fake_last_name();';
                  security label for anon on column player.points is 'MASKED WITH VALUE NULL';
                ''}"
            )

        def get_player_table_contents():
            return [
                x.split(',') for x in machine.succeed("sudo -u postgres psql -d demo --csv --command 'select * from player'").splitlines()[1:]
            ]

        def check_anonymized_row(row, id, original_name):
            assert row[0] == id, f"Expected first row to have ID {id}, but got {row[0]}"
            assert row[1] != original_name, f"Expected first row to have a name other than {original_name}"
            assert not bool(row[2]), "Expected points to be NULL in first row"

        def find_xsv_in_dump(dump, sep=','):
            """
            Expecting to find a CSV (for pg_dump_anon) or TSV (for pg_dump) structure, looking like

                COPY public.player ...
                1,Shields,
                2,Salazar,
                \.

            in the given dump (the commas are tabs in case of pg_dump).
                  Extract the CSV lines and split by `sep`.
            """

            try:
                from itertools import dropwhile, takewhile
                return [x.split(sep) for x in list(takewhile(
                    lambda x: x != "\\.",
                    dropwhile(
                        lambda x: not x.startswith("COPY public.player"),
                        dump.splitlines()
                    )
                ))[1:]]
            except:
                print(f"Dump to process: {dump}")
                raise

        def check_original_data(output):
            assert output[0] == ['1','Foo','23'], f"Expected first row from player table to be 1,Foo,23; got {output[0]}"
            assert output[1] == ['2','Bar','42'], f"Expected first row from player table to be 2,Bar,42; got {output[1]}"

        def check_anonymized_rows(output):
            check_anonymized_row(output[0], '1', 'Foo')
            check_anonymized_row(output[1], '2', 'Bar')

        with subtest("Check initial state"):
            check_original_data(get_player_table_contents())

        with subtest("Anonymous dumps"):
            check_original_data(find_xsv_in_dump(
                machine.succeed("sudo -u postgres pg_dump demo"),
                sep='\t'
            ))
            check_anonymized_rows(find_xsv_in_dump(
                machine.succeed("sudo -u postgres pg_dump_anon -U postgres -h /run/postgresql -d demo"),
                sep=','
            ))

        with subtest("Anonymize"):
            machine.succeed("sudo -u postgres psql -d demo --command 'select anon.anonymize_database();'")
            check_anonymized_rows(get_player_table_contents())
      '';
    };
in
genTests {
  inherit makeTestFor;
  filter = _: p: !p.pkgs.anonymizer.meta.broken;
}