nixosTests.matomo: extend test coverage

        machine.wait_for_unit("phpfpm-matomo.service")

        machine.wait_for_unit("nginx.service")

        with subtest("matomo.js reachable via HTTP"):

          machine.succeed("curl -sSfk http://machine/matomo.js")

        with subtest("js/piwik.js reachable via HTTP"):

          machine.succeed("curl -sSfk http://machine/js/piwik.js")

        with subtest("matomo.php (API) reachable via HTTP"):

          machine.succeed("curl -sSfk http://machine/matomo.php")

        # without the grep the command does not produce valid utf-8 for some reason

        with subtest("welcome screen loads"):

            machine.succeed(

                "curl -sSfL http://localhost/ | grep '<title>Matomo[^<]*Installation'"

            )

        with subtest("killing the phpfpm process should trigger an automatic restart"):

          machine.succeed("systemctl kill -s KILL phpfpm-matomo")

          machine.sleep(1)

          machine.wait_for_unit("phpfpm-matomo.service")

      '';

    };

in