Re: Patch proposal: make use of regular expressions for the username in pg_hba.conf

On Fri, Sep 16, 2022 at 06:24:07PM +0200, Drouvot, Bertrand wrote:
> The CF bot is failing for Windows (all other tests are green) and only for
> the new tap test related to the regular expression on the host name (the
> ones on database and role are fine).
>
> The issue is not related to the patch. The issue is that the Windows Cirrus
> test does not like when a host name is provided for a "host" entry in
> pg_hba.conf (while it works fine when a CIDR is provided).
>
> You can see an example in [1] where the only change is to replace the CIDR
> by "localhost" in 002_scram.pl. As you can see the Cirrus tests are failing
> on Windows only (its log file is here [2]).
>
> I'll look at this "Windows" related issue but would appreciate any
> guidance/help if someone has experience in this area on windows.

I recall that being able to do a reverse lookup of a hostname on
Windows for localhost requires a few extra setup steps as that's not
guaranteed to be set in all environments by default, which is why we
go at great length to use 127.0.0.1 in the TAP test setup for example
(see Cluster.pm). Looking at your patch, the goal is to test the
mapping of regular expression for host names, user names and database
names. If the first case is not guaranteed, my guess is that it is
fine to skip this portion of the tests on Windows.

While reading the patch, I am a bit confused about token_regcomp() and
token_regexec(). It would help the review a lot if these were
documented with proper comments, even if these act roughly as wrappers
for pg_regexec() and pg_regcomp().
--
Michael