Re: Repeatable builds using pkgbase

On Mon, Aug 21, 2023 at 02:33:24PM +0100, Doug Rabson wrote:
> While working on build scripts for FreeBSD container images, I wanted to
> get to the point where my builds are repeatable, i.e. if I create two
> images with the same set of packages installed in the same order, they
> should be identical.
> 
> The main stumbling block is timestamps. I can force all the file timestamps
> to a fixed value with buildah using the '--timestamp' argument to either
> 'buildah commit' or 'buildah build' but even then, the two images have
> different hashes. Looking deeper, the difference is in
> /var/db/pkg/local.sqlite. If I compare SQL dumps of the databases from each
> image, I can see a timestamp embedded in the sqlite file:
> 
> diff dump1 dump2
> 
> 
> 4c4
> < INSERT INTO packages
> VALUES(1,'base','FreeBSD-zoneinfo','13.2p2','zoneinfo package','zoneinfo
> package',NULL,NULL,'FreeBSD:13:amd64','re@FreeBSD.org','
> https://www.FreeBSD.org
> ','/',731014,0,0,1,1692446701,'2$2$c9w95oqai9bwhny1k4pcg8mji77xgk43zjxxb69j1duzq5jao18wak4deer85epmfpc8ngyysyt9wu74pg7sczkqc3ekyawkfgwzi8d',NULL,NULL,0);
> ---
> > INSERT INTO packages
> VALUES(1,'base','FreeBSD-zoneinfo','13.2p2','zoneinfo package','zoneinfo
> package',NULL,NULL,'FreeBSD:13:amd64','re@FreeBSD.org','
> https://www.FreeBSD.org
> ','/',731014,0,0,1,1692622924,'2$2$c9w95oqai9bwhny1k4pcg8mji77xgk43zjxxb69j1duzq5jao18wak4deer85epmfpc8ngyysyt9wu74pg7sczkqc3ekyawkfgwzi8d',NULL,NULL,0);
> 
> 
> Looking at the pkg source, I can see that the prepared statement for
> inserting into the packages table explicitly uses NOW() for this column.
> Would it be reasonable to allow changing this, e.g. by adding a command
> line argument to pkg to override the default? I haven't tried this to see
> if that makes the two databases identical - if not, I guess I'll just
> remove pkg metadata altogether.

yes this would be reasonable, if you use en env var, please respect
SOURCE_DATE_EPOCH.

Best regards,
Bapt