Moreno Andreo <moreno.andreo@evolu-s.it> writes:
> Hi folks,
> I'm trying to install Postgresql 9.6 on a test machine in Google Cloud
> Platform
> After a fresh install with Debian 9 (just after the instance has been
> created) I follow steps from here
>
> https://wiki.postgresql.org/wiki/Apt
>
> (instead of pg 10 I install pg 9.6)
>
> During the installation process i encounter the following strange
> warnings that, even if that's a test machine, make me think twice before
> going ahead.
>
> [...]
> Processing triggers for man-db (2.7.6.1-2) ...
> Setting up pgdg-keyring (2017.3) ...
> Removing apt.postgresql.org key from trusted.gpg: Warning: The postinst
> maintainerscript of the package pgdg-keyring
> Warning: seems to use apt-key (provided by apt) without depending on
> gnupg or gnupg2.
> Warning: This will BREAK in the future and should be fixed by the
> package maintainer(s).
> Note: Check first if apt-key functionality is needed at all - it
> probably isn't!
> OK
> Setting up xml-core (0.17) ...
> [...]
>
> I have to say that installation is successfully and database server goes
> up and apparently with no problems at all.
>
This looks like a warning for the package maintainers regarding ensuring
the package depends on either gnupg or gnupg2 and nothing you need to
worry about unless you are building/maintaining deb packages for postgres.
The Debian package manager, apt, uses gpg keys to verify the
authenticity of packages it downloads. My guess is that previously, you
only needed to ensure the package had a dependency on apt-key and now
apt has/is changing such that you need to have an explicit dependency on
either gnupg or gnupg2.
--
Tim Cross