Upgrade zulip-postgresql container image based on postgres 14

[varac]

The PostgreSQL database details say:

We recommend that installations currently using older PostgreSQL releases upgrade to PostgreSQL 14, as we may drop support for older PostgreSQL in a future release.

But the current zulip-postgresql container image is still based on postgres 10.
Please provide a version based on postgres 14.

[alya]

@alexmv You are probably aware of this, but tagging you just in case.

[zulipbot]

Hello @zulip/server-production members, this issue was labeled with the "area: production" label, so you may want to check it out!

[alexmv]

I wasn't aware of it -- thanks for calling it out.

We don't have any build steps written down for how the zulip-postgresql container image was generated. My belief is that it's just adding the tsearchextras extension, which we can do with a very minor layer atop the official image.

I think the more complicated question, which I don't have an answer to off the top of my head, is how we manage the database upgrade path. We can't just drop in a new version of the postgresql container, since the data files would still be for postgresql 10.

We may need something like https://github.com/tianon/docker-postgres-upgrade to upgrade the data, and we'll need to document some manual steps to do so.

[andersk]

The zulip-postgresql container is built from Dockerfile-postgresql. The build instructions there are a bit of a lie: a mere docker build doesn’t suffice anymore because it’s a multi-architecture amd64+arm64 image now.

docker-zulip does at least use the zulip/zulip-postgresql:10 tag, so we could push a :14 tag without interfering with it. That doesn’t in itself solve the upgrade problem though, as you noted.

[alexmv]

Ugh, why is the postgresql container the one Dockerfile in zulip/zulip?