So do people containerize databases in production these days? I thought a couple of years ago DBs were the classic example of applications that don't belong in containers.
Depends on the scale. Something small is okay to keep in containers. If you want to push performance to the limits - you definitely will run your DBMS outside a container.
Services should be decoupled from OS distro dependencies as much as possible, otherwise you will be bitten at an unexpected moment (e.g. upgrading your distro packages) by some problem like this https://wiki.postgresql.org/wiki/Locale_data_changes
This can be solved by building statically (or using something like Nix) or by at least using containers.
I do, but I take a very cautious approach. I run a custom image with PostgreSQL and Patroni on Kubernetes, no operator, each replica has it's own StatefulSet tied to a specific node. There is very little automation, but it still better than running PostgreSQL outside of Kubernetes. I get the benefit of simplified monitoring, log handling, request routing, while still having very static resource assignments.
To host it in an orchestrator your cluster has to be more available than your DB.
you want 3 9s of availability for your DBs maybe more.
Then you need 4 9s for your cluster/orchestrator.
If your team can make that cluster, then it makes more sense to put all under one roof then develop a whole new infrastructure with the same level of reliability or more.
This is a persistent myth that is just flat out wrong. Your k8s cluster orchestrator does not need to be online very often at all. The kube proxies will gladly continue proxying traffic as last they best know. Your containers will still continue to run. Hiccups, or outright outages, in the kubi API server do not cause downtime, unless you are using certain terrible, awful, no good, very bad proxies within the cluster (istio, linkerd).
I also would like to know this, I was just told that databases should be outside the cluster a couple days ago by someone with a decade of K8s experience.
Well, CloudnativePG exists and it works really really well. At some point if you can afford to have someone manage your databases separately from your applications, you can think about putting it outside the cluster but I'd wager at some point you've got enough experience with running your DB with an operator that you can keep running it in the cluster.
Readit News
This can be solved by building statically (or using something like Nix) or by at least using containers.
you want 3 9s of availability for your DBs maybe more.
Then you need 4 9s for your cluster/orchestrator.
If your team can make that cluster, then it makes more sense to put all under one roof then develop a whole new infrastructure with the same level of reliability or more.
Unless you have a dedicated team to do the stuff for you.
Crunchydata is a good starting point
Fuck them