postgres-operator VS democratic-csi

As for the Operators, I've been using Crunchy PGO, which is very high quality, and one of the most widely used. You can install it via Helm, or via OLM from OperatorHub. There are other good ones as well, but none that I have experience with. The only issue I've run into so far is I've had to disable TLS on the database cluster, as Prowlarr refused to connect with it for some reason (Radarr was fine). I still need to open an issue with the Prowlarr team about that, but I might switch to a service mesh for TLS anyway.

The Crunchy operator, seemingly like most (if not all) of the other Postgres operators (Zalando, KubeDB, and StackGres, etc.), is essentially a wrapper for Patroni. IMO if someone wanted a Patroni cluster, they would just build one. The point of an operator is to manage the cluster resources and node relationships, so why not have it take the role Patroni is filling here? It's already reaching into the nodes, obtaining status, managing the routing, etc., so why add the extra layer?

On the topic of Postgres, you should look into an operator or Helm chart that can setup common things (like replication and auto-failover), such as Crunchy's Postgres operator, or consider using a "cloud-native" distributed database like CockroachDB (disclaimer: I am a Cockroach Labs employee) which has its own operator as well. Another word of warning, running stateful services, particularly mission critical databases, can require a lot of maintenance work (it's my full-time job), so unless this is for a hobby project, I would highly recommend you look into using a managed database offerring. Every major cloud provider and most database companies have one.

For postgres you can also have a look at PGO or bitnami helm chart

Let's say a new Kubernetes version comes out in April. In November, as everything works perfectly well, you decide to install a Postgres operator on it. Bummer, it doesn't work. It's not a huge issue, you just wait until the bug is resolved (already done[0]), but it's just one of these tiny things that I don't get when running Postrges natively. And I'm saying this as a big fan of Crunchy Data running some production loads on it without a failure for quite some time now.

[0] https://github.com/CrunchyData/postgres-operator/issues/3476

There is one particular client that have a somewhat big database 40-120gb (it change size over the year), and for that we used CrunchyData Postgres operator ( https://access.crunchydata.com/documentation/postgres-operator/v5/ ) we have no commercial relation with them, but oboi let me tell you the god send that thing is, this database in specific process massive data and it is distributed between several nodes in a read-write and read-only set, and let me tell you, it is amazing how easy it is to move things around, take backups, increase the capacity and a bunch of other goodies that operator bring. Give it a try.

The interface software regarding is not a worry of mine, as democratic-csi does the storage management for me, thus the compatibility it is not limited to the application using the storage per se, as this is handled by Kubernete's CSI drivers, being application-agnostic when utilizing the storage provided.My main worry is not latency, but rather RAM

Check out https://github.com/democratic-csi/democratic-csi

in k3s, i'm using https://github.com/democratic-csi/democratic-csi (was using iSCSI before, now everything is NFS)

Have you checked this out? GitHub democratic-csi I have yet to test this in my @home K8s cluster. It supports iSCSI volume management for FreeNAS, Synology and other CSI backends.

If you ever migrate from docker up to kubernetes, then take a look into democratic-csi. For a modest homelab, it is a valid option (said from somebody who manages a small homelab and plays around with kubernetes).

For persistent storage have you looked into using TrueNAS with a CSI provider with your container orchestrator? I'm assuming your orchestrator is Nomad or Kubernetes.

Yes, Rancher does support FreeNAS, TrueNAS. and Scale using the storage class provider https://github.com/democratic-csi/democratic-csi It's important to remember Rancher is the server. And in this case, you need to ask the question does the k8s cluster that Rancher is managing support this storage class provider? If you are using RKE the answer is Yes.

I use https://github.com/democratic-csi/democratic-csi to mount nfs/iscsi shares (and manage the shares) from my SAN (truenas box).

iSCSI with democratic-csi (https://github.com/democratic-csi/democratic-csi) works great for me on truenas. I use iSCSI for any PVs that don't need to be shared and NFS for anything I'd like to share between different pods (like movies, music).

Storage - democratic-csi looked the most promising, it has worked well so far. I am using zfs-generic-iscsi against an Ubuntu 20.04 storage server. I also tried zfs-generic-nfs and it worked successfully with the caveat of having to deal with NFS file permissions.