Add cnpg 18.0 to versions matrix

[Jimver]

The 'regular' 18-0.5.3 image is already released at https://github.com/tensorchord/VectorChord/pkgs/container/vchord-postgres/527350537?tag=pg18-v0.5.3

Let's do the same for the cnpg version

[bo0tzz]

@xieydd do we care to include pg 18+ here at all, or should we steer people towards using the ImageVolume mounts for extensions instead?

[Jimver]

Hmm yeah CI is also failing, I see now that the cnpg images seem to publish 18 only with the system/minimal image types specified in the tag, like 18.0-system-bookworm, but not 18.0-bookworm. See for example https://github.com/cloudnative-pg/postgres-containers/pkgs/container/postgresql/549857877?tag=18.0-system-bookworm

[Jimver]

@xieydd do we care to include pg 18+ here at all, or should we steer people towards using the ImageVolume mounts for extensions instead?

@bo0tzz Any example for this I can refer to? Couldn't find any from a cursory kubesearch

[bo0tzz]

https://docs.vectorchord.ai/vectorchord/admin/kubernetes.html#lightweight-extension-images

[xieydd]

@xieydd do we care to include pg 18+ here at all, or should we steer people towards using the ImageVolume mounts for extensions instead?

Currently, it seems that ImageVolume has some requirements for container runtime, Kubernetes version, and CNPG version, and the user's environment may not meet them. I think if there is a need, we can support it. Is ImageVolume suitable for your scenario? @Jimver

[Jimver]

Lmk if we should take this somewhere else but the linked example doesn't work for me, getting the following error in the initdb pod:

{"level":"info","ts":"2025-11-01T15:26:40.823893072Z","logger":"pg_ctl","msg":"waiting for server to start....2025-11-01 15:26:40.823 UTC [35] FATAL:  could not access file \"vchord\": No
 such file or directory","pipe":"stdout","logging_pod":"vchord-1-initdb"}

I have enabled the ImageVolume feature gate and am running on k8s v1.34.1
cnpg chart version 0.26.1, just copied the yaml straight from the example.

apiVersion: v1
kind: Secret
metadata:
  name: tensorchord
type: kubernetes.io/basic-auth
data:
  password: dGVuc29yY2hvcmQ= # tensorchord 
  username: dGVuc29yY2hvcmQ= # tensorchord
---
apiVersion: postgresql.cnpg.io/v1
kind: Cluster
metadata:
  name: vchord 
spec:
  instances: 1 
  imageName: ghcr.io/cloudnative-pg/postgresql:18-system-bookworm
  bootstrap:
    initdb:
      database: tensorchord
      postInitApplicationSQL:
        - CREATE EXTENSION IF NOT EXISTS vchord CASCADE;
      owner: tensorchord
      secret:
        name: tensorchord
      dataChecksums: true
      encoding: 'UTF8'
  storage:
    size: 1Gi
  postgresql:
    extensions:
      - name: vchord
        image:
          reference: ghcr.io/tensorchord/vchord-scratch:pg18-v0.5.3
        dynamic_library_path:
          - /usr/lib/postgresql/18/lib/
        extension_control_path:
          - /usr/share/postgresql/18/
    shared_preload_libraries:
    - "vchord"

[Jimver]

I have enabled the ImageVolume feature gate

I only did this on the kubelet, not the apiServer. After doing that as well it worked.

[xieydd]

Will add 18 after #67 .