Switch to cloudpirates redis / memcached chart and image

[mgruner]

Which issue this PR fixes

• fixes redis cve-2025-49844 Critical CVSS 10. #367

Checklist

• Chart Version bumped
• Upgrading instructions are documented in the zammad/README.md

[mgruner]

@monotek I'm not entirely sure if this would be a good path, but the cloudpirates/redis helm chart seems to be modeled after the bitnami chart. Data migration should not be needed. We could also consider switching memcached as well. Would this require a major update?

[monotek]

I guess i would raise the major version number of the chart and add it as info to the upgrading section, so people are aware, even if no upgrade steps are required.

[mgruner]

https://artifacthub.io/packages/helm/cloudnative-pg/cloudnative-pg looks like a good option for postgres.

[github-actions]

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[monotek]

cloudnative-pg

I've tried cnpg a while ago and the cluster was broken from time to time.
So currently i still use the zalando postgres operator.

For zammad chart usecase (single pod / no cluster) it might be ok though.
I also would give cnpg a new chance as there is now also active active support via pgEdge.

If we use operators now we could also switch to the eck operator for elasticsearch.

[mgruner]

@monotek my idea would be that for Zammad 7.0 (early March) we only switch redis, memcached and perhaps also Elasticsearch. I would not touch postgresql just yet, this could come with another major update later. Data migration might be challenging here.

For elasticsearch, there is a chart from the vendor on artifact hub. We should probably go with this unless there are strong reasons against?

[mgruner]

We could consider a PG switch now if there's an easy migration path.

[monotek]

We could consider a PG switch now if there's an easy migration path.

I don't think you'll find an easy one.
For PG it likely will be creating a new instance and you have to import a backup.

For Elasticsaerch with eck operator it's nearly the same.
New instance and resync.