CoreDNS configmap (coredns, in kube-system namespace) overwrite

[kalos]

Hi. I noticed that with each patch/update the Corefile configmap is overwritten.

Is there any way to avoid this or to include other configmaps?

AKS and DigitalOcean adopts an interesting solution: https://docs.digitalocean.com/products/kubernetes/how-to/customize-coredns/

Is there a similar function on ovh?

Is it possible to expect a change to the default Corefile similar to the one in the DO site?

[mhurtrel]

Hello @kalos ans sorry for the delay, was off for a few weeks and needed to discuss than with the team. I confirm I see the use case and enter this is our mid term backlog.

[JulienCharge]

Hello @mhurtrel We encounter the same problem, we would like to overload the config corefile. Do you have visibility on the implementation of this development.

We need it to add a zone and a forward to our DNS servers located on the SDDC.

Thank you for your reply,

[mhurtrel]

Hello @JulienCharge I confirm this will be supported but I can't yet share an ETA. Will try to get one and update this task, sorry for the delay.

[Grounz]

Hello @mhurtrel have you a news on this topic ?

[mhurtrel]

Hello @Grounz I confirm we plan to have this one tackled before the end of the summer. i will update with a more precise ETA in a couple of week.

[mhurtrel]

This issue will be tackled late summer

[jMonsinjon]

Hello, We are designing this feature and several implementations seem possible. One of the possibilities is to use the native import mechanism of CoreDNS (just like AKS or DigitalOcean) https://coredns.io/plugins/import/

Are you OK with this type of implementation? Do you have any comments? Special wishes for overload file naming?

[kalos]

I suggest to use DigitalOcean convention "custom/*.override" for default server block and "custom/*.server" for additional server block. Name of configmap: coredns-custom.

Thanks

[d--j]

I suggest to use DigitalOcean convention "custom/*.override" for default server block and "custom/*.server" for additional server block. Name of configmap: coredns-custom.

looks like that is the same as what AKS does. I think OVH should stick with that naming scheme, too.

[lenglet-k]

Hi @mhurtrel have you any news ?

[mhurtrel]

Hello @lenglet-k Our Current ETA is October, hopefully early in the month.

[jMonsinjon]

We are doing our best to deploy this feature end of September or early October (available through API)

[jMonsinjon]

Hello, This feature has been released but the documentation is still in progress.

On every new K8S cluster, or after an update, the new CoreDNS config will include an expansion mechanism. You can see now a new configmap named 'coredns-custom' that can be modified to add your specific configuration. The original coredns config must still not be changed because we can reset it at any time.

For example

$ kubectl -n kube-system edit cm coredns-custom
...
data:
  example.server: |
    my-custom-domain.local.:53 {
    forward . [my-custom-dns-server-private-ip]
  }

[scraly]

Hi, A new tutorial about how to customize CoreDNS have been released: https://docs.ovh.com/gb/en/kubernetes/customizing-coredns/ 🙂