How to configure mdadm.conf?

[thoro]

Hello,

I do not want mdadm to auto assemble arrays for me, how can I add:

AUTO -all

to the mdadm.conf file?

[frezbo]

this is not possible at the moment, but this can be made configurable via ExtensionServiceConfig

[thoro]

Do you have an example how this could be integrated into an extension? I maybe would be willing to create a PR for the mdadm extension then.

[frezbo]

you can take a look at nut-client extension, the mdadm extension probably needs a flag to point to a config file

[thoro]

mdadm implicitly reads the config file, because it's called via udevd (rules defined in the extension)

the usual place is /etc/mdadm.conf, can you also set it at this location via the ExtensionServiceConfig?

[frezbo]

mdadm implicitly reads the config file, because it's called via udevd (rules defined in the extension)

the usual place is /etc/mdadm.conf, can you also set it at this location via the ExtensionServiceConfig?

we might have to compile mdadm to use a custom path then, extensions only allow /usr/local

[thoro]

I tried to just apply an ExtensionServiceConfig now, but talosctl ls /usr/local/etc/mdadm.conf reports non-existing.

apiVersion: v1alpha1
kind: ExtensionServiceConfig
name: mdadm
configFiles:
  - content: |-
        AUTO -all
    mountPath: /usr/local/etc/mdadm.conf

When are those configs applied? Do you need to run a container in the extension? Are the names supposed to be the same as the extension?

[frezbo]

I tried to just apply an ExtensionServiceConfig now, but talosctl ls /usr/local/etc/mdadm.conf reports non-existing.

apiVersion: v1alpha1
kind: ExtensionServiceConfig
name: mdadm
configFiles:
  - content: |-
        AUTO -all
    mountPath: /usr/local/etc/mdadm.conf

When are those configs applied? Do you need to run a container in the extension? Are the names supposed to be the same as the extension?

yes, it only gets in effect when there is an extension with the same name

[thoro]

I checked the executable, and looks like the path is sadly not compiled in correctly.

 salt/talos  (k8s: admin@dc-at-prod-02) $ talosctl --talosconfig=.talosconfig  -n dc-at-prod-02-h01 get extensions 2
NODE                NAMESPACE   TYPE              ID   VERSION   NAME    VERSION
dc-at-prod-02-h01   runtime     ExtensionStatus   2    1         mdadm   v4.2
 salt/talos  (k8s: admin@dc-at-prod-02) $ talosctl --talosconfig=.talosconfig  -n dc-at-prod-02-h01 get extensionserviceconfig mdadm
NODE                NAMESPACE   TYPE                     ID      VERSION
dc-at-prod-02-h01   runtime     ExtensionServiceConfig   mdadm   1
 salt/talos  (k8s: admin@dc-at-prod-02) $ talosctl --talosconfig=.talosconfig  -n dc-at-prod-02-h01 get extensionserviceconfig mdadm -o yaml;
node: dc-at-prod-02-h01
metadata:
    namespace: runtime
    type: ExtensionServiceConfigs.runtime.talos.dev
    id: mdadm
    version: 1
    owner: runtime.ExtensionServiceConfigController
    phase: running
    created: 2024-07-18T12:05:45Z
    updated: 2024-07-18T12:05:45Z
spec:
    files:
        - content: AUTO -all
          mountPath: /usr/local/etc/mdadm.conf
 salt/talos  (k8s: admin@dc-at-prod-02) $ talosctl --talosconfig=.talosconfig  -n dc-at-prod-02-h01 ls /usr/local/etc/mdadm.conf
NODE   NAME
1 error occurred:
 rpc error: code = Unknown desc = lstat /usr/local/etc/mdadm.conf: no such file or directory

I have readded the mdadm extension to my cluster, but the ExtensionServiceConfig is still not applied as expected - ideas?

[thoro]

@frezbo Can you check this one here: https://github.com/siderolabs/extensions/pull/430 ?

[frezbo]

ahh ExtensionServiceConfig is currently only for extension services, not plain extensions

Also can we specify the config file here: https://github.com/siderolabs/extensions/blob/main/storage/mdadm/files/udev-md-raid-arrays.rules#L20?

[thoro]

~sadly not, it's hardcoded in the source via define, there's no option to pass config file via cli args~

Edit: Sorry, I was wrong .. seems to be a -c option!

[thoro]

~is there a build services to get a test image out of the PR - I can't build it on my M2 mac~ Edit: solved it, I added by mistake a space into the pkg.yaml, that removed an important build env var.

[thoro]

@frezbo I added the the -c option to specify the config file in the udev rules. What I do not understand yet, is how to get a config file into that folder anyways 😃

Edit: I think the config file is rather well stored under /var/lib/mdadm/mdadm.conf but please let me know what's the correct destination, and how to actually edit that file then.

[frezbo]

@frezbo I added the the -c option to specify the config file in the udev rules. What I do not understand yet, is how to get a config file into that folder anyways 😃

Edit: I think the config file is rather well stored under /var/lib/mdadm/mdadm.conf but please let me know what's the correct destination, and how to actually edit that file then.

we don't have a good way in talos now to get a config file or have a default one so that the it doesn't break existing config, let's keep a hold on to this until we have a better solution from talos/extensions side