Feature: Set NC_serverid per instance

[pschichtel]

Description of the change

Since NC 33 the UI recommends setting NC_serverid to a unique value per server of a nextcloud cluster. Since the ids should be stable and unique it suggests using a StatefulSet and using its ordinal as the serverid value.

Docs: https://docs.nextcloud.com/server/33/admin_manual/configuration_server/config_sample_php_parameters.html#serverid

Benefits

Not sure what the actual benefit is, but since NC suggests/recommends it, I guess the chart should comply.

Possible drawbacks

No idea if setting NC_serverid has drawbacks, but switching to a StatefulSet does make things a little more complicated.

[csantv]

I managed to silence it for now with this snippet, I'm also not sure the benefits of having a "proper" value.

nextcloud:
  configs:
    serverid.config.php: |
      <?php
      $podName = getenv('K8S_POD_ID') ?: '0';
      $numericId = abs(crc32($podName)) % 1024;
      $CONFIG = array( 
        'serverid' => $numericId,
      );
  extraEnv:
    - name: K8S_POD_ID
      valueFrom:
        fieldRef:
          fieldPath: metadata.name

It won't change for as long as the pod lives. Setting NC_serverid is not appropriate I think as each pod is a nextcloud server with its own config.

[csantv]

Ignore my previous comment. This should be a proper config using init containers.

nextcloud:
  extraInitContainers:
    - name: generate-serverid-config
      image: busybox
      env:
        - name: POD_NAME
          valueFrom:
            fieldRef:
              fieldPath: metadata.name
      command: ["/bin/sh", "-c"]
      args:
        - |
          ID=$(echo $POD_NAME | cksum | awk '{print $1 % 1024}')
          echo "<?php \$CONFIG = array('serverid' => $ID);" > /var/local/serverid.config.php
      volumeMounts:
        - name: nextcloud-serverid-config
          mountPath: "/var/local/"

  extraVolumes:
  - name: nextcloud-serverid-config
    emptyDir: {}

  extraVolumeMounts:
  - name: nextcloud-serverid-config
    mountPath: "/var/www/html/config/serverid.config.php"
    subPath: serverid.config.php

[pschichtel]

I wonder if it'd a problem, that this will produce new ids on every restart

[csantv]

That makes sense I think as pods are new nextcloud servers. You could also checksum the node name instead and have more stable values.