Running etherpad in readonly volume mode fails

apiVersion: v1
data:
  ADMIN_PASSWORD: nonEmpty
  DB_FILENAME: var/etherpad.sq3
  DB_TYPE: sqlite
  DEFAULT_PAD_TEXT: ' '
  DISABLE_IP_LOGGING: "true"
  NODE_ENV: production
  # changed port to > 1024 to prevent running with additional capabilities
  PORT: "9001"
  PRIVACY_PLUGIN_CATALOG: "false"
  PRIVACY_UPDATE_CHECK: "false"
  TRUST_PROXY: "true"
  UPDATES_TIER: "off"
kind: ConfigMap
metadata:
  annotations:
    meta.helm.sh/release-name: jitsi
    meta.helm.sh/release-namespace: jitsi
  creationTimestamp: "2026-07-23T21:38:41Z"
  labels:
    app.kubernetes.io/component: etherpad
    app.kubernetes.io/instance: jitsi
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/name: jitsi-meet
    app.kubernetes.io/version: stable-11031
    helm.sh/chart: jitsi-meet-2.22.2
    helm.toolkit.fluxcd.io/name: jitsi
    helm.toolkit.fluxcd.io/namespace: jitsi
  name: jitsi-jitsi-meet-etherpad
  namespace: jitsi
---
apiVersion: apps/v1
kind: Deployment
metadata:
  annotations:
    deployment.kubernetes.io/revision: "13"
    meta.helm.sh/release-name: jitsi
    meta.helm.sh/release-namespace: jitsi
  creationTimestamp: "2026-07-23T21:38:41Z"
  generation: 13
  labels:
    app.kubernetes.io/component: etherpad
    app.kubernetes.io/instance: jitsi
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/name: jitsi-meet
    app.kubernetes.io/version: stable-11031
    helm.sh/chart: jitsi-meet-2.22.2
    helm.toolkit.fluxcd.io/name: jitsi
    helm.toolkit.fluxcd.io/namespace: jitsi
  name: jitsi-jitsi-meet-etherpad
  namespace: jitsi
  resourceVersion: "11204879"
  uid: 01876c30-8453-433a-8978-6b65bfe1da9b
spec:
  progressDeadlineSeconds: 600
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      app.kubernetes.io/component: etherpad
      app.kubernetes.io/instance: jitsi
      app.kubernetes.io/name: jitsi-meet
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate
  template:
    metadata:
      annotations:
        checksum/config: 34dd7030c68a6f22361d17e07521f7431ec66d30524ab0725060fa8655283dcd
      labels:
        app.kubernetes.io/component: etherpad
        app.kubernetes.io/instance: jitsi
        app.kubernetes.io/name: jitsi-meet
    spec:
      automountServiceAccountToken: false
      containers:
      - envFrom:
        - configMapRef:
            name: jitsi-jitsi-meet-etherpad
        image: etherpad/etherpad:3.3.3
        imagePullPolicy: IfNotPresent
        livenessProbe:
          failureThreshold: 3
          httpGet:
            path: /
            port: 9001
            scheme: HTTP
          periodSeconds: 10
          successThreshold: 1
          timeoutSeconds: 1
        name: jitsi-meet
        ports:
        - containerPort: 9001
          name: http
          protocol: TCP
        readinessProbe:
          failureThreshold: 3
          httpGet:
            path: /
            port: 9001
            scheme: HTTP
          periodSeconds: 10
          successThreshold: 1
          timeoutSeconds: 1
        resources: {}
        securityContext:
          allowPrivilegeEscalation: false
          capabilities:
            drop:
            - ALL
          readOnlyRootFilesystem: true
          runAsNonRoot: true
          runAsUser: 5001
          seccompProfile:
            type: RuntimeDefault
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
        volumeMounts:
        - mountPath: /tmp
          name: tmp
        - mountPath: /opt/etherpad-lite/var
          name: data
        - mountPath: /opt/etherpad-lite/src/plugin_packages
          name: plugins
      dnsPolicy: ClusterFirst
      restartPolicy: Always
      schedulerName: default-scheduler
      securityContext: {}
      serviceAccount: jitsi-jitsi-meet
      serviceAccountName: jitsi-jitsi-meet
      terminationGracePeriodSeconds: 30
      volumes:
      - emptyDir: {}
        name: tmp
      - emptyDir: {}
        name: data
      - emptyDir: {}
        name: plugins