I am trying to provision PVC for Solr deployment in k8s and mount it as /opt/solr, which is default Solr installation directory. This way I plan to target both Solr installation and data under it on PVC. However, while storage gets provisioned just fine and statefulset gets created, my deployment doesn't work because /opt/solr ends up empty. What is a proper way to do it? Here my deployment.yaml:

apiVersion: apps/v1beta1
kind: StatefulSet
metadata:
  name: solr
  labels:
    app: solr

spec:
  volumeClaimTemplates:
  - metadata:
      name: datadir
      annotations:
        volume.alpha.kubernetes.io/storage-class: slow
    spec:
      accessModes: [ "ReadWriteOnce" ]
      resources:
        requests:
          storage: 2Gi

  serviceName: solr-svc
  replicas: 1
  template:
    metadata:
      labels:
        app: solr
    spec:
      affinity:
        podAntiAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            - labelSelector:
                matchExpressions:
                  - key: "app"
                    operator: In
                    values:
                    - solr-pool
              topologyKey: "kubernetes.io/hostname"
      terminationGracePeriodSeconds: 300
      containers: 
      - name: solr
        image: solr:6.5.1
        imagePullPolicy: IfNotPresent
        resources:
          requests:
            memory: 512M
            cpu: 500m
        ports:
        - containerPort: 8983
          name: solr-port
          protocol: TCP
        env:
        - name: VERBOSE
          value: "yes"
        command:
        - bash
        - -c
        - "exec /opt/solr/bin/solr start"
        volumeMounts:
        - name: solr-script
          mountPath: /docker-entrypoint-initdb.d/
        - name: datadir
          mountPath: /opt/solr/
      volumes:
        - name: solr-script
          configMap:
            name: solr-configs
      nodeSelector:
        pool: solr-pool