用配置文件初始化Kubernetes PersistentVolume

Question

我已经配置了一个Kubernetes集群来创建带有三个Pod的StatefulSet。每个Pod都有自己的PersistentVolumeClaim。运行此配置可以正常工作，并启动Pod。现在，我想用Gradle的配置文件填充每个PersistentVolume。这就是我的Kubernetes配置的样子（无关的部分被省略/混淆）：

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: my-statefulset
spec:
  selector:
    matchLabels:
      app: my-statefulset
  serviceName: "my-statefulset"
  replicas: 3
  template:
    metadata:
      labels:
        app: my-statefulset
    spec:
      containers:
        - name:  my-statefulset
          image: path.to.some.artifactory.com/some-image:1.2.3
          volumeMounts:
            - name: my-volume
              mountPath: /home/foo/.gradle
              subPath: gradle
      initContainers:
        - name: my-statefulset-init
          image: path.to.some.artifactory.com/some-image:1.2.3
          volumeMounts:
            - mountPath: /home/foo/.gradle
              name: my-volume
              subPath: gradle
          command:
            - sh
            - '-c'
            - 'cp'
            - "./gradle.properties"
            - "/home/jenkins/.gradle/gradle.properties"
  volumeClaimTemplates:
    - metadata:
        name: my-volume
      spec:
        accessModes: [ "ReadWriteOnce" ]
        resources:
          requests:
            storage: 150Gi

YAML与配置中引用的./gradle.properties一起位于目录中。从该文件夹中依次使用kubectl appy -f .和kubectl get pods -o wide运行配置时，我得到以下输出：

my-statefulset-0                 0/1     Init:CrashLoopBackOff   7          12m     11.32.13.2    aee05ea1-809c-4b35-8533-131e818eb1cc   <none>

调用kubectl describe pod my-statefulset-0会产生：

Events:
  Type     Reason                  Age               From                                           Message
  ----     ------                  ----              ----                                           -------
  Normal   Scheduled               27s               default-scheduler                              Successfully assigned somuser/my-statefulset-0 to 8599877f-090d-4e6e-b556-d60f5c3d4334
  Normal   SuccessfulAttachVolume  25s               attachdetach-controller                        AttachVolume.Attach succeeded for volume "pvc-b2354b68-aa0d-11e9-90f5-005056863826"
  Normal   Pulled                  8s (x2 over 10s)  kubelet, 8599877f-090d-4e6e-b556-d60f5c3d4334  Container image "path.to.some.artifactory.com/some-image:1.2.3" already present on machine
  Normal   Created                 8s (x2 over 9s)   kubelet, 8599877f-090d-4e6e-b556-d60f5c3d4334  Created container
  Normal   Started                 8s (x2 over 9s)   kubelet, 8599877f-090d-4e6e-b556-d60f5c3d4334  Started container
  Warning  BackOff                 6s (x2 over 7s)   kubelet, 8599877f-090d-4e6e-b556-d60f5c3d4334  Back-off restarting failed container

我知道该命令显然是从容器/容器内部运行的，无法访问本地计算机上的./gradle.properties文件。但是，如何在特定位置轻松地用配置文件填充PersistentVolume？ Kubernetes Documentation about InitCountainers明确提到配置文件是一个用例，但没有给出我想要实现的示例。

请注意，由于公司的限制，我不能为InitContainer使用busybox。但是，在Pod中运行的映像包含完整的Linux发行版。这就是为什么我也将它用于InitContainer。