將 Kubernetes Postgres pod 連接到存儲在持久卷上的現有數據庫

Question

我正在嘗試將在 Kubernetes 中運行的新 Wiki.js 應用程序實例連接到從先前應用程序實例創建並存儲在持久卷中的 Postgres 數據庫。 我得到一個CrashLoopBackOff嘗試啟動 postgres pod，查看它們顯示的日志：

The files belonging to this database system will be owned by user "postgres".
This user must also own the server process.

The database cluster will be initialized with locale "en_US.utf8".
The default database encoding has accordingly been set to "UTF8".
The default text search configuration will be set to "english".

Data page checksums are disabled.

initdb: directory "/var/lib/postgresql/data" exists but is not empty
If you want to create a new database system, either remove or empty
the directory "/var/lib/postgresql/data" or run initdb
with an argument other than "/var/lib/postgresql/data".

如您所見，它嘗試調用initdb失敗，因為已經存在數據...我的主要問題是如何配置以使用現有數據而不是嘗試創建新數據庫？？？

我的 kubernetes postgres 部署配置：

Name:                   postgres
Namespace:              wiki
CreationTimestamp:      Fri, 23 Aug 2019 22:17:44 +0000
Labels:                 app=postgres
Annotations:            deployment.kubernetes.io/revision: 36
Selector:               app=postgres
Replicas:               1 desired | 1 updated | 1 total | 0 available | 1 unavailable
StrategyType:           RollingUpdate
MinReadySeconds:        0
RollingUpdateStrategy:  1 max unavailable, 1 max surge
Pod Template:
  Labels:  app=postgres
  Containers:
   postgres:
    Image:      postgres:11.5
    Port:       5432/TCP
    Host Port:  0/TCP
    Environment:
      POSTGRES_USER:      <redacted>
      POSTGRES_PASSWORD:  <redacted>
      POSTGRES_DB:        postgresdb
    Mounts:
      /var/lib/postgresql/data from postgresdb (rw)
  Volumes:
   postgresdb:
    Type:       PersistentVolumeClaim (a reference to a PersistentVolumeClaim in the same namespace)
    ClaimName:  postgres-persistant-storage-postgres-0
    ReadOnly:   false

如前所述，只是試圖指向現有的 postgres 數據庫，而不是讓它嘗試創建和初始化一個全新的數據庫，任何幫助將不勝感激！

---

更新

當我猛擊 Postgres pod 並檢查/var/lib/postgresql/data目錄時，我確實看到了 PG_VERSION 文件以及一堆其他 db 文件（屏幕截圖）。 PG_VERSION 文件本身包含字符串11 ，這很有意義，因為我們使用的是 Postgres 11.5。 不幸的是，由於某種原因，它仍然無法識別它:(

這也是我的 deployment.yaml 規范：

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  annotations:
    deployment.kubernetes.io/revision: "60"
  creationTimestamp: "2019-08-23T22:17:44Z"
  generation: 184
  labels:
    app: postgres
  name: postgres
  namespace: wiki
  resourceVersion: "91329506"
  selfLink: /apis/extensions/v1beta1/namespaces/wiki/deployments/postgres
  uid: d441d0d8-c5f3-11e9-bc53-9676559ad387
spec:
  progressDeadlineSeconds: 2147483647
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      app: postgres
  strategy:
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 1
    type: RollingUpdate
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: postgres
    spec:
      containers:
      - env:
        - name: POSTGRES_USER
          value: postgresadmin
        - name: POSTGRES_PASSWORD
          value: <redacted>
        - name: POSTGRES_DB
          value: wiki
        image: postgres:11.5
        imagePullPolicy: IfNotPresent
        name: postgres
        ports:
        - containerPort: 5432
          protocol: TCP
        resources: {}
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
        volumeMounts:
        - mountPath: /var/lib/postgresql/data
          name: postgresdb
      dnsPolicy: ClusterFirst
      hostname: postgrespod
      restartPolicy: Always
      schedulerName: default-scheduler
      securityContext: {}
      subdomain: postgres
      terminationGracePeriodSeconds: 30
      volumes:
      - name: postgresdb
        persistentVolumeClaim:
          claimName: wiki-data

Answer 1

看起來圖像檢查的是一個名為$PGDATA/PG_VERSION的匹配文件，以決定它是否需要初始化。 見https://github.com/docker-library/postgres/blob/04f28840134bdaf72e4cd6e4a5300e9ceb5ea013/docker-entrypoint.sh#L211-L214

您必須使該文件存在於您的卷中。