apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: postgres-data
spec:
  accessModes: [ReadWriteOnce]
  resources:
    requests:
      storage: ${POSTGRES_STORAGE:-2Gi}
---
apiVersion: v1
kind: Service
metadata:
  name: postgres
spec:
  selector:
    app: postgres
  ports:
    - port: 5432
      targetPort: 5432
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: postgres
spec:
  replicas: 1
  # One volume, one writer. Rolling would start a second pod against the same
  # PVC before the first exits, and Postgres refuses to share a data directory.
  strategy:
    type: Recreate
  selector:
    matchLabels:
      app: postgres
  template:
    metadata:
      labels:
        app: postgres
    spec:
      containers:
        - name: postgres
          image: ${POSTGRES_IMAGE}
          envFrom:
            - secretRef:
                name: postgres
          env:
            # The image initialises into the volume root otherwise, and a
            # lost+found from the PVC makes it refuse to initdb.
            - name: PGDATA
              value: /var/lib/postgresql/data/pgdata
          ports:
            - containerPort: 5432
          volumeMounts:
            - name: data
              mountPath: /var/lib/postgresql/data
          readinessProbe:
            exec:
              command: ["sh", "-c", "pg_isready -U $POSTGRES_USER -d $POSTGRES_DB"]
            initialDelaySeconds: 5
            periodSeconds: 5
          livenessProbe:
            exec:
              command: ["sh", "-c", "pg_isready -U $POSTGRES_USER -d $POSTGRES_DB"]
            initialDelaySeconds: 30
            periodSeconds: 15
      volumes:
        - name: data
          persistentVolumeClaim:
            claimName: postgres-data