# Postgres 17, StatefulSet + headless Service.
#
# StatefulSet rather than Deployment for the stable pod name and a PVC that
# survives the pod.
---
apiVersion: v1
kind: Service
metadata:
  name: nereus-postgres
  labels:
    app.kubernetes.io/name: nereus-postgres
    app.kubernetes.io/part-of: nereus
spec:
  clusterIP: None
  selector:
    app.kubernetes.io/name: nereus-postgres
  ports:
    - name: postgres
      port: 5432
      targetPort: postgres
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: nereus-postgres
  labels:
    app.kubernetes.io/name: nereus-postgres
    app.kubernetes.io/part-of: nereus
spec:
  serviceName: nereus-postgres
  replicas: 1
  selector:
    matchLabels:
      app.kubernetes.io/name: nereus-postgres
  template:
    metadata:
      labels:
        app.kubernetes.io/name: nereus-postgres
        app.kubernetes.io/part-of: nereus
    spec:
      securityContext:
        # postgres:17-alpine runs as uid 70. The Debian tags use 999.
        runAsUser: 70
        runAsGroup: 70
        fsGroup: 70
        runAsNonRoot: true
        seccompProfile:
          type: RuntimeDefault
      containers:
        - name: postgres
          image: postgres:17-alpine
          ports:
            - name: postgres
              containerPort: 5432
          env:
            - name: POSTGRES_DB
              value: nereus
            - name: POSTGRES_USER
              value: nereus
            - name: POSTGRES_PASSWORD
              valueFrom:
                secretKeyRef:
                  name: nereus-db
                  key: POSTGRES_PASSWORD
            # Subdirectory, or initdb trips over lost+found on the volume.
            - name: PGDATA
              value: /var/lib/postgresql/data/pgdata
          volumeMounts:
            - name: data
              mountPath: /var/lib/postgresql/data
            - name: runtime
              mountPath: /var/run/postgresql
            - name: tmp
              mountPath: /tmp
          readinessProbe:
            exec:
              command: ["pg_isready", "-U", "nereus", "-d", "nereus"]
            initialDelaySeconds: 5
            periodSeconds: 5
            timeoutSeconds: 3
            failureThreshold: 6
          livenessProbe:
            exec:
              command: ["pg_isready", "-U", "nereus", "-d", "nereus"]
            initialDelaySeconds: 30
            periodSeconds: 15
            timeoutSeconds: 5
            failureThreshold: 3
          securityContext:
            allowPrivilegeEscalation: false
            capabilities:
              drop: ["ALL"]
            readOnlyRootFilesystem: true
          resources:
            requests:
              cpu: 100m
              memory: 256Mi
            limits:
              memory: 1Gi
      volumes:
        - name: runtime
          emptyDir: {}
        - name: tmp
          emptyDir:
            sizeLimit: 64Mi
  volumeClaimTemplates:
    - metadata:
        name: data
      spec:
        accessModes: ["ReadWriteOnce"]
        resources:
          requests:
            storage: 5Gi