apiVersion: v1
kind: Service
metadata:
  name: postgres
  namespace: phoenix
  labels:
    app: postgres
spec:
  type: ClusterIP
  ports:
    - port: 5432
      targetPort: 5432
      name: postgres
  selector:
    app: postgres
  clusterIP: None  # Headless service for StatefulSet
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: postgres
  namespace: phoenix
  labels:
    app: postgres
spec:
  serviceName: postgres
  replicas: 1
  selector:
    matchLabels:
      app: postgres
  template:
    metadata:
      labels:
        app: postgres
    spec:
      # Prevent scheduling on Raspberry Pi due to resource requirements (256Mi-1Gi memory, 250m-1000m CPU)
      nodeSelector:
        hardware: high-memory
      containers:
        - name: postgres
          image: postgres:16
          ports:
            - containerPort: 5432
              name: postgres
          env:
            - name: POSTGRES_USER
              valueFrom:
                secretKeyRef:
                  name: phoenix-secret
                  key: POSTGRES_USER
            - name: POSTGRES_PASSWORD
              valueFrom:
                secretKeyRef:
                  name: phoenix-secret
                  key: POSTGRES_PASSWORD
            - name: POSTGRES_DB
              valueFrom:
                secretKeyRef:
                  name: phoenix-secret
                  key: POSTGRES_DB
            - name: PGDATA
              value: /var/lib/postgresql/data/pgdata
            # PostgreSQL optimization settings
            - name: POSTGRES_INITDB_ARGS
              value: "-E UTF8"
          args:
            - "postgres"
            - "-c"
            - "shared_preload_libraries=pg_stat_statements"
            - "-c"
            - "pg_stat_statements.track=all"
            - "-c"
            - "shared_buffers=256MB"
            - "-c"
            - "effective_cache_size=1GB"
            - "-c"
            - "maintenance_work_mem=128MB"
            - "-c"
            - "checkpoint_completion_target=0.9"
            - "-c"
            - "wal_buffers=16MB"
            - "-c"
            - "default_statistics_target=100"
            - "-c"
            - "random_page_cost=1.1"
            - "-c"
            - "effective_io_concurrency=200"
            - "-c"
            - "work_mem=8MB"
            - "-c"
            - "min_wal_size=1GB"
            - "-c"
            - "max_wal_size=4GB"
          volumeMounts:
            - name: postgres-data
              mountPath: /var/lib/postgresql/data
          resources:
            requests:
              memory: "256Mi"
              cpu: "250m"
            limits:
              memory: "1Gi"
              cpu: "1000m"
          readinessProbe:
            exec:
              command:
                - /bin/sh
                - -c
                - pg_isready -U postgres
            initialDelaySeconds: 10
            periodSeconds: 10
            timeoutSeconds: 5
            successThreshold: 1
            failureThreshold: 3
          livenessProbe:
            exec:
              command:
                - /bin/sh
                - -c
                - pg_isready -U postgres
            initialDelaySeconds: 30
            periodSeconds: 30
            timeoutSeconds: 5
            successThreshold: 1
            failureThreshold: 3
  volumeClaimTemplates:
    - metadata:
        name: postgres-data
      spec:
        accessModes: ["ReadWriteOnce"]
        resources:
          requests:
            storage: 8Gi