---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: postgres-exporter
  namespace: monitoring
  labels:
    app: postgres-exporter
spec:
  replicas: 1
  selector:
    matchLabels:
      app: postgres-exporter
  template:
    metadata:
      labels:
        app: postgres-exporter
    spec:
      containers:
      - name: postgres-exporter
        image: prometheuscommunity/postgres-exporter:v0.15.0
        ports:
        - containerPort: 9187
          name: metrics
        env:
        - name: DATA_SOURCE_NAME
          valueFrom:
            secretKeyRef:
              name: postgres-exporter
              key: data-source-name
        # Enable extended metrics
        - name: PG_EXPORTER_EXTEND_QUERY_PATH
          value: "/etc/postgres-exporter/queries.yaml"
        # Disable default metrics (we'll use custom ones)
        - name: PG_EXPORTER_DISABLE_DEFAULT_METRICS
          value: "false"
        # Disable settings metrics (can be noisy)
        - name: PG_EXPORTER_DISABLE_SETTINGS_METRICS
          value: "false"
        volumeMounts:
        - name: queries
          mountPath: /etc/postgres-exporter
        resources:
          requests:
            memory: "64Mi"
            cpu: "50m"
          limits:
            memory: "128Mi"
            cpu: "200m"
        livenessProbe:
          httpGet:
            path: /
            port: 9187
          initialDelaySeconds: 30
          periodSeconds: 10
        readinessProbe:
          httpGet:
            path: /
            port: 9187
          initialDelaySeconds: 5
          periodSeconds: 5
      volumes:
      - name: queries
        configMap:
          name: postgres-exporter-queries

---
apiVersion: v1
kind: ConfigMap
metadata:
  name: postgres-exporter-queries
  namespace: monitoring
data:
  queries.yaml: |
    # Custom PostgreSQL queries for bakery-ia metrics

    pg_database:
      query: |
        SELECT
          datname,
          numbackends as connections,
          xact_commit as transactions_committed,
          xact_rollback as transactions_rolled_back,
          blks_read as blocks_read,
          blks_hit as blocks_hit,
          tup_returned as tuples_returned,
          tup_fetched as tuples_fetched,
          tup_inserted as tuples_inserted,
          tup_updated as tuples_updated,
          tup_deleted as tuples_deleted,
          conflicts as conflicts,
          temp_files as temp_files,
          temp_bytes as temp_bytes,
          deadlocks as deadlocks
        FROM pg_stat_database
        WHERE datname NOT IN ('template0', 'template1', 'postgres')
      metrics:
        - datname:
            usage: "LABEL"
            description: "Name of the database"
        - connections:
            usage: "GAUGE"
            description: "Number of backends currently connected to this database"
        - transactions_committed:
            usage: "COUNTER"
            description: "Number of transactions in this database that have been committed"
        - transactions_rolled_back:
            usage: "COUNTER"
            description: "Number of transactions in this database that have been rolled back"
        - blocks_read:
            usage: "COUNTER"
            description: "Number of disk blocks read in this database"
        - blocks_hit:
            usage: "COUNTER"
            description: "Number of times disk blocks were found in the buffer cache"
        - tuples_returned:
            usage: "COUNTER"
            description: "Number of rows returned by queries in this database"
        - tuples_fetched:
            usage: "COUNTER"
            description: "Number of rows fetched by queries in this database"
        - tuples_inserted:
            usage: "COUNTER"
            description: "Number of rows inserted by queries in this database"
        - tuples_updated:
            usage: "COUNTER"
            description: "Number of rows updated by queries in this database"
        - tuples_deleted:
            usage: "COUNTER"
            description: "Number of rows deleted by queries in this database"
        - conflicts:
            usage: "COUNTER"
            description: "Number of queries canceled due to conflicts with recovery"
        - temp_files:
            usage: "COUNTER"
            description: "Number of temporary files created by queries"
        - temp_bytes:
            usage: "COUNTER"
            description: "Total amount of data written to temporary files by queries"
        - deadlocks:
            usage: "COUNTER"
            description: "Number of deadlocks detected in this database"

    pg_replication:
      query: |
        SELECT
          CASE WHEN pg_is_in_recovery() THEN 1 ELSE 0 END as is_replica,
          EXTRACT(EPOCH FROM (now() - pg_last_xact_replay_timestamp()))::INT as lag_seconds
      metrics:
        - is_replica:
            usage: "GAUGE"
            description: "1 if this is a replica, 0 if primary"
        - lag_seconds:
            usage: "GAUGE"
            description: "Replication lag in seconds (only on replicas)"

    pg_slow_queries:
      query: |
        SELECT
          datname,
          usename,
          state,
          COUNT(*) as count,
          MAX(EXTRACT(EPOCH FROM (now() - query_start))) as max_duration_seconds
        FROM pg_stat_activity
        WHERE state != 'idle'
          AND query NOT LIKE '%pg_stat_activity%'
          AND query_start < now() - interval '30 seconds'
        GROUP BY datname, usename, state
      metrics:
        - datname:
            usage: "LABEL"
            description: "Database name"
        - usename:
            usage: "LABEL"
            description: "User name"
        - state:
            usage: "LABEL"
            description: "Query state"
        - count:
            usage: "GAUGE"
            description: "Number of slow queries"
        - max_duration_seconds:
            usage: "GAUGE"
            description: "Maximum query duration in seconds"

    pg_table_stats:
      query: |
        SELECT
          schemaname,
          relname,
          seq_scan,
          seq_tup_read,
          idx_scan,
          idx_tup_fetch,
          n_tup_ins,
          n_tup_upd,
          n_tup_del,
          n_tup_hot_upd,
          n_live_tup,
          n_dead_tup,
          n_mod_since_analyze,
          last_vacuum,
          last_autovacuum,
          last_analyze,
          last_autoanalyze
        FROM pg_stat_user_tables
        WHERE schemaname = 'public'
        ORDER BY n_live_tup DESC
        LIMIT 20
      metrics:
        - schemaname:
            usage: "LABEL"
            description: "Schema name"
        - relname:
            usage: "LABEL"
            description: "Table name"
        - seq_scan:
            usage: "COUNTER"
            description: "Number of sequential scans"
        - seq_tup_read:
            usage: "COUNTER"
            description: "Number of tuples read by sequential scans"
        - idx_scan:
            usage: "COUNTER"
            description: "Number of index scans"
        - idx_tup_fetch:
            usage: "COUNTER"
            description: "Number of tuples fetched by index scans"
        - n_tup_ins:
            usage: "COUNTER"
            description: "Number of tuples inserted"
        - n_tup_upd:
            usage: "COUNTER"
            description: "Number of tuples updated"
        - n_tup_del:
            usage: "COUNTER"
            description: "Number of tuples deleted"
        - n_tup_hot_upd:
            usage: "COUNTER"
            description: "Number of tuples HOT updated"
        - n_live_tup:
            usage: "GAUGE"
            description: "Estimated number of live rows"
        - n_dead_tup:
            usage: "GAUGE"
            description: "Estimated number of dead rows"
        - n_mod_since_analyze:
            usage: "GAUGE"
            description: "Number of rows modified since last analyze"

    pg_locks:
      query: |
        SELECT
          mode,
          locktype,
          COUNT(*) as count
        FROM pg_locks
        GROUP BY mode, locktype
      metrics:
        - mode:
            usage: "LABEL"
            description: "Lock mode"
        - locktype:
            usage: "LABEL"
            description: "Lock type"
        - count:
            usage: "GAUGE"
            description: "Number of locks"

    pg_connection_pool:
      query: |
        SELECT
          state,
          COUNT(*) as count,
          MAX(EXTRACT(EPOCH FROM (now() - state_change))) as max_state_duration_seconds
        FROM pg_stat_activity
        GROUP BY state
      metrics:
        - state:
            usage: "LABEL"
            description: "Connection state"
        - count:
            usage: "GAUGE"
            description: "Number of connections in this state"
        - max_state_duration_seconds:
            usage: "GAUGE"
            description: "Maximum time a connection has been in this state"

---
apiVersion: v1
kind: Service
metadata:
  name: postgres-exporter
  namespace: monitoring
  labels:
    app: postgres-exporter
spec:
  type: ClusterIP
  ports:
  - port: 9187
    targetPort: 9187
    protocol: TCP
    name: metrics
  selector:
    app: postgres-exporter