Add infrastructure reliability monitoring

store.go

@@ -7,6 +7,7 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+	"sync"
 	"time"
 
 	_ "modernc.org/sqlite"
@@ -58,7 +59,13 @@ type HistoryPoint struct {
 	GuestsMemory    float64  `json:"guestsMemory"`
 }
 
-type Store struct{ db *sql.DB }
+type Store struct {
+	db               *sql.DB
+	path             string
+	healthMu         sync.RWMutex
+	lastHistoryAt    time.Time
+	lastHistoryError string
+}
 
 type EmailSettings struct {
 	Enabled         bool     `json:"enabled"`
@@ -130,7 +137,7 @@ func openStore(path string) (*Store, error) {
 	_, _ = db.Exec(`ALTER TABLE alert_events ADD COLUMN recovery_sent_at INTEGER`)
 	_, _ = db.Exec(`ALTER TABLE service_checks ADD COLUMN endpoint TEXT NOT NULL DEFAULT 'public'`)
 	_, _ = db.Exec(`PRAGMA foreign_keys=ON`)
-	return &Store{db: db}, nil
+	return &Store{db: db, path: path}, nil
 }
 
 type EntityHistoryPoint struct {
@@ -285,9 +292,45 @@ func (s *Store) AddHistory(point HistoryPoint) error {
 	_, err := s.db.Exec(`INSERT OR REPLACE INTO history(ts,cpu_usage,cpu_temp,memory_usage,swap_usage,root_usage,network_rx,network_tx,ups_charge,ups_load,zfs_usage,guests_cpu,guests_memory) VALUES(?,?,?,?,?,?,?,?,?,?,?,?,?)`,
 		point.Timestamp, point.CPUUsage, point.CPUTemperature, point.MemoryUsage, point.SwapUsage, point.RootUsage, point.NetworkReceive, point.NetworkTransmit, point.UPSCharge, point.UPSLoad, point.ZFSUsage, point.GuestsCPU, point.GuestsMemory)
 	if err != nil {
+		s.setHistoryHealth(time.Time{}, err)
 		return err
 	}
 	_, err = s.db.Exec(`DELETE FROM history WHERE ts < ?`, time.Now().Add(-historyRetention).Unix())
+	s.setHistoryHealth(time.Now(), err)
+	return err
+}
+
+func (s *Store) setHistoryHealth(at time.Time, err error) {
+	s.healthMu.Lock()
+	defer s.healthMu.Unlock()
+	if !at.IsZero() {
+		s.lastHistoryAt = at
+	}
+	if err != nil {
+		s.lastHistoryError = err.Error()
+	} else {
+		s.lastHistoryError = ""
+	}
+}
+func (s *Store) historyHealth() (time.Time, string) {
+	s.healthMu.RLock()
+	defer s.healthMu.RUnlock()
+	return s.lastHistoryAt, s.lastHistoryError
+}
+
+func (s *Store) loadJSONSetting(key string, target any) bool {
+	var value string
+	if s.db.QueryRow(`SELECT value FROM settings WHERE key=?`, key).Scan(&value) != nil {
+		return false
+	}
+	return json.Unmarshal([]byte(value), target) == nil
+}
+func (s *Store) saveJSONSetting(key string, value any) error {
+	data, err := json.Marshal(value)
+	if err != nil {
+		return err
+	}
+	_, err = s.db.Exec(`INSERT INTO settings(key,value) VALUES(?,?) ON CONFLICT(key) DO UPDATE SET value=excluded.value`, key, string(data))
 	return err
 }