feat: persist logs to DB, load on startup

cmd/goupkeep/main.go

@@ -260,6 +260,7 @@ func runServe(args []string) {
 	defer cancel()
 
 	eng.InitHistory()
+	eng.InitLogs()
 	eng.Start(ctx)
 
 	server.Start(server.ServerConfig{

internal/metrics/prometheus_test.go

@@ -50,6 +50,8 @@ func (m *mockStore) GetNode(string) (models.ProbeNode, error)         { return m
 func (m *mockStore) GetAllNodes() ([]models.ProbeNode, error)         { return nil, nil }
 func (m *mockStore) UpdateNodeLastSeen(string) error                  { return nil }
 func (m *mockStore) DeleteNode(string) error                          { return nil }
+func (m *mockStore) SaveLog(string) error                             { return nil }
+func (m *mockStore) LoadLogs(int) ([]string, error)                   { return nil, nil }
 
 func TestMetricsHandler(t *testing.T) {
 	ms := &mockStore{

internal/monitor/monitor.go

@@ -68,6 +68,20 @@ func (e *Engine) AddLog(msg string) {
 	if len(e.logStore) > 100 {
 		e.logStore = e.logStore[:100]
 	}
+	go func() { _ = e.db.SaveLog(entry) }()
+}
+
+func (e *Engine) InitLogs() {
+	logs, err := e.db.LoadLogs(100)
+	if err != nil {
+		return
+	}
+	if len(logs) == 0 {
+		return
+	}
+	e.logMu.Lock()
+	defer e.logMu.Unlock()
+	e.logStore = logs
 }
 
 func (e *Engine) GetLogs() []string {

internal/store/postgres.go

@@ -51,6 +51,11 @@ func (d *PostgresDialect) CreateTablesSQL() []string {
 			last_seen TIMESTAMP DEFAULT NOW(),
 			version TEXT DEFAULT ''
 		)`,
+		`CREATE TABLE IF NOT EXISTS logs (
+			id SERIAL PRIMARY KEY,
+			message TEXT NOT NULL,
+			created_at TIMESTAMP DEFAULT NOW()
+		)`,
 	}
 }
 

internal/store/sqlite.go

@@ -51,6 +51,11 @@ func (d *SQLiteDialect) CreateTablesSQL() []string {
 			last_seen DATETIME DEFAULT CURRENT_TIMESTAMP,
 			version TEXT DEFAULT ''
 		)`,
+		`CREATE TABLE IF NOT EXISTS logs (
+			id INTEGER PRIMARY KEY AUTOINCREMENT,
+			message TEXT NOT NULL,
+			created_at DATETIME DEFAULT CURRENT_TIMESTAMP
+		)`,
 	}
 }
 

internal/store/sqlstore.go

@@ -300,6 +300,34 @@ func (s *SQLStore) DeleteNode(id string) error {
 	return err
 }
 
+func (s *SQLStore) SaveLog(message string) error {
+	_, err := s.db.Exec(s.q("INSERT INTO logs (message) VALUES (?)"), message)
+	if err != nil {
+		return err
+	}
+	_, err = s.db.Exec(s.q(`DELETE FROM logs WHERE id NOT IN (
+		SELECT id FROM logs ORDER BY created_at DESC LIMIT 200
+	)`))
+	return err
+}
+
+func (s *SQLStore) LoadLogs(limit int) ([]string, error) {
+	rows, err := s.db.Query(s.q("SELECT message FROM logs ORDER BY created_at DESC LIMIT ?"), limit)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var logs []string
+	for rows.Next() {
+		var msg string
+		if err := rows.Scan(&msg); err != nil {
+			return logs, err
+		}
+		logs = append(logs, msg)
+	}
+	return logs, rows.Err()
+}
+
 func (s *SQLStore) LoadAllHistory(limit int) (map[int][]models.CheckRecord, error) {
 	result := make(map[int][]models.CheckRecord)
 	rows, err := s.db.Query(s.q(`

internal/store/store.go

@@ -45,6 +45,10 @@ type Store interface {
 	UpdateNodeLastSeen(id string) error
 	DeleteNode(id string) error
 
+	// Logs
+	SaveLog(message string) error
+	LoadLogs(limit int) ([]string, error)
+
 	// Backup & Restore
 	ExportData() (models.Backup, error)
 	ImportData(data models.Backup) error