Add configurable email notification digests

email.go

@@ -0,0 +1,130 @@
+package main
+
+import (
+	"crypto/tls"
+	"fmt"
+	"log"
+	"net"
+	"net/smtp"
+	"sort"
+	"strings"
+	"time"
+)
+
+func filterEmailAlerts(alerts []Alert, settings EmailSettings) []Alert {
+	allowedSeverity, allowedSource := map[string]bool{}, map[string]bool{}
+	for _, value := range settings.Severities {
+		allowedSeverity[value] = true
+	}
+	for _, value := range settings.Sources {
+		allowedSource[value] = true
+	}
+	var result []Alert
+	for _, alert := range alerts {
+		if allowedSeverity[alert.Severity] && allowedSource[alert.Source] {
+			result = append(result, alert)
+		}
+	}
+	return result
+}
+
+func sendAlertEmail(settings EmailSettings, alerts []Alert, test bool) error {
+	subject := "Proxmox Dashboard: сводка уведомлений"
+	body := "Система не обнаружила выбранных активных событий."
+	if test {
+		subject = "Proxmox Dashboard: тест почты"
+		body = "Почтовые уведомления настроены правильно."
+	}
+	if len(alerts) > 0 {
+		groups := map[string][]Alert{}
+		for _, alert := range alerts {
+			groups[alert.Severity] = append(groups[alert.Severity], alert)
+		}
+		var lines []string
+		for _, severity := range []string{"critical", "warning", "info"} {
+			items := groups[severity]
+			if len(items) == 0 {
+				continue
+			}
+			title := map[string]string{"critical": "КРИТИЧЕСКИЕ", "warning": "ПРЕДУПРЕЖДЕНИЯ", "info": "ИНФОРМАЦИЯ"}[severity]
+			lines = append(lines, title)
+			sort.Slice(items, func(i, j int) bool { return items[i].Title < items[j].Title })
+			for _, item := range items {
+				lines = append(lines, fmt.Sprintf("• [%s] %s\n  %s", item.Source, item.Title, item.Message))
+			}
+		}
+		body = strings.Join(lines, "\n\n")
+		subject = fmt.Sprintf("Proxmox Dashboard: событий — %d", len(alerts))
+	}
+	message := []byte("From: " + settings.From + "\r\nTo: " + settings.To + "\r\nSubject: " + subject + "\r\nMIME-Version: 1.0\r\nContent-Type: text/plain; charset=UTF-8\r\nContent-Transfer-Encoding: 8bit\r\n\r\n" + body + "\r\n")
+	address := net.JoinHostPort(settings.Host, fmt.Sprint(settings.Port))
+	var client *smtp.Client
+	if settings.Port == 465 {
+		connection, err := tls.Dial("tcp", address, &tls.Config{ServerName: settings.Host, MinVersion: tls.VersionTLS12})
+		if err != nil {
+			return err
+		}
+		client, err = smtp.NewClient(connection, settings.Host)
+		if err != nil {
+			return err
+		}
+	} else {
+		var err error
+		client, err = smtp.Dial(address)
+		if err != nil {
+			return err
+		}
+		if ok, _ := client.Extension("STARTTLS"); ok {
+			if err = client.StartTLS(&tls.Config{ServerName: settings.Host, MinVersion: tls.VersionTLS12}); err != nil {
+				return err
+			}
+		}
+	}
+	defer client.Close()
+	if settings.Username != "" {
+		if err := client.Auth(smtp.PlainAuth("", settings.Username, settings.Password, settings.Host)); err != nil {
+			return err
+		}
+	}
+	if err := client.Mail(settings.From); err != nil {
+		return err
+	}
+	if err := client.Rcpt(settings.To); err != nil {
+		return err
+	}
+	writer, err := client.Data()
+	if err != nil {
+		return err
+	}
+	if _, err = writer.Write(message); err != nil {
+		return err
+	}
+	if err = writer.Close(); err != nil {
+		return err
+	}
+	return client.Quit()
+}
+
+func runEmailNotifier(collect func() (dashboardMetrics, error), store *Store) {
+	ticker := time.NewTicker(time.Minute)
+	defer ticker.Stop()
+	for range ticker.C {
+		settings := store.EmailSettings(true)
+		if !settings.Enabled || time.Since(store.LastEmailAt()) < time.Duration(settings.IntervalMinutes)*time.Minute {
+			continue
+		}
+		metrics, err := collect()
+		if err != nil {
+			continue
+		}
+		alerts := filterEmailAlerts(metrics.Alerts, settings)
+		if len(alerts) == 0 {
+			continue
+		}
+		if err := sendAlertEmail(settings, alerts, false); err != nil {
+			log.Printf("Не удалось отправить почтовую сводку: %v", err)
+			continue
+		}
+		store.SetLastEmailAt(time.Now())
+	}
+}