Add starting abstractions and impl for sending alerts via Gmail and Grafana

Author: NamelessOne91

alerts/alerts.go

@@ -0,0 +1,63 @@
+package alerts
+
+import (
+	"fmt"
+	"log"
+)
+
+type Alerter interface {
+	SendAlert(title, content string) error
+}
+
+type AlertsConfig struct {
+	FailOnError bool
+	Gmail       MailerConfig
+	Grafana     GrafanaConfig
+}
+
+type AlertsManager struct {
+	failOnError bool
+	alerters    []Alerter
+}
+
+func NewAlertsManager(config AlertsConfig) (*AlertsManager, error) {
+	alerters := []Alerter{}
+
+	if config.Gmail.Enabled {
+		log.Println("Initializig Gmail alerter ...")
+		gmailAlerter, err := NewGmailAlerter(config.Gmail)
+		if err != nil {
+			return nil, err
+		}
+
+		alerters = append(alerters, gmailAlerter)
+		log.Println("Gmail alerter ready")
+	}
+
+	if config.Grafana.Enabled {
+		log.Println("Initializig Grafana alerter ...")
+		grafanaAlerter := NewGrafanaAlerter(config.Grafana)
+		alerters = append(alerters, grafanaAlerter)
+		log.Println("Grafana alerter ready")
+	}
+
+	return &AlertsManager{
+		failOnError: config.FailOnError,
+		alerters:    alerters,
+	}, nil
+}
+
+func (am *AlertsManager) DispatchAlert(repo string, cause error) error {
+	title := fmt.Sprintf("Minima - failure for %s", repo)
+	content := fmt.Sprintf("Cause: %v", cause)
+
+	for _, a := range am.alerters {
+		if err := a.SendAlert(title, content); err != nil {
+			log.Printf("Alerter error: %v\n", err)
+			if am.failOnError {
+				return err
+			}
+		}
+	}
+	return nil
+}

alerts/gmail.go

@@ -0,0 +1,59 @@
+package alerts
+
+import (
+	"fmt"
+	"log"
+
+	"gopkg.in/gomail.v2"
+)
+
+const gmailSMTP = "smtp.gmail.com"
+const gmailSMTPPort = 587
+
+type MailerConfig struct {
+	Enabled    bool
+	Account    string
+	Password   string
+	From       string
+	Recipients []string
+}
+
+type GmailAlerter struct {
+	mailClient gomail.SendCloser
+	from       string
+	recipients []string
+}
+
+func NewGmailAlerter(config MailerConfig) (*GmailAlerter, error) {
+	d := gomail.NewDialer(gmailSMTP, gmailSMTPPort, config.Account, config.Password)
+	sender, err := d.Dial()
+	if err != nil {
+		return nil, err
+	}
+
+	return &GmailAlerter{
+		mailClient: sender,
+		from:       config.From,
+		recipients: config.Recipients,
+	}, nil
+}
+
+// Alerter interface implementation
+func (config *GmailAlerter) SendAlert(title, content string) error {
+	log.Printf("Sending alert via gmail to: %v\n", config.recipients)
+
+	if err := config.sendEmail(title, content); err != nil {
+		return fmt.Errorf("failed to send alert via email: %v", err)
+	}
+	return nil
+}
+
+func (config *GmailAlerter) sendEmail(subject, body string) error {
+	m := gomail.NewMessage()
+	m.SetHeader("From", config.from)
+	m.SetHeader("To", config.recipients...)
+	m.SetHeader("Subject", subject)
+	m.SetBody("text/plain", body)
+
+	return gomail.Send(config.mailClient, m)
+}

alerts/grafana.go

@@ -0,0 +1,79 @@
+package alerts
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"time"
+)
+
+type GrafanaConfig struct {
+	Enabled    bool
+	AlertTitle string
+	APIUrl     string
+	APIKey     string
+}
+
+type GrafanaAlerter struct {
+	httpClient *http.Client
+	key        string
+	alertsUrl  string
+}
+
+type AlertPayload struct {
+	Title       string `json:"title"`
+	Message     string `json:"message"`
+	AlertStatus string `json:"status"`
+}
+
+func NewGrafanaAlerter(config GrafanaConfig) *GrafanaAlerter {
+	client := &http.Client{Timeout: 30 * time.Second}
+
+	return &GrafanaAlerter{
+		httpClient: client,
+		alertsUrl:  config.APIUrl + "alerts",
+		key:        config.APIKey,
+	}
+}
+
+// Alerter interface implementation
+func (g *GrafanaAlerter) SendAlert(title, content string) error {
+	fmt.Println("Sending Grafana alert")
+
+	if err := g.postGrafanaAlert(title, content); err != nil {
+		return fmt.Errorf("failed to send Grafana alert: %v", err)
+	}
+	return nil
+}
+
+func (g *GrafanaAlerter) postGrafanaAlert(title, msg string) error {
+	alert := AlertPayload{
+		Title:       title,
+		Message:     msg,
+		AlertStatus: "alerting",
+	}
+
+	jsonData, err := json.Marshal(alert)
+	if err != nil {
+		return err
+	}
+
+	req, err := http.NewRequest("POST", g.alertsUrl, bytes.NewBuffer(jsonData))
+	if err != nil {
+		return err
+	}
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Authorization", "Bearer "+g.key)
+
+	resp, err := g.httpClient.Do(req)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("failed to send Grafana alert, status code: %d", resp.StatusCode)
+	}
+	return nil
+}