feat: add daily heartbeat request for counting Pocket ID instances (#578)

backend/internal/job/analytics_job.go

@@ -0,0 +1,61 @@
+package job
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+
+	"github.com/pocket-id/pocket-id/backend/internal/common"
+	"github.com/pocket-id/pocket-id/backend/internal/service"
+)
+
+const heartbeatUrl = "https://analytics.pocket-id.org/heartbeat"
+
+func (s *Scheduler) RegisterAnalyticsJob(ctx context.Context, appConfig *service.AppConfigService, httpClient *http.Client) error {
+	jobs := &AnalyticsJob{appConfig: appConfig, httpClient: httpClient}
+	return s.registerJob(ctx, "SendHeartbeat", "0 0 * * *", jobs.sendHeartbeat, true)
+}
+
+type AnalyticsJob struct {
+	appConfig  *service.AppConfigService
+	httpClient *http.Client
+}
+
+// sendHeartbeat sends a heartbeat to the analytics service
+func (j *AnalyticsJob) sendHeartbeat(ctx context.Context) error {
+	// Skip if analytics are disabled or not in production environment
+	if common.EnvConfig.AnalyticsDisabled || common.EnvConfig.AppEnv != "production" {
+		return nil
+	}
+
+	body := struct {
+		Version    string `json:"version"`
+		InstanceID string `json:"instance_id"`
+	}{
+		Version:    common.Version,
+		InstanceID: j.appConfig.GetDbConfig().InstanceID.Value,
+	}
+	bodyBytes, err := json.Marshal(body)
+	if err != nil {
+		return fmt.Errorf("failed to marshal heartbeat body: %w", err)
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, heartbeatUrl, bytes.NewBuffer(bodyBytes))
+	if err != nil {
+		return fmt.Errorf("failed to create heartbeat request: %w", err)
+	}
+	req.Header.Set("Content-Type", "application/json")
+	resp, err := j.httpClient.Do(req)
+	if err != nil {
+		return fmt.Errorf("failed to send heartbeat request: %w", err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("heartbeat request failed with status code: %d", resp.StatusCode)
+	}
+
+	return nil
+
+}