first push of

pi/roverd/media_supervisor.go

@@ -0,0 +1,121 @@
+package roverd
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"os/exec"
+	"time"
+)
+
+type MediaSupervisor struct {
+	cfg           MediaConfig
+	logger        *log.Logger
+	client        *http.Client
+	checkInterval time.Duration
+}
+
+func NewMediaSupervisor(cfg MediaConfig, logger *log.Logger) *MediaSupervisor {
+	if !cfg.Manage || cfg.Service == "" {
+		return nil
+	}
+	interval := cfg.HealthInterval.Duration
+	if interval <= 0 {
+		interval = 30 * time.Second
+	}
+	return &MediaSupervisor{
+		cfg:           cfg,
+		logger:        logger,
+		client:        &http.Client{Timeout: 5 * time.Second},
+		checkInterval: interval,
+	}
+}
+
+func (m *MediaSupervisor) Start(ctx context.Context) {
+	if m == nil || m.cfg.HealthURL == "" {
+		return
+	}
+	go func() {
+		ticker := time.NewTicker(m.checkInterval)
+		defer ticker.Stop()
+
+		if err := m.checkAndRepair(); err != nil {
+			m.logger.Printf("media supervisor: %v", err)
+		}
+
+		for {
+			select {
+			case <-ctx.Done():
+				return
+			case <-ticker.C:
+				if err := m.checkAndRepair(); err != nil {
+					m.logger.Printf("media supervisor: %v", err)
+				}
+			}
+		}
+	}()
+}
+
+func (m *MediaSupervisor) HandleAction(ctx context.Context, action string) error {
+	if m == nil {
+		return errors.New("media supervisor disabled")
+	}
+	switch action {
+	case "start", "stop", "restart", "reload", "status":
+		return m.runSystemctl(ctx, action)
+	default:
+		return fmt.Errorf("unknown media action: %s", action)
+	}
+}
+
+func (m *MediaSupervisor) checkAndRepair() error {
+	ctx, cancel := context.WithTimeout(context.Background(), 7*time.Second)
+	defer cancel()
+
+	if m.checkHealth(ctx) {
+		return nil
+	}
+	m.logger.Printf("media supervisor: health check failed, restarting %s", m.cfg.Service)
+	if err := m.runSystemctl(ctx, "restart"); err != nil {
+		return fmt.Errorf("restart mediamtx: %w", err)
+	}
+	return nil
+}
+
+func (m *MediaSupervisor) checkHealth(ctx context.Context) bool {
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, m.cfg.HealthURL, nil)
+	if err != nil {
+		m.logger.Printf("media supervisor: health request: %v", err)
+		return false
+	}
+	resp, err := m.client.Do(req)
+	if err != nil {
+		m.logger.Printf("media supervisor: health request failed: %v", err)
+		return false
+	}
+	defer resp.Body.Close()
+	_, _ = io.Copy(io.Discard, resp.Body)
+	if resp.StatusCode >= 200 && resp.StatusCode < 300 {
+		return true
+	}
+	m.logger.Printf("media supervisor: unexpected health status %d", resp.StatusCode)
+	return false
+}
+
+func (m *MediaSupervisor) runSystemctl(ctx context.Context, action string) error {
+	if m.cfg.Service == "" {
+		return errors.New("no media service configured")
+	}
+	runCtx, cancel := context.WithTimeout(ctx, 15*time.Second)
+	defer cancel()
+
+	cmd := exec.CommandContext(runCtx, "systemctl", action, m.cfg.Service)
+	output, err := cmd.CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("systemctl %s %s: %w (%s)", action, m.cfg.Service, err, string(output))
+	}
+	return nil
+}