chore: import upstream snapshot with attribution

service/group.go

@@ -0,0 +1,98 @@
+package service
+
+import (
+	"context"
+	"os"
+	"os/signal"
+	"sync"
+
+	signalutil "go-micro.dev/v6/internal/util/signal"
+	log "go-micro.dev/v6/logger"
+)
+
+// Group runs multiple services in a single binary with shared
+// lifecycle management. All services start together and stop
+// together on signal or context cancellation.
+type Group struct {
+	services []Service
+	logger   log.Logger
+}
+
+// NewGroup creates a new service group.
+func NewGroup(svcs ...Service) *Group {
+	return &Group{
+		services: svcs,
+		logger:   log.DefaultLogger,
+	}
+}
+
+// Add appends one or more services to the group.
+func (g *Group) Add(svcs ...Service) {
+	g.services = append(g.services, svcs...)
+}
+
+// Run starts all services concurrently and blocks until a signal
+// is received or the context is canceled, then stops all services.
+func (g *Group) Run() error {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	// Initialize all services. Disable per-service signal handling
+	// since the group manages signals.
+	for _, svc := range g.services {
+		svc.Init(HandleSignal(false))
+	}
+
+	g.logger.Logf(log.InfoLevel, "Starting service group with %d services", len(g.services))
+
+	// Start all services
+	errCh := make(chan error, len(g.services))
+	for _, svc := range g.services {
+		g.logger.Logf(log.InfoLevel, "Starting [service] %s", svc.Name())
+		if err := svc.Start(); err != nil {
+			cancel()
+			_ = g.stopAll()
+			return err
+		}
+	}
+
+	// Wait for signal or context cancellation
+	ch := make(chan os.Signal, 1)
+	signal.Notify(ch, signalutil.Shutdown()...)
+
+	select {
+	case <-ch:
+		g.logger.Logf(log.InfoLevel, "Received signal, stopping all services")
+	case <-ctx.Done():
+	case err := <-errCh:
+		cancel()
+		_ = g.stopAll()
+		return err
+	}
+
+	return g.stopAll()
+}
+
+func (g *Group) stopAll() error {
+	var (
+		mu      sync.Mutex
+		lastErr error
+	)
+
+	var wg sync.WaitGroup
+	for _, svc := range g.services {
+		wg.Add(1)
+		go func(s Service) {
+			defer wg.Done()
+			g.logger.Logf(log.InfoLevel, "Stopping [service] %s", s.Name())
+			if err := s.Stop(); err != nil {
+				mu.Lock()
+				lastErr = err
+				mu.Unlock()
+			}
+		}(svc)
+	}
+	wg.Wait()
+
+	return lastErr
+}