feat(lifecycle): supervise modules and managed workers

lifecycle/example_test.go

@@ -0,0 +1,102 @@
+package lifecycle_test
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"log/slog"
+	"os"
+	"syscall"
+	"testing"
+	"time"
+
+	"go.auvem.com/corestack/lifecycle"
+)
+
+func TestRealFlow(t *testing.T) {
+	for _, failure := range []bool{false, true} {
+		t.Run(fmt.Sprint(failure), func(t *testing.T) {
+			signals := make(chan os.Signal, 2)
+			app, err := lifecycle.New(lifecycle.Config{Logger: slog.New(slog.NewTextHandler(io.Discard, nil)), Signals: signals, ShutdownTimeout: time.Second})
+			if err != nil {
+				t.Fatal(err)
+			}
+			ready := make(chan struct{}, 3)
+			release := make(chan struct{})
+			t.Cleanup(func() {
+				select {
+				case <-release:
+				default:
+					close(release)
+				}
+			})
+			failed := errors.New("service failed")
+			for _, name := range []string{"daemon", "muxer"} {
+				err = app.Register(lifecycle.Module{Name: name, Setup: func(ctx context.Context) error {
+					if name == "daemon" {
+						return app.Go(ctx, "queue", func(ctx context.Context) error { ready <- struct{}{}; <-ctx.Done(); <-release; return ctx.Err() })
+					}
+					return nil
+				}, Run: func(ctx context.Context) error {
+					ready <- struct{}{}
+					if name == "muxer" && failure {
+						<-release
+						return failed
+					}
+					<-ctx.Done()
+					return ctx.Err()
+				}, Teardown: func(context.Context) error { return nil }})
+				if err != nil {
+					t.Fatal(err)
+				}
+			}
+			done := make(chan error, 1)
+			go func() { done <- app.Run(context.Background()) }()
+			for range 3 {
+				select {
+				case <-ready:
+				case <-time.After(3 * time.Second):
+					t.Fatal("services did not start")
+				}
+			}
+			if !failure {
+				signals <- syscall.SIGTERM
+			}
+			close(release)
+			select {
+			case err = <-done:
+				if failure && !errors.Is(err, failed) || !failure && err != nil {
+					t.Fatalf("Run: %v", err)
+				}
+			case <-time.After(2 * time.Second):
+				t.Fatal("Run blocked")
+			}
+		})
+	}
+}
+
+func Example() {
+	signals := make(chan os.Signal, 2)
+	app, err := lifecycle.New(lifecycle.Config{Logger: slog.New(slog.NewTextHandler(io.Discard, nil)), Signals: signals})
+	if err != nil {
+		panic(err)
+	}
+	ready := make(chan struct{}, 2)
+	for _, name := range []string{"daemon", "muxer"} {
+		err := app.Register(lifecycle.Module{
+			Name: name,
+			Setup: func(ctx context.Context) error {
+				return app.Go(ctx, name+" worker", func(ctx context.Context) error { <-ctx.Done(); return ctx.Err() })
+			},
+			Run:      func(ctx context.Context) error { ready <- struct{}{}; <-ctx.Done(); return ctx.Err() },
+			Teardown: func(context.Context) error { return nil },
+		})
+		if err != nil {
+			panic(err)
+		}
+	}
+	go func() { <-ready; <-ready; signals <- syscall.SIGTERM }()
+	fmt.Println(app.Run(context.Background()))
+	// Output: <nil>
+}