improve shutdown and app service boilerplate

main.go

@@ -15,20 +15,29 @@ import (
 	"fmt"
 	"os"
 	"os/signal"
+	"sync"
+	"time"
 
-	"github.com/rs/zerolog/log"
+	"github.com/rs/zerolog"
 	"golang.org/x/sys/unix"
 
 	"gitea.libretechconsulting.com/rmcguire/go-app/pkg/app"
-	optsgrpc "gitea.libretechconsulting.com/rmcguire/go-app/pkg/srv/grpc/opts"
-	optshttp "gitea.libretechconsulting.com/rmcguire/go-app/pkg/srv/http/opts"
 
 	"gitea.libretechconsulting.com/rmcguire/go-server-with-otel/pkg/config"
-	"gitea.libretechconsulting.com/rmcguire/go-server-with-otel/pkg/demogrpc"
-	"gitea.libretechconsulting.com/rmcguire/go-server-with-otel/pkg/demohttp"
+	"gitea.libretechconsulting.com/rmcguire/go-server-with-otel/pkg/demo"
+	"gitea.libretechconsulting.com/rmcguire/go-server-with-otel/pkg/service"
 )
 
-var flagSchema bool
+const terminationGracePeriod = 30 * time.Second
+
+var (
+	flagSchema bool
+
+	// TODO: Register your service.AppService implementers here
+	appServices = []service.AppService{
+		&demo.DemoService{},
+	}
+)
 
 func main() {
 	ctx, cncl := signal.NotifyContext(context.Background(), os.Interrupt, unix.SIGTERM)
@@ -37,7 +46,9 @@ func main() {
 	// Load configuration and setup logging. The go-app framework
 	// will handle loading config and environment into our demo
 	// app config struct which embeds app.AooConfig
-	ctx, demoApp := app.MustLoadConfigInto(ctx, &config.DemoConfig{})
+	ctx, serviceConfig := app.MustLoadConfigInto(ctx, &config.ServiceConfig{})
+
+	log := zerolog.Ctx(ctx)
 
 	// Print schema if that's all we have to do
 	if flagSchema {
@@ -45,32 +56,50 @@ func main() {
 		os.Exit(1)
 	}
 
-	log.Debug().Any("demoAppMergedConfig", demoApp).Msg("demo app config prepared")
+	log.Debug().Any("mergedConfig", serviceConfig).Msg("App configuration prepared")
 
-	// Prepare servers
-	demoHTTP := demohttp.NewDemoHTTPServer(ctx, demoApp)
-	demoGRPC := demogrpc.NewDemoGRPCServer(ctx, demoApp)
+	// Prepare services
+	var err error
+	sdFuncs := make([]service.ShutdownFunc, len(appServices))
+	for i, svc := range appServices {
+		sdFuncs[i], err = svc.Init(ctx, serviceConfig)
+		if err != nil {
+			log.Fatal().Err(err).Send()
+		}
+	}
 
-	// Prepare app
+	// Merge all service implementations for app
+	grpcSvcs, httpSvcs := service.MergeServices(ctx, appServices...)
+
+	// Prepare app with all merged services
 	app := &app.App{
 		AppContext: ctx,
-		GRPC: &optsgrpc.AppGRPC{
-			Services:     demoGRPC.GetServices(),
-			GRPCDialOpts: demoGRPC.GetDialOpts(),
-		},
-		HTTP: &optshttp.AppHTTP{
-			Ctx:          ctx,
-			HealthChecks: demoHTTP.GetHealthCheckFuncs(),
-			Funcs:        demoHTTP.GetHandleFuncs(),
-		},
+		GRPC:       grpcSvcs,
+		HTTP:       httpSvcs,
 	}
 
 	// Launch app
 	app.MustRun()
 
-	// Wait for app to complete
-	// Perform any extra shutdown here
+	// Wait for app to complete and then perform internal shutdown
 	<-app.Done()
+
+	log.Info().Int("numServices", len(appServices)).Msg("shutting down app services")
+
+	sdCtx, cncl := context.WithTimeout(context.Background(), terminationGracePeriod)
+	defer cncl()
+
+	// Call registered shutdown funcs from all services
+	var sdWg sync.WaitGroup
+	for _, sdFunc := range sdFuncs {
+		sdWg.Add(1)
+		go func() {
+			defer sdWg.Done()
+			svcName, err := sdFunc(sdCtx)
+			log.Err(err).Str("service", svcName).Msg("terminated")
+		}()
+	}
+	sdWg.Wait()
 }
 
 // flag.Parse will be called by go-app
@@ -79,7 +108,7 @@ func init() {
 }
 
 func printSchema() {
-	bytes, err := app.CustomSchema(&config.DemoConfig{})
+	bytes, err := app.CustomSchema(&config.ServiceConfig{})
 	if err != nil {
 		panic(err)
 	}