split daemon request and runtime setup

main.go

@@ -9,6 +9,7 @@ import (
 	"flag"
 	"fmt"
 	"io"
+	"log/slog"
 	"net/http"
 	"os"
 	"os/signal"
@@ -342,34 +343,9 @@ func runServe(ctx context.Context) (result error) {
 		return err
 	}
 	httpClient := &http.Client{Timeout: 5 * time.Second}
-	var updater *backendupdate.Updater
-	var diagnoser *backendstatus.Diagnoser
-	switch config.Backend.Type {
-	case deploymentconfig.BackendTypeNative:
-		releaseStore, err := filestore.New(config.Backend.ReleaseDir)
-		if err != nil {
-			return err
-		}
-		units, err := systemd.NewSystemctl(config.Backend.SystemctlPath)
-		if err != nil {
-			return err
-		}
-		updater, err = backendupdate.New(config, runtimepaths.WorkRoot, store, coordinator, releaseStore, units, gateway, httpClient, logger)
-		if err == nil {
-			diagnoser, err = backendstatus.New(config, store, coordinator, nil, units, gateway)
-		}
-	case deploymentconfig.BackendTypeContainer:
-		var engine *containerengine.MobyEngine
-		engine, err = containerengine.NewMobyEngine()
-		if err == nil {
-			defer func() { result = errors.Join(result, engine.Close()) }()
-			updater, err = backendupdate.NewContainer(config, runtimepaths.WorkRoot, store, coordinator, engine, gateway, httpClient, logger)
-			if err == nil {
-				diagnoser, err = backendstatus.New(config, store, coordinator, engine, nil, gateway)
-			}
-		}
-	default:
-		err = fmt.Errorf("unsupported backend.type %q", config.Backend.Type)
+	updater, diagnoser, closeRuntime, err := buildRuntime(config, store, coordinator, gateway, httpClient, logger)
+	if closeRuntime != nil {
+		defer func() { result = errors.Join(result, closeRuntime()) }()
 	}
 	if err != nil {
 		return err
@@ -381,6 +357,50 @@ func runServe(ctx context.Context) (result error) {
 	return server.Serve(ctx)
 }
 
+type runtimeCloser func() error
+
+func buildRuntime(config deploymentconfig.Config, store *transaction.Store, coordinator *transaction.Coordinator, gateway *hostnginx.Controller, httpClient *http.Client, logger *slog.Logger) (*backendupdate.Updater, *backendstatus.Diagnoser, runtimeCloser, error) {
+	switch config.Backend.Type {
+	case deploymentconfig.BackendTypeNative:
+		return buildNativeRuntime(config, store, coordinator, gateway, httpClient, logger)
+	case deploymentconfig.BackendTypeContainer:
+		return buildContainerRuntime(config, store, coordinator, gateway, httpClient, logger)
+	default:
+		return nil, nil, nil, fmt.Errorf("unsupported backend.type %q", config.Backend.Type)
+	}
+}
+
+func buildNativeRuntime(config deploymentconfig.Config, store *transaction.Store, coordinator *transaction.Coordinator, gateway *hostnginx.Controller, httpClient *http.Client, logger *slog.Logger) (*backendupdate.Updater, *backendstatus.Diagnoser, runtimeCloser, error) {
+	releaseStore, err := filestore.New(config.Backend.ReleaseDir)
+	if err != nil {
+		return nil, nil, nil, err
+	}
+	units, err := systemd.NewSystemctl(config.Backend.SystemctlPath)
+	if err != nil {
+		return nil, nil, nil, err
+	}
+	updater, err := backendupdate.New(config, runtimepaths.WorkRoot, store, coordinator, releaseStore, units, gateway, httpClient, logger)
+	if err != nil {
+		return nil, nil, nil, err
+	}
+	diagnoser, err := backendstatus.New(config, store, coordinator, nil, units, gateway)
+	return updater, diagnoser, nil, err
+}
+
+func buildContainerRuntime(config deploymentconfig.Config, store *transaction.Store, coordinator *transaction.Coordinator, gateway *hostnginx.Controller, httpClient *http.Client, logger *slog.Logger) (*backendupdate.Updater, *backendstatus.Diagnoser, runtimeCloser, error) {
+	engine, err := containerengine.NewMobyEngine()
+	if err != nil {
+		return nil, nil, nil, err
+	}
+	closeEngine := runtimeCloser(engine.Close)
+	updater, err := backendupdate.NewContainer(config, runtimepaths.WorkRoot, store, coordinator, engine, gateway, httpClient, logger)
+	if err != nil {
+		return nil, nil, closeEngine, err
+	}
+	diagnoser, err := backendstatus.New(config, store, coordinator, engine, nil, gateway)
+	return updater, diagnoser, closeEngine, err
+}
+
 // writeUsage 向 output 写出命令行客户端各子命令的用法说明。
 func writeUsage(output io.Writer) {
 	fmt.Fprintln(output, "usage:")