Add support for synchronous plugin installation (#92129)

pkg/services/pluginsintegration/plugininstaller/service.go

@@ -3,8 +3,10 @@ package plugininstaller
 import (
 	"context"
 	"errors"
+	"fmt"
 	"runtime"
 
+	"cuelang.org/go/pkg/time"
 	"github.com/grafana/grafana/pkg/infra/log"
 	"github.com/grafana/grafana/pkg/plugins"
 	"github.com/grafana/grafana/pkg/services/featuremgmt"
@@ -18,29 +20,57 @@ type Service struct {
 	log             log.Logger
 	pluginInstaller plugins.Installer
 	pluginStore     pluginstore.Store
+	failOnErr       bool
 }
 
-func ProvideService(cfg *setting.Cfg, features featuremgmt.FeatureToggles, pluginStore pluginstore.Store, pluginInstaller plugins.Installer) *Service {
+func ProvideService(cfg *setting.Cfg, features featuremgmt.FeatureToggles, pluginStore pluginstore.Store, pluginInstaller plugins.Installer) (*Service, error) {
 	s := &Service{
 		features:        features,
 		log:             log.New("plugin.backgroundinstaller"),
 		cfg:             cfg,
 		pluginInstaller: pluginInstaller,
 		pluginStore:     pluginStore,
+		failOnErr:       !cfg.PreinstallPluginsAsync, // Fail on error if preinstall is synchronous
 	}
-	return s
+	if !cfg.PreinstallPluginsAsync {
+		// Block initialization process until plugins are installed
+		err := s.installPluginsWithTimeout()
+		if err != nil {
+			return nil, err
+		}
+	}
+	return s, nil
 }
 
 // IsDisabled disables background installation of plugins.
 func (s *Service) IsDisabled() bool {
 	return !s.features.IsEnabled(context.Background(), featuremgmt.FlagBackgroundPluginInstaller) ||
-		len(s.cfg.InstallPlugins) == 0
+		len(s.cfg.PreinstallPlugins) == 0 ||
+		!s.cfg.PreinstallPluginsAsync
 }
 
-func (s *Service) Run(ctx context.Context) error {
+func (s *Service) installPluginsWithTimeout() error {
+	// Installation process does not timeout by default nor reuses the context
+	// passed to the request so we need to handle the timeout here.
+	// We could make this timeout configurable in the future.
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Minute)
+	defer cancel()
+	done := make(chan struct{ err error })
+	go func() {
+		done <- struct{ err error }{err: s.installPlugins(ctx)}
+	}()
+	select {
+	case <-ctx.Done():
+		return fmt.Errorf("failed to install plugins: %w", ctx.Err())
+	case d := <-done:
+		return d.err
+	}
+}
+
+func (s *Service) installPlugins(ctx context.Context) error {
 	compatOpts := plugins.NewCompatOpts(s.cfg.BuildVersion, runtime.GOOS, runtime.GOARCH)
 
-	for _, installPlugin := range s.cfg.InstallPlugins {
+	for _, installPlugin := range s.cfg.PreinstallPlugins {
 		// Check if the plugin is already installed
 		p, exists := s.pluginStore.Plugin(ctx, installPlugin.ID)
 		if exists {
@@ -59,6 +89,10 @@ func (s *Service) Run(ctx context.Context) error {
 				s.log.Debug("Plugin already installed", "pluginId", installPlugin.ID, "version", installPlugin.Version)
 				continue
 			}
+			if s.failOnErr {
+				// Halt execution in the synchronous scenario
+				return fmt.Errorf("failed to install plugin %s@%s: %w", installPlugin.ID, installPlugin.Version, err)
+			}
 			s.log.Error("Failed to install plugin", "pluginId", installPlugin.ID, "version", installPlugin.Version, "error", err)
 			continue
 		}
@@ -67,3 +101,12 @@ func (s *Service) Run(ctx context.Context) error {
 
 	return nil
 }
+
+func (s *Service) Run(ctx context.Context) error {
+	err := s.installPlugins(ctx)
+	if err != nil {
+		// Unexpected error, asynchronous installation should not return errors
+		s.log.Error("Failed to install plugins", "error", err)
+	}
+	return nil
+}