Restart Flamenco Manager when the first-time wizard is complete

cmd/flamenco-manager/main.go

@@ -77,11 +77,30 @@ func main() {
 		return
 	}
 
-	// The main context determines the lifetime of the application. All
-	// long-running goroutines need to keep an eye on this, and stop their work
-	// once it closes.
-	mainCtx, mainCtxCancel := context.WithCancel(context.Background())
+	startFlamenco := true
+	for startFlamenco {
+		startFlamenco = runFlamencoManager()
 
+		// After the first run, the first-time wizard should not be forced any more.
+		// If the configuration is still incomplete it can still auto-trigger.
+		cliArgs.firstTimeWizard = false
+
+		if startFlamenco {
+			log.Info().
+				Str("version", appinfo.ApplicationVersion).
+				Str("os", runtime.GOOS).
+				Str("arch", runtime.GOARCH).
+				Msgf("restarting %v", appinfo.ApplicationName)
+		}
+	}
+
+	log.Info().Msg("stopping the Flamenco Manager process")
+}
+
+// runFlamencoManager starts the entire Flamenco Manager, and only returns after
+// it has been completely shut down.
+// Returns true if it should be restarted again.
+func runFlamencoManager() bool {
 	// Load configuration.
 	configService := config.NewService()
 	err := configService.Load()
@@ -106,7 +125,7 @@ func main() {
 			log.Error().Err(err).Msg("could not write configuration file")
 			os.Exit(1)
 		}
-		return
+		return false
 	}
 
 	// TODO: enable TLS via Let's Encrypt.
@@ -149,6 +168,11 @@ func main() {
 		configService.Get().WorkerTimeout,
 		timeService, persist, taskStateMachine, logStorage, webUpdater)
 
+	// The main context determines the lifetime of the application. All
+	// long-running goroutines need to keep an eye on this, and stop their work
+	// once it closes.
+	mainCtx, mainCtxCancel := context.WithCancel(context.Background())
+
 	installSignalHandler(mainCtxCancel)
 
 	// Before doing anything new, clean up in case we made a mess in an earlier run.
@@ -201,8 +225,16 @@ func main() {
 		go openWebbrowser(mainCtx, urls[0])
 	}
 
+	// Allow the Flamenco API itself trigger a shutdown as well.
+	log.Debug().Msg("waiting for a shutdown request from Flamenco")
+	doRestart := flamenco.WaitForShutdown(mainCtx)
+	log.Info().Bool("willRestart", doRestart).Msg("going to shut down the service")
+	mainCtxCancel()
+
 	wg.Wait()
-	log.Info().Msg("shutdown complete")
+	log.Info().Bool("willRestart", doRestart).Msg("Flamenco Manager service shut down")
+
+	return doRestart
 }
 
 func buildFlamencoAPI(
@@ -215,7 +247,7 @@ func buildFlamencoAPI(
 	webUpdater *webupdates.BiDirComms,
 	lastRender *last_rendered.LastRenderedProcessor,
 	localStorage local_storage.StorageInfo,
-) api.ServerInterface {
+) *api_impl.Flamenco {
 	compiler, err := job_compilers.Load(timeService)
 	if err != nil {
 		log.Fatal().Err(err).Msg("error loading job compilers")

internal/manager/api_impl/api_impl.go

@@ -4,6 +4,7 @@ package api_impl
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 import (
+	"context"
 	"fmt"
 	"net/http"
 	"strconv"
@@ -30,6 +31,10 @@ type Flamenco struct {
 	// the same task. It is also used for certain other queries, like
 	// `MayWorkerRun` to prevent similar race conditions.
 	taskSchedulerMutex sync.Mutex
+
+	// done is closed by Flamenco when it wants the application to shut down and
+	// restart itself from scratch.
+	done chan struct{}
 }
 
 var _ api.ServerInterface = (*Flamenco)(nil)
@@ -58,9 +63,29 @@ func NewFlamenco(
 		clock:        ts,
 		lastRender:   lr,
 		localStorage: localStorage,
+
+		done: make(chan struct{}),
 	}
 }
 
+// WaitForShutdown waits until Flamenco wants to shut down the application.
+// Returns `true` when the application should restart.
+// Returns `false` when the context closes.
+func (f *Flamenco) WaitForShutdown(ctx context.Context) bool {
+	select {
+	case <-ctx.Done():
+		return false
+	case <-f.done:
+		return true
+	}
+}
+
+// requestShutdown closes the 'done' channel, signalling to callers of
+// WaitForShutdown() that a shutdown is requested.
+func (f *Flamenco) requestShutdown() {
+	close(f.done)
+}
+
 // sendAPIError wraps sending of an error in the Error format, and
 // handling the failure to marshal that.
 func sendAPIError(e echo.Context, code int, message string, args ...interface{}) error {

internal/manager/api_impl/meta.go

@@ -292,6 +292,10 @@ func (f *Flamenco) SaveWizardConfig(e echo.Context) error {
 	}
 
 	logger.Info().Msg("first-time wizard: updating configuration")
+
+	// Request the shutdown in a goroutine, so that this one can continue sending the response.
+	go f.requestShutdown()
+
 	return e.NoContent(http.StatusNoContent)
 }