[#288] Fix possibility of panic during SIGHUP

Signed-off-by: Marina Biryukova <m.biryukova@yadro.com>

CHANGELOG.md

@@ -8,6 +8,7 @@ This document outlines major changes between releases.
 - Fix marshaling errors in `DeleteObjects` method (#222)
 - Fix status code in GET/HEAD delete marker (#226)
 - Fix `NextVersionIDMarker` in `list-object-versions` (#248)
+- Fix possibility of panic during SIGHUP (#288)
 
 ### Added
 - Add new `frostfs.buffer_max_size_for_put` config param and sync TZ hash for PUT operations (#197)

cmd/s3-gw/service.go

@@ -34,6 +34,9 @@ func (ms *Service) ShutDown(ctx context.Context) {
 	ms.log.Info(logs.ShuttingDownService, zap.String("endpoint", ms.Addr))
 	err := ms.Shutdown(ctx)
 	if err != nil {
-		ms.log.Panic(logs.CantShutDownService)
+		ms.log.Error(logs.CantGracefullyShutDownService, zap.Error(err))
+		if err = ms.Close(); err != nil {
+			ms.log.Panic(logs.CantShutDownService, zap.Error(err))
+		}
 	}
 }

internal/logs/logs.go

@@ -12,6 +12,7 @@ const (
 	ServiceCouldntStartOnConfiguredPort                  = "service couldn't start on configured port"                                                         // Warn in ../../cmd/s3-gw/service.go
 	ServiceHasntStartedSinceItsDisabled                  = "service hasn't started since it's disabled"                                                        // Info in ../../cmd/s3-gw/service.go
 	ShuttingDownService                                  = "shutting down service"                                                                             // Info in ../../cmd/s3-gw/service.go
+	CantGracefullyShutDownService                        = "can't gracefully shut down service, force stop"                                                    // Error in ../../cmd/s3-gw/service.go
 	ContainerResolverWillBeDisabled                      = "container resolver will be disabled because of resolvers 'resolver_order' is empty"                // Info in ../../cmd/s3-gw/app.go
 	FailedToInitializeTracing                            = "failed to initialize tracing"                                                                      // Warn in ../../cmd/s3-gw/app.go
 	TracingConfigUpdated                                 = "tracing config updated"                                                                            // Info in ../../cmd/s3-gw/app.go