Improve error handling in api and modules

api/database.go

@@ -103,6 +103,10 @@ func startDatabaseAPI(w http.ResponseWriter, r *http.Request) {
 }
 
 func (api *DatabaseAPI) handler(context.Context) error {
+	defer func() {
+		_ = api.shutdown(nil)
+	}()
+
 	// 123|get|<key>
 	//    123|ok|<key>|<data>
 	//    123|error|<message>
@@ -206,6 +210,10 @@ func (api *DatabaseAPI) handler(context.Context) error {
 }
 
 func (api *DatabaseAPI) writer(ctx context.Context) error {
+	defer func() {
+		_ = api.shutdown(nil)
+	}()
+
 	var data []byte
 	var err error
 
@@ -214,12 +222,12 @@ func (api *DatabaseAPI) writer(ctx context.Context) error {
 		// prioritize direct writes
 		case data = <-api.sendQueue:
 			if len(data) == 0 {
-				return api.shutdown(nil)
+				return nil
 			}
 		case <-ctx.Done():
-			return api.shutdown(nil)
+			return nil
 		case <-api.shutdownSignal:
-			return api.shutdown(nil)
+			return nil
 		}
 
 		// log.Tracef("api: sending %s", string(*msg))

api/router.go

@@ -258,6 +258,10 @@ func (mh *mainHandler) handle(w http.ResponseWriter, r *http.Request) error {
 	// Format panics in handler.
 	defer func() {
 		if panicValue := recover(); panicValue != nil {
+			// Report failure via module system.
+			me := module.NewPanicError("api request", "custom", panicValue)
+			me.Report()
+			// Respond with a server error.
 			if devMode() {
 				http.Error(
 					lrw,

modules/modules.go

@@ -304,6 +304,9 @@ func (m *Module) stopAllTasks(reports chan *report, stopComplete chan struct{})
 	m.Unlock()
 	m.notifyOfChange()
 
+	// Resolve any errors still on the module.
+	m.Resolve("")
+
 	// send report
 	reports <- &report{
 		module: m,