refactor: addition of wait groups to ensure order of shutdown and other minor edits from reviews

Author: dimakis

cmd/kar-controllers/app/generic-server.go

@@ -103,7 +103,7 @@ func (s *Server) Shutdown() error {
 	if err := s.httpServer.Shutdown(shutdownCtx); err != nil {
 		return fmt.Errorf("failed to shutdown server gracefully: %v", err)
 	}
-	return s.httpServer.Shutdown(shutdownCtx)
+	return nil
 }
 
 // newListener creates a new TCP listener bound to the given address.

cmd/kar-controllers/app/server.go

@@ -5,7 +5,7 @@ Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at
 
-    http://www.apache.org/licenses/LICENSE-2.0
+	http://www.apache.org/licenses/LICENSE-2.0
 
 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
@@ -21,6 +21,7 @@ import (
 	"context"
 	"fmt"
 	"net/http"
+	"sync"
 
 	"golang.org/x/sync/errgroup"
 	"k8s.io/client-go/rest"
@@ -79,8 +80,22 @@ func Run(ctx context.Context, opt *options.ServerOption) error {
 		return err
 	}
 
-	// Start the job controller
-	go jobctrl.Run(ctx.Done())
+	// Create the job controller
+	jobctrl := queuejob.NewJobController(config, opt)
+	if jobctrl == nil {
+		return fmt.Errorf("failed to create a job controller")
+	}
+
+	// Run the job controller in a goroutine and wait for it to exit
+	wg := sync.WaitGroup{}
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		jobctrl.Run(ctx.Done())
+	}()
+
+	wg.Wait()
+
 
 	return nil
 }

cmd/kar-controllers/main.go

@@ -43,6 +43,4 @@ func main() {
 		os.Exit(1)
 	}
 
-	fmt.Println("Shutting down gracefully")
-	
 }