Simple Go HTTP server with graceful signal handling

Signed-off-by: Mel <einebeere@gmail.com>

1 files changed, 56 insertions, 2 deletions

diff --git a/application/cmd/specimen/main.go b/application/cmd/specimen/main.go
index 8522b03..cf7ff36 100644
--- a/application/cmd/specimen/main.go
+++ b/application/cmd/specimen/main.go
@@ -1,10 +1,64 @@
 package main
 
 import (
-	"fmt"
+	"context"
+	"log/slog"
+	"os"
+	"os/signal"
+	"time"
+
 	"git.rnrd.eu/specimen/pkg/specimen"
+	"git.rnrd.eu/specimen/pkg/util"
 )
 
+const version = "3.3.3"
+
 func main() {
-	fmt.Println(specimen.ASimpleMessage())
+	ctx := context.Background()
+	logger := createLogger()
+
+	if err := start(ctx, logger); err != nil {
+		logger.Error("failed to start the specimen application :(", util.SlogErr(err))
+		os.Exit(1)
+	}
+}
+
+func start(ctx context.Context, logger *slog.Logger) error {
+	// listen for SIGINT (or others on other systems, but who cares about those.. :3)
+	ctx, cancel := signal.NotifyContext(ctx, os.Interrupt)
+	defer cancel()
+
+	logger.Info("starting the specimen application!", slog.String("version", version))
+
+	// start the specimen server!
+	server := specimen.NewServer(logger)
+	go server.Start(ctx)
+
+	// listen for signals to gracefully shutdown the server
+	return listenForSignals(ctx, server, logger)
+}
+
+func listenForSignals(ctx context.Context, server *specimen.Server, logger *slog.Logger) error {
+	// waiting for the global context to be done (happens on SIGINT)
+	<-ctx.Done()
+	logger.Info("received signal to shutdown the server, trying to gracefully shutdown...")
+
+	shutdownCtx, cancelShutdown := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancelShutdown()
+
+	if err := server.Shutdown(shutdownCtx); err != nil {
+		logger.Error("failed to gracefully shutdown the server :( forcing it.", util.SlogErr(err))
+		os.Exit(1)
+	}
+
+	logger.Info("specimen has been gracefully shutdown! goodbye!")
+	return nil
+}
+
+func createLogger() *slog.Logger {
+	handlerOptions := slog.HandlerOptions{
+		Level: slog.LevelDebug,
+	}
+	consoleHandler := slog.NewTextHandler(os.Stderr, &handlerOptions)
+	return slog.New(consoleHandler)
 }