From d7ea0508cf776c5e1c22eaa548f53332670c50b3 Mon Sep 17 00:00:00 2001
From: Mike Bloy <mike@bloy.org>
Date: Sun, 15 Sep 2024 00:51:18 -0500
Subject: [PATCH] move web server to goroutine

---
 cmd/root.go   | 47 ++++++++++++++++++++++++-----------------------
 web/server.go | 31 +++++++++++++++++++------------
 2 files changed, 43 insertions(+), 35 deletions(-)

diff --git a/cmd/root.go b/cmd/root.go
index 3fc47a1..6990600 100644
--- a/cmd/root.go
+++ b/cmd/root.go
@@ -1,13 +1,13 @@
 package cmd
 
 import (
+	"context"
 	"fmt"
 	"log"
 	"log/slog"
-	"math/rand"
 	"os"
-	"strings"
-	"time"
+	"os/signal"
+	"syscall"
 
 	"git.bloy.org/mike/hasshelper/web"
 	"github.com/spf13/cobra"
@@ -22,30 +22,32 @@ var rootCmd = &cobra.Command{
 	Run:   rootCmdRun,
 }
 
-func logLevelVar(str string) slog.Level {
-	levelUpper := strings.ToUpper(str)
-	switch levelUpper {
-	case "DEBUG":
-		return slog.LevelDebug
-	case "INFO":
-		return slog.LevelInfo
-	case "WARN":
-		return slog.LevelWarn
-	case "ERROR":
-		return slog.LevelError
-	default:
-		return slog.LevelInfo
-	}
-}
-
 func rootCmdRun(cmd *cobra.Command, args []string) {
-	logLevel := logLevelVar(viper.GetString("loglevel"))
+	var logLevel slog.Level
+	logLevel.UnmarshalText([]byte(viper.GetString("loglevel")))
 	logger := slog.New(slog.NewTextHandler(os.Stdout,
 		&slog.HandlerOptions{Level: logLevel}))
 	logger.Info("HASSHelper startup", "version", viper.GetString("version"))
 	exitchan := make(chan bool)
-	web.Run(logger, exitchan)
-	<-exitchan // run the main command until one of the goroutines is done
+	signalchan := make(chan os.Signal, 1)
+	done := make(chan bool)
+	signal.Notify(signalchan, syscall.SIGINT, syscall.SIGTERM)
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	web.Run(logger, exitchan, ctx)
+	go func() {
+		select {
+		case <-signalchan:
+			logger.Warn("received interrupt. Exiting")
+			cancel()
+			done <- true
+		case <-exitchan:
+			logger.Error("unexpected exit of component")
+			cancel()
+			done <- true
+		}
+	}()
+	<-done
 }
 
 // Execute will kick off cobra's processing of the root command
@@ -100,5 +102,4 @@ func initConfig() {
 			os.Exit(1)
 		}
 	}
-	rand.Seed(time.Now().UnixNano())
 }
diff --git a/web/server.go b/web/server.go
index 5197e14..bb8151a 100644
--- a/web/server.go
+++ b/web/server.go
@@ -3,10 +3,12 @@ package web
 import (
 	"fmt"
 	"log/slog"
+	"net"
 	"net/http"
 	"time"
 
 	"github.com/spf13/viper"
+	"golang.org/x/net/context"
 )
 
 type configObj struct {
@@ -19,7 +21,7 @@ var config = configObj{}
 
 // Run starts up the webserver part of hasshelper. It writes to exitch if
 // the webserver ends unexpectedly. Config values will be read from viper.
-func Run(rootLogger *slog.Logger, exitch chan bool) {
+func Run(rootLogger *slog.Logger, exitch chan bool, ctx context.Context) {
 	rootLogger = rootLogger.With("component", "web")
 	config.logger = rootLogger
 	config.port = viper.GetInt("webserver_port")
@@ -30,15 +32,21 @@ func Run(rootLogger *slog.Logger, exitch chan bool) {
 	var logger = config.logger
 
 	logger.Info("Webserver startup", "port", config.port, "imageDir", config.imageDir)
-
-	addr := fmt.Sprintf(":%d", config.port)
-
-	if err := http.ListenAndServe(addr, middleware(http.DefaultServeMux)); err != nil {
-		logger.Error("Webserver fatal error", "err", err)
-	} else {
-		logger.Info("Webserver shutting down")
-	}
-	exitch <- true
+	go func() {
+		server := http.Server{
+			Addr:    fmt.Sprintf(":%d", config.port),
+			Handler: middleware(http.DefaultServeMux),
+			BaseContext: func(net.Listener) context.Context {
+				return ctx
+			},
+		}
+		if err := server.ListenAndServe(); err != nil {
+			logger.Error("Webserver fatal error", "err", err)
+		} else {
+			logger.Info("Webserver shutting down")
+		}
+		exitch <- true
+	}()
 }
 
 func middleware(next http.Handler) http.Handler {
@@ -46,8 +54,7 @@ func middleware(next http.Handler) http.Handler {
 		logger := config.logger.
 			WithGroup("request").
 			With("method", r.Method,
-				"url", r.URL,
-				"remote", r.RemoteAddr)
+				"url", r.URL)
 		logger.Info("Starting web request")
 		start := time.Now()
 		next.ServeHTTP(w, r)