From 0232a5c4f4f878f9d99c0bc069ab88f33d33d98d Mon Sep 17 00:00:00 2001
From: Samuel Lorch <sam@soontm.de>
Date: Thu, 2 Mar 2023 23:00:22 +0100
Subject: [PATCH] add -apply flag, add webserver

---
 api/apply.go         | 23 +++++++++++++++++++++
 api/main.go          | 48 +++++++++++++++++++++++++++++++++++---------
 pkg/server/server.go | 32 +++++++++++++++++++++++++++++
 3 files changed, 93 insertions(+), 10 deletions(-)
 create mode 100644 api/apply.go
 create mode 100644 pkg/server/server.go

diff --git a/api/apply.go b/api/apply.go
new file mode 100644
index 0000000..4d1ede7
--- /dev/null
+++ b/api/apply.go
@@ -0,0 +1,23 @@
+package main
+
+import (
+	"fmt"
+
+	"golang.org/x/exp/slog"
+	"nfsense.net/nfsense/pkg/definitions"
+	"nfsense.net/nfsense/pkg/nftables"
+)
+
+func apply(conf *definitions.Config) error {
+	fileContent, err := nftables.GenerateNfTablesFile(*conf)
+	if err != nil {
+		return fmt.Errorf("Generating nftables file %w", err)
+	}
+
+	err = nftables.ApplyNfTablesFile(fileContent)
+	if err != nil {
+		return fmt.Errorf("Applying nftables %w", err)
+	}
+	slog.Info("Wrote nftables File!")
+	return nil
+}
diff --git a/api/main.go b/api/main.go
index b0b4b88..2bda165 100644
--- a/api/main.go
+++ b/api/main.go
@@ -1,29 +1,57 @@
 package main
 
 import (
+	"context"
+	"flag"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
 	"golang.org/x/exp/slog"
-	"nfsense.net/nfsense/pkg/nftables"
+	"nfsense.net/nfsense/pkg/server"
 )
 
 func main() {
+	applyPtr := flag.Bool("apply", false, "apply config and stop")
+	flag.Parse()
+
 	slog.Info("Starting...")
+
 	conf, err := LoadConfiguration("config.json")
 	if err != nil {
 		slog.Error("Loading Config", err)
 		return
 	}
+
 	slog.Info("Config Loaded", "config", conf)
 
-	fileContent, err := nftables.GenerateNfTablesFile(*conf)
-	if err != nil {
-		slog.Error("Generating nftables file", err)
+	if *applyPtr {
+		slog.Info("Applying Config...")
+		err := apply(conf)
+		if err != nil {
+			slog.Error("Applying Config", err)
+			return
+		}
+		slog.Info("Config Applied, Exiting...")
 		return
 	}
 
-	err = nftables.ApplyNfTablesFile(fileContent)
-	if err != nil {
-		slog.Error("Applying nftables", err)
-		return
-	}
-	slog.Info("Wrote nftables File!")
+	slog.Info("Starting Webserver...")
+	server.StartWebserver(conf)
+
+	slog.Info("Ready")
+
+	// Handle Exit Signal
+	sigChan := make(chan os.Signal, 1)
+	signal.Notify(sigChan, syscall.SIGINT, syscall.SIGTERM)
+	<-sigChan
+	slog.Info("Got Signal, Exiting...")
+
+	shutdownCtx, shutdownRelease := context.WithTimeout(context.Background(), 10*time.Second)
+	defer shutdownRelease()
+
+	server.ShutdownWebserver(shutdownCtx)
+
+	slog.Info("Done")
 }
diff --git a/pkg/server/server.go b/pkg/server/server.go
new file mode 100644
index 0000000..79ac5ec
--- /dev/null
+++ b/pkg/server/server.go
@@ -0,0 +1,32 @@
+package server
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net/http"
+
+	"golang.org/x/exp/slog"
+
+	"nfsense.net/nfsense/pkg/definitions"
+)
+
+var server http.Server
+
+func StartWebserver(conf *definitions.Config) {
+	server.Addr = ":8080"
+	go func() {
+		if err := server.ListenAndServe(); !errors.Is(err, http.ErrServerClosed) {
+			slog.Error("Webserver error", err)
+		}
+		slog.Info("Webserver Stopped")
+	}()
+}
+
+func ShutdownWebserver(ctx context.Context) error {
+	err := server.Shutdown(ctx)
+	if err != nil {
+		return fmt.Errorf("Shutting down: %w", err)
+	}
+	return nil
+}