triggerssmith/cmd/serve.go

package cmd

import (
	"fmt"
	"log/slog"
	"net"
	"net/http"
	"os"
	"os/signal"
	"syscall"
	"time"

	application "git.oblat.lv/alex/triggerssmith/internal/app"
	"git.oblat.lv/alex/triggerssmith/internal/config"
	"git.oblat.lv/alex/triggerssmith/internal/vars"
	"github.com/spf13/cobra"
)

var optsServeCmd = struct {
	ConfigPath *string
	Debug      *bool
}{}

// simple middleware for request logging
func loggingMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		start := time.Now()

		slog.Info("HTTP request",
			slog.String("method", r.Method),
			slog.String("path", r.URL.Path),
			slog.String("remote", r.RemoteAddr),
		)

		next.ServeHTTP(w, r)

		slog.Debug("HTTP request finished",
			slog.String("method", r.Method),
			slog.String("path", r.URL.Path),
			slog.Duration("latency", time.Since(start)),
		)
	})
}

func writePID(path string) error {
	pid := os.Getpid()

	f, err := os.OpenFile(path, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0644)
	if err != nil {
		return err
	}
	defer f.Close()

	_, err = fmt.Fprintf(f, "%d\n", pid)
	return err
}

var serveCmd = &cobra.Command{
	Use:   "serve",
	Short: "Start the server",
	Run: func(cmd *cobra.Command, args []string) {
		defer func() {
			if r := recover(); r != nil {
				slog.Error("Application panicked", slog.Any("error", r))
				os.Exit(-1)
			}
		}()
		// configure logger
		if *optsServeCmd.Debug {
			slog.SetDefault(slog.New(slog.NewTextHandler(cmd.OutOrStdout(), &slog.HandlerOptions{Level: slog.LevelDebug, AddSource: true})))
		} else {
			slog.SetDefault(slog.New(slog.NewTextHandler(cmd.OutOrStdout(), &slog.HandlerOptions{Level: slog.LevelInfo})))
		}

		pid := os.Getpid()
		slog.Debug("Starting server", slog.Int("pid", pid))
		if err := writePID(vars.PID_PATH); err != nil {
			panic(err)
		}
		slog.Debug("created pid file", slog.String("path", vars.PID_PATH))
		defer os.Remove(vars.PID_PATH)

		// load config
		slog.Debug("Reading configuration", slog.String("path", *optsServeCmd.ConfigPath))
		cfg, err := config.LoadConfig(*optsServeCmd.ConfigPath)
		if err != nil {
			slog.Error("Failed to load configuration", slog.String("path", *optsServeCmd.ConfigPath), slog.String("error", err.Error()))
			return
		}
		slog.Debug("Configuration loaded", slog.Any("config", cfg))

		// init app
		app, err := application.NewApp()
		if err != application.ErrNilPointerWarn && err != nil {
			slog.Error("Failed to create app instance", slog.String("error", err.Error()))
			return
		}
		app.LoadConfiguration(cfg)

		server := app.Server()
		mux := http.NewServeMux()

		// static files
		staticPath := cfg.Server.StaticFilesPath
		slog.Debug("Setting up static file server", slog.String("path", staticPath))
		fs := http.FileServer(http.Dir(staticPath))
		mux.Handle("/static/", http.StripPrefix("/static/", fs))
		handler := loggingMiddleware(mux)

		server.SetHandler(handler)
		server.Init()

		var addr = net.JoinHostPort(cfg.Server.Addr, fmt.Sprintf("%d", cfg.Server.Port))
		slog.Debug("Binding listener", slog.String("address", addr))
		err = server.Start(addr)
		if err != nil {
			slog.Error("Failed to start server", slog.String("error", err.Error()))
			return
		} else {
			slog.Info("Server started", slog.String("address", net.JoinHostPort(cfg.Server.Addr, fmt.Sprintf("%d", cfg.Server.Port))))
		}

		sigch := make(chan os.Signal, 1)
		signal.Notify(sigch, syscall.SIGHUP, syscall.SIGINT, syscall.SIGTERM)
		for true {
			sig := <-sigch
			slog.Debug("got signal", slog.Any("os.Signal", sig))
			switch sig {
			case syscall.SIGHUP:
				if err := config.ReloadConfig(cfg); err != nil {
					slog.Error("Failed to reload configuration", slog.String("error", err.Error()))
				} else {
					slog.Info("Configuration reloaded")
					var addr = net.JoinHostPort(cfg.Server.Addr, fmt.Sprintf("%d", cfg.Server.Port))
					slog.Debug("New configuration", slog.Any("config", cfg))
					err = server.Reload(addr)
					if err != nil {
						slog.Error("Failed to restart server with new configuration", slog.String("error", err.Error()))
					}
				}
			case syscall.SIGINT:
				slog.Info("Stopping server by SIGINT")
				err := server.Stop()
				if err != nil {
					slog.Error("Failed to stop server", slog.String("err", err.Error()))
					os.Exit(1)
				}
				os.Remove(vars.PID_PATH)
				return
			case syscall.SIGTERM:
				slog.Info("Stopping server by SIGTERM")
				err := server.Stop()
				if err != nil {
					slog.Error("Failed to stop server", slog.String("err", err.Error()))
					os.Exit(1)
				}
				os.Remove(vars.PID_PATH)
				return
			}
		}
	},
}

func init() {
	optsServeCmd.Debug = serveCmd.Flags().BoolP("debug", "d", false, "Enable debug logs")
	optsServeCmd.ConfigPath = serveCmd.Flags().StringP("config", "c", "config.yaml", "Path to configuration file")
	rootCmd.AddCommand(serveCmd)
}