coller/src/cmd/collerd/main.go

package main

import (
	"flag"
	"log/slog"
	"os"

	"github.com/prometheus/client_golang/prometheus"

	"git.riou.xyz/jriou/coller/internal"
	"git.riou.xyz/jriou/coller/server"
)

var (
	AppName    = "collerd"
	AppVersion string
	GoVersion  string
	GitCommit  string
)

func handleMain() int {

	var err error
	config := server.NewConfig()

	version := flag.Bool("version", false, "Print version and exit")
	quiet := flag.Bool("quiet", false, "Log errors only")
	verbose := flag.Bool("verbose", false, "Print more logs")
	debug := flag.Bool("debug", false, "Print even more logs")
	jsonFormat := flag.Bool("json", false, "Print logs in JSON format")
	configFileName := flag.String("config", "", "Configuration file name")

	flag.Parse()

	if *version {
		internal.ShowVersion(AppName, AppVersion, GitCommit, GoVersion)
		return internal.RC_OK
	}

	var level slog.Level
	if *debug {
		level = slog.LevelDebug
	}
	if *verbose {
		level = slog.LevelInfo
	}
	if *quiet {
		level = slog.LevelError
	}

	var logger *slog.Logger
	if *jsonFormat {
		logger = slog.New(slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{Level: level}))
	} else {
		logger = slog.New(slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{Level: level}))
	}

	if *configFileName != "" {
		err = internal.ReadConfig(*configFileName, config)
		if err != nil {
			return internal.ReturnError(logger, "could not parse configuration file", err)
		}
		logger.Debug("configuration file parsed", slog.Any("file", *configFileName))
	}

	if err = config.Check(); err != nil {
		return internal.ReturnError(logger, "invalid configuration", err)
	}

	db, err := server.NewDatabase(logger, config)
	if err != nil {
		return internal.ReturnError(logger, "could not connect to the database", err)
	}

	srv, err := server.NewServer(logger, db, config, AppVersion)
	if err != nil {
		return internal.ReturnError(logger, "could not create server", err)
	}

	srv.SetEncryptionKeyLength(config.EncryptionKeyLength)

	if config.EnableMetrics {
		reg := prometheus.NewRegistry()
		metrics, err := server.NewMetrics(logger, reg, config, db)
		if err != nil {
			return internal.ReturnError(logger, "could not register metrics", err)
		}
		srv.SetMetrics(metrics)
	}

	err = srv.Start()
	if err != nil {
		return internal.ReturnError(logger, "could not start server", err)
	}

	return internal.RC_OK
}

func main() {
	os.Exit(handleMain())
}