linstrom/config/config.go

// Copyright (c) 2024 mStar
//
// Licensed under the EUPL, Version 1.2
//
// You may not use this work except in compliance with the Licence.
// You should have received a copy of the Licence along with this work. If not, see:
// <https://joinup.ec.europa.eu/collection/eupl/eupl-text-eupl-12>.
// See the Licence for the specific language governing permissions and limitations under the Licence.
//

package config

import (
	"flag"
	"os"

	"github.com/BurntSushi/toml"
	"github.com/joho/godotenv"
	"github.com/kelseyhightower/envconfig"
	log "github.com/sirupsen/logrus"
)

type CLIArguments struct {
	// Path to a config file
	ConfigFile string
	// Path to a postgres database
	// Nil if not provided
	DbPath *string
}

type Config struct {
	General struct {
		// Path to the postgres db
		DbPath string `envconfig:"DATABASE_PATH" toml:"database_path"`
		// Whether the server should handle ssl itself
		HandleSSL bool `envconfig:"HANDLE_SSL" toml:"handle_ssl"`
		// Whether to enable the builtin frontend
		EnableUI bool   `envconfig:"ENABLE_UI" toml:"enable_ui"`
		Domain   string `envconfig:"DOMAIN" toml:"domain"`
	}
}

// Reads arguments passed to the application
func ReadCLIArguments() CLIArguments {
	configFlag := flag.String("config", "config.toml", "Path to a config file")
	dbFlag := flag.String("db", "", "Path to a postgres database")

	flag.Parse()

	var dbString *string
	if *dbFlag != "" {
		dbString = dbFlag
	}

	return CLIArguments{
		ConfigFile: *configFlag,
		DbPath:     dbString,
	}
}

// Read a config from the given CLI arguments as well as the config file specified in the cli args (default is config.toml)
func ReadConfig(cliArgs *CLIArguments) Config {
	file, err := os.Open(cliArgs.ConfigFile)
	if err != nil {
		log.Fatalf("Failed to open file %s with error %v. Does it exist?\n", cliArgs.ConfigFile, err)
	}
	defer file.Close()

	var cfg Config

	decoder := toml.NewDecoder(file)
	_, err = decoder.Decode(&cfg)
	if err != nil {
		log.Fatalf("Failed to parse config file %s with error %v\n", cliArgs.ConfigFile, err)
	}
	godotenv.Load()
	err = envconfig.Process("", &cfg)
	if err != nil {
		log.Fatalf("Failed to overwrite config from env. Error %v\n", err)
	}

	if cliArgs.DbPath != nil && *cliArgs.DbPath != "" {
		cfg.General.DbPath = *cliArgs.DbPath
	}

	return cfg
}