byom-core-gateway/config/config.go

package config

import (
	"fmt"
	"os"

	"gopkg.in/yaml.v3"
)

type Config struct {
	Server    ServerConfig   `yaml:"server"`
	Database  DatabaseConfig `yaml:"database"`
	BasicAuth BasicAuth      `yaml:"basic_auth"`
	Homepage  string         `yaml:"homepage"`
}

func (c *Config) UnmarshalYAML(unmarshal func(interface{}) error) error {
	type rawConfig Config
	raw := rawConfig{
		Server:   ServerConfig{},
		Database: DatabaseConfig{},
	}

	if err := unmarshal(&raw); err != nil {
		return err
	}

	*c = Config(raw)
	return nil
}

type ServerConfig struct {
	ListeningPort string    `yaml:"port"`
	TlsConfig     TlsConfig `yaml:"tls"`
}

func (c *ServerConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
	type rawServerConfig ServerConfig
	raw := rawServerConfig{
		TlsConfig: TlsConfig{},
	}

	if err := unmarshal(&raw); err != nil {
		return err
	}

	*c = ServerConfig(raw)
	return nil
}

type DatabaseConfig struct {
	File            string   `yaml:"file"`
	LogMode         bool     `yaml:"log_mode"`
	MaxOpenConns    int      `yaml:"max_open_conns"`
	MaxIdleConns    int      `yaml:"max_idle_conns"`
	ConnMaxLifetime int      `yaml:"conn_max_lifetime"`
	Pragma          []string `yaml:"pragma"`
}

func (c *DatabaseConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
	type rawDatabaseConfig DatabaseConfig
	raw := rawDatabaseConfig{}

	if err := unmarshal(&raw); err != nil {
		return err
	}

	if raw.File == "" {
		return fmt.Errorf("database file not provided")
	}

	*c = DatabaseConfig(raw)
	return nil
}

type TlsConfig struct {
	Enabled  bool   `yaml:"enabled"`
	CertFile string `yaml:"cert"`
	KeyFile  string `yaml:"key"`
}

func (c *TlsConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
	type rawTlsConfig TlsConfig
	raw := rawTlsConfig{
		Enabled: false,
	}

	if err := unmarshal(&raw); err != nil {
		return err
	}

	if raw.Enabled && (raw.CertFile == "" || raw.KeyFile == "") {
		return fmt.Errorf("tls enabled but cert or key not provided")
	}

	*c = TlsConfig(raw)
	return nil
}

type BasicAuth struct {
	Username string `yaml:"username"`
	Password string `yaml:"password"`
}

func (c *BasicAuth) UnmarshalYAML(unmarshal func(interface{}) error) error {
	type rawBasicAuth BasicAuth
	raw := rawBasicAuth{}

	if err := unmarshal(&raw); err != nil {
		return err
	}

	if raw.Username == "" || raw.Password == "" {
		return fmt.Errorf("username or password not provided")
	}

	*c = BasicAuth(raw)
	return nil
}

func ReadConfig(cfgPath string) (*Config, error) {
	cfg, err := os.ReadFile(cfgPath)
	if err != nil {
		return nil, err
	}

	var config Config
	if err := yaml.Unmarshal(cfg, &config); err != nil {
		return nil, err
	}

	fmt.Println(config)

	return &config, nil
}