first version

config/config.go

@@ -0,0 +1,65 @@
+package config
+
+import (
+	"errors"
+
+	"github.com/go-playground/validator"
+	"github.com/imdario/mergo"
+	confLoader "github.com/otakukaze/config-loader"
+)
+
+type Config struct {
+	Server Server `yaml:"server"`
+}
+
+type Server struct {
+	Port   int    `yaml:"port" env:"SERVER_PORT" default:"10230" validate:"gte=1,lte=65535"`
+	Secret string `yaml:"secret" env:"SERVER_SECRET" default:"lawsnote-rpi" validate:"required,min=1"`
+
+	RelayPin int `yaml:"relay_pin" env:"SERVER_RELAY_PIN" validate:"required,gte=1,lte=255"`
+}
+
+func Load(cfgPath ...string) (*Config, error) {
+	cfg := &Config{}
+
+	// load config from env and default value
+	if err := confLoader.Load(cfg, &confLoader.LoadOptions{FromEnv: true}); err != nil {
+		return nil, err
+	}
+
+	validate := validator.New()
+	if len(cfgPath) > 0 {
+
+		for _, v := range cfgPath {
+			fileOpts := &confLoader.ConfigFile{Type: confLoader.ConfigFileTypeYAML, Path: v}
+			loadOpts := &confLoader.LoadOptions{ConfigFile: fileOpts, FromEnv: false}
+
+			c := &Config{}
+
+			if err := confLoader.Load(c, loadOpts); err != nil {
+				return nil, err
+			}
+
+			// validate struct fields
+			if err := validate.Struct(c); err != nil {
+				return nil, err
+			}
+
+			// merge new config to prev config withOverride
+			if err := mergo.Merge(&cfg, c, mergo.WithOverride); err != nil {
+				return nil, err
+			}
+		}
+
+	}
+
+	if cfg.Server.RelayPin < 1 || cfg.Server.RelayPin > 255 {
+		return nil, errors.New("gpio pin range wrong (1 <= x <= 255)")
+	}
+
+	if cfg.Server.Secret == "" {
+		return nil, errors.New("secret empty")
+	}
+
+	return cfg, nil
+}