Initial commit

backend/internal/config/conf.go

@@ -0,0 +1,81 @@
+package config
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io/ioutil"
+
+	"github.com/ardanlabs/conf/v2"
+	"github.com/ardanlabs/conf/v2/yaml"
+
+	"os"
+)
+
+const (
+	ModeDevelopment = "development"
+	ModeProduction  = "production"
+)
+
+type Config struct {
+	Mode     string      `yaml:"mode" conf:"default:development"` // development or production
+	Web      WebConfig   `yaml:"web"`
+	Database Database    `yaml:"database"`
+	Log      LoggerConf  `yaml:"logger"`
+	Mailer   MailerConf  `yaml:"mailer"`
+	Seed     Seed        `yaml:"seed"`
+	Swagger  SwaggerConf `yaml:"swagger"`
+}
+
+type SwaggerConf struct {
+	Host   string `yaml:"host" conf:"default:localhost:7745"`
+	Scheme string `yaml:"scheme" conf:"default:http"`
+}
+
+type WebConfig struct {
+	Port string `yaml:"port" conf:"default:7745"`
+	Host string `yaml:"host" conf:"default:127.0.0.1"`
+}
+
+// NewConfig parses the CLI/Config file and returns a Config struct. If the file argument is an empty string, the
+// file is not read. If the file is not empty, the file is read and the Config struct is returned.
+func NewConfig(file string) (*Config, error) {
+	var cfg Config
+
+	const prefix = "API"
+
+	help, err := func() (string, error) {
+		if _, err := os.Stat(file); errors.Is(err, os.ErrNotExist) {
+			return conf.Parse(prefix, &cfg)
+		} else {
+			yamlData, err := ioutil.ReadFile(file)
+			if err != nil {
+				return "", err
+			}
+			return conf.Parse(prefix, &cfg, yaml.WithData(yamlData))
+		}
+	}()
+
+	if err != nil {
+		if errors.Is(err, conf.ErrHelpWanted) {
+			fmt.Println(help)
+			os.Exit(0)
+		}
+		return &cfg, fmt.Errorf("parsing config: %w", err)
+	}
+
+	return &cfg, nil
+}
+
+// Print prints the configuration to stdout as a json indented string
+// This is useful for debugging. If the marshaller errors out, it will panic.
+func (c *Config) Print() {
+	res, err := json.MarshalIndent(c, "", "  ")
+
+	if err != nil {
+		panic(err)
+	}
+
+	fmt.Println(string(res))
+
+}