new method of working with config

internal/config/config.go

@@ -0,0 +1,55 @@
+package config
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/hashicorp/logutils"
+)
+
+type Config struct {
+	// time configuration
+	TimeFormat    string `env:"TIME_FORMAT" default:"2006-01-02 15:04:05"`
+	TimeZoneLocal *time.Location
+	TimeZoneUTC   *time.Location
+
+	// logging
+	LogLevel int `env:"LOG_LEVEL" default:"50"`
+	Log      *logutils.LevelFilter
+
+	// webserver
+	WebServerPort         int    `env:"WEBSERVER_PORT" default:"8080"`
+	WebServerIP           string `env:"WEBSERVER_IP" default:"0.0.0.0"`
+	WebServerReadTimeout  int    `env:"WEBSERVER_READ_TIMEOUT" default:"5"`
+	WebServerWriteTimeout int    `env:"WEBSERVER_WRITE_TIMEOUT" default:"1"`
+	WebServerIdleTimeout  int    `env:"WEBSERVER_IDLE_TIMEOUT" default:"2"`
+}
+
+func NewConfig() (*Config, error) {
+	cfg := &Config{}
+
+	return cfg, nil
+}
+
+func (cfg *Config) Validate() error {
+	checks := []struct {
+		bad    bool
+		errMsg string
+	}{
+		{cfg.TimeFormat == "", "no TimeFormat specified"},
+		{cfg.LogLevel == 0, "no LogLevel specified"},
+		{cfg.WebServerPort == 0, "no WebServer.Port specified"},
+		{cfg.WebServerIP == "", "no WebServer.IP specified"},
+		{cfg.WebServerReadTimeout == 0, "no WebServer.ReadTimeout specified"},
+		{cfg.WebServerWriteTimeout == 0, "no WebServer.WriteTimeout specified"},
+		{cfg.WebServerIdleTimeout == 0, "no WebServer.IdleTimeout specified"},
+	}
+
+	for _, check := range checks {
+		if check.bad {
+			return fmt.Errorf("invalid config: %s", check.errMsg)
+		}
+	}
+
+	return nil
+}