[hw-1] implement cart service

cart/internal/infra/config/config.go

@@ -0,0 +1,64 @@
+package config
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"gopkg.in/yaml.v3"
+)
+
+type Config struct {
+	Service struct {
+		Host     string `yaml:"host"`
+		Port     string `yaml:"port"`
+		LogLevel string `yaml:"log_level"`
+		Workers  int    `yaml:"workers"`
+	} `yaml:"service"`
+
+	Jaeger struct {
+		Host string `yaml:"host"`
+		Port string `yaml:"port"`
+	} `yaml:"jaeger"`
+
+	ProductService struct {
+		Host  string `yaml:"host"`
+		Port  string `yaml:"port"`
+		Token string `yaml:"token"`
+		Limit int    `yaml:"limit"`
+		Burst int    `yaml:"burst"`
+	} `yaml:"product_service"`
+
+	LomsService struct {
+		Host string `yaml:"host"`
+		Port string `yaml:"port"`
+	} `yaml:"loms_service"`
+}
+
+func LoadConfig(filename string) (*Config, error) {
+	workDir, err := os.Getwd()
+	if err != nil {
+		return nil, err
+	}
+	cfgRoot := filepath.Join(workDir, "configs")
+	absCfgRoot, _ := filepath.Abs(cfgRoot)
+
+	filePath := filepath.Join(absCfgRoot, filepath.Clean(filename))
+	if !strings.HasPrefix(filePath, absCfgRoot) {
+		return nil, fmt.Errorf("invalid path")
+	}
+
+	f, err := os.Open(filename)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	config := &Config{}
+	if err := yaml.NewDecoder(f).Decode(config); err != nil {
+		return nil, err
+	}
+
+	return config, nil
+}