config.go

package main

import (
	"fmt"
	"os"
	"strconv"
	"strings"
)

type Config struct {
	GRPCPort      int
	HTTPPort      int
	KafkaBrokers  []string
	KafkaTopic    string
	JaegerEndpoint string
}

func LoadConfig() (*Config, error) {
	grpcPort, err := envInt("GRPC_PORT", 4317)
	if err != nil {
		return nil, fmt.Errorf("config: GRPC_PORT: %w", err)
	}

	httpPort, err := envInt("HTTP_PORT", 8080)
	if err != nil {
		return nil, fmt.Errorf("config: HTTP_PORT: %w", err)
	}

	brokers := strings.Split(envString("KAFKA_BROKERS", "kafka:9092"), ",")

	return &Config{
		GRPCPort:       grpcPort,
		HTTPPort:       httpPort,
		KafkaBrokers:   brokers,
		KafkaTopic:     envString("KAFKA_TOPIC", "otel.traces"),
		JaegerEndpoint: envString("JAEGER_ENDPOINT", "jaeger:4317"),
	}, nil
}

func envString(key, def string) string {
	if v := os.Getenv(key); v != "" {
		return v
	}
	return def
}

func envInt(key string, def int) (int, error) {
	v := os.Getenv(key)
	if v == "" {
		return def, nil
	}
	n, err := strconv.Atoi(v)
	if err != nil {
		return 0, fmt.Errorf("invalid integer %q: %w", v, err)
	}
	return n, nil
}