clear

internal/config/config.go

@@ -1,10 +1,15 @@
 package config
 
 import (
+	"net"
 	"os"
 	"path/filepath"
 )
 
+const (
+	ClientPort = ":8100"
+)
+
 func GetStoryFilepath() string {
 	return getFilepath("STORY_FILENAME", "data/story/story.json")
 }
@@ -13,6 +18,18 @@ func GetDBFilepath() string {
 	return getFilepath("DB_FILENAME", "data/db/store.db")
 }
 
+func GetHost() string {
+	host := os.Getenv("HOST")
+	if host != "" {
+		return host
+	}
+	ips, err := getLocalIPs()
+	if err != nil || len(ips) == 0 {
+		return "127.0.0.1" + ClientPort
+	}
+	return ips[0] + ClientPort
+}
+
 func getFilepath(env string, defaultFilepath string) string {
 	filepath := selectFilepath(env, defaultFilepath)
 	ensureDirExists(filepath)
@@ -34,3 +51,29 @@ func ensureDirExists(filePath string) error {
 	}
 	return os.MkdirAll(dir, 0755)
 }
+
+func getLocalIPs() ([]string, error) {
+	var ips []string
+	addrs, err := net.InterfaceAddrs()
+	if err != nil {
+		return nil, err
+	}
+
+	for _, addr := range addrs {
+		ipNet, ok := addr.(*net.IPNet)
+		if !ok {
+			continue
+		}
+
+		ip := ipNet.IP
+		if ip.IsLoopback() || ip.IsLinkLocalMulticast() || ip.IsLinkLocalUnicast() {
+			continue
+		}
+
+		if ipv4 := ip.To4(); ipv4 != nil {
+			ips = append(ips, ipv4.String())
+		}
+	}
+
+	return ips, nil
+}