初始版本

envx/envx.go

@@ -0,0 +1,128 @@
+package envx
+
+import (
+	"net"
+	"os"
+	"strconv"
+	"strings"
+)
+
+func String(key, fallback string) string {
+	if v := os.Getenv(key); v != "" {
+		return v
+	}
+	return fallback
+}
+
+func Int(key string, fallback int) int {
+	if v := os.Getenv(key); v != "" {
+		if i, err := strconv.Atoi(v); err == nil {
+			return i
+		}
+	}
+	return fallback
+}
+
+func LocalIP() string {
+	for _, key := range []string{"nacos_bindIp", "NACOS_BIND_IP", "LOCAL_IP", "BIND_IP"} {
+		if ip := validIPv4(os.Getenv(key)); ip != "" {
+			return ip
+		}
+	}
+	if ip := hostnameIP(); ip != "" {
+		return ip
+	}
+	if ip := interfaceIP(); ip != "" {
+		return ip
+	}
+	if ip := outboundIP(); ip != "" {
+		return ip
+	}
+	return "127.0.0.1"
+}
+
+func hostnameIP() string {
+	hostname, err := os.Hostname()
+	if err != nil || hostname == "" {
+		return ""
+	}
+	addrs, err := net.LookupIP(hostname)
+	if err != nil {
+		return ""
+	}
+	for _, addr := range addrs {
+		if ip := validIPv4(addr.String()); ip != "" {
+			return ip
+		}
+	}
+	return ""
+}
+
+func interfaceIP() string {
+	ifaces, err := net.Interfaces()
+	if err != nil {
+		return ""
+	}
+	bestIP := ""
+	bestScore := -1
+	for _, iface := range ifaces {
+		if iface.Flags&net.FlagUp == 0 || iface.Flags&net.FlagLoopback != 0 {
+			continue
+		}
+		addrs, err := iface.Addrs()
+		if err != nil {
+			continue
+		}
+		for _, addr := range addrs {
+			ipNet, ok := addr.(*net.IPNet)
+			if !ok {
+				continue
+			}
+			ip := validIPv4(ipNet.IP.String())
+			if ip == "" {
+				continue
+			}
+			score := interfaceScore(iface.Name)
+			if score > bestScore {
+				bestIP = ip
+				bestScore = score
+			}
+		}
+	}
+	return bestIP
+}
+
+func interfaceScore(name string) int {
+	name = strings.ToLower(name)
+	switch {
+	case name == "eth0":
+		return 100
+	case strings.HasPrefix(name, "eth"):
+		return 90
+	case strings.HasPrefix(name, "en"), strings.HasPrefix(name, "wl"):
+		return 80
+	case strings.Contains(name, "docker"), strings.HasPrefix(name, "br-"), strings.HasPrefix(name, "veth"):
+		return 10
+	default:
+		return 50
+	}
+}
+
+func outboundIP() string {
+	conn, err := net.Dial("udp", "8.8.8.8:80")
+	if err == nil {
+		defer conn.Close()
+		if addr, ok := conn.LocalAddr().(*net.UDPAddr); ok {
+			return validIPv4(addr.IP.String())
+		}
+	}
+	return ""
+}
+
+func validIPv4(value string) string {
+	ip := net.ParseIP(strings.TrimSpace(value)).To4()
+	if ip == nil || ip.IsLoopback() || ip.IsUnspecified() || ip.IsLinkLocalUnicast() {
+		return ""
+	}
+	return ip.String()
+}