Initial commit

internal/util/net/net.go

@@ -0,0 +1,25 @@
+package net
+
+import (
+	"net"
+
+	"github.com/pkg/errors"
+)
+
+// DetectHostIPv4 attempts to determine the host IPv4 address by finding the
+// first non-loopback device with an assigned IPv4 address.
+func DetectHostIPv4() (string, error) {
+	addrs, err := net.InterfaceAddrs()
+	if err != nil {
+		return "", errors.WithStack(err)
+	}
+	for _, a := range addrs {
+		if ipnet, ok := a.(*net.IPNet); ok && !ipnet.IP.IsLoopback() {
+			if ipnet.IP.To4() == nil {
+				continue
+			}
+			return ipnet.IP.String(), nil
+		}
+	}
+	return "", errors.New("cannot detect host IPv4 address")
+}