some doco updates

pkg/utils/ipaddress.go

@@ -0,0 +1,65 @@
+package utils
+
+import (
+	"io"
+	"net"
+	"net/http"
+	"regexp"
+)
+
+// IPVersion specifies the IP version (IPv4 or IPv6).
+type IPVersion int
+
+const (
+	IPv4 IPVersion = 4
+	IPv6 IPVersion = 6
+)
+
+// fetchWebpage fetches the content of a URL and returns it as a string.
+// It uses the specified IP version for the HTTP request.
+func fetchWebpage(url string, version IPVersion) string {
+	client := &http.Client{
+		Transport: &http.Transport{
+			DialContext: (&net.Dialer{}).DialContext,
+			Dial: func(network, addr string) (net.Conn, error) {
+				if version == IPv6 {
+					addr = "[" + addr + "]"
+				}
+				return net.Dial(network, addr)
+			},
+		},
+	}
+
+	resp, err := client.Get(url)
+	if err != nil {
+		return ""
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return ""
+	}
+
+	return string(body)
+}
+
+// extractIPAddress extracts the IP address from the given string.
+func extractIPAddress(input string) string {
+	re := regexp.MustCompile(`(?m)Your IP Address:</strong> ([^<]+)`)
+	matches := re.FindStringSubmatch(input)
+	if len(matches) < 1 {
+		return ""
+	}
+	return matches[0]
+}
+
+// GetPublicIPAddress returns the public IP address of the machine.
+func GetPublicIPAddress() (string, string) {
+	ipv4 := fetchWebpage("https://real-debrid.com/vpn", IPv4)
+	ipv4address := extractIPAddress(ipv4)
+	ipv6 := fetchWebpage("https://real-debrid.com/vpn", IPv6)
+	ipv6address := extractIPAddress(ipv6)
+
+	return ipv4address, ipv6address
+}