Add 1.1.1.1 resolver

public_resolvers/cloudflare_trace.go

@@ -0,0 +1,49 @@
+package public_resolvers
+
+import (
+	"io"
+	"net/http"
+	"strings"
+	"time"
+)
+
+const (
+	CloudflareTraceTag = "1.1.1.1"
+	CloudflareTraceUrl = "https://1.1.1.1/cdn-cgi/trace"
+
+	ipPrefix = "ip="
+)
+
+type CloudflareTrace struct {
+	baseResolver
+}
+
+func NewDefaultCloudflareTrace() *CloudflareTrace {
+	return NewCloudflareTrace(&http.Client{
+		Timeout: 10 * time.Second,
+	})
+}
+
+func cloudflareTraceResponseParser(reader io.Reader) (string, error) {
+	data, err := io.ReadAll(reader)
+	if err != nil {
+		return "", err
+	}
+
+	for _, row := range strings.Split(string(data), "\n") {
+		if strings.Index(row, ipPrefix) == 0 {
+			return strings.TrimSpace(strings.ReplaceAll(row, ipPrefix, "")), nil
+		}
+	}
+	return "", NoIPInResponseError
+}
+
+func NewCloudflareTrace(client Doer) *CloudflareTrace {
+	return &CloudflareTrace{
+		baseResolver: baseResolver{
+			client:   client,
+			url:      CloudflareTraceUrl,
+			ipParser: cloudflareTraceResponseParser,
+		},
+	}
+}