Added icanhazip resolver

main.go

@@ -25,6 +25,8 @@ func getResolver(resolverName string) (PublicIpResolver, string) {
 		return public_resolvers.NewDefaultCloudflareTrace(), public_resolvers.CloudflareTraceTag
 	case public_resolvers.V4IdentMeTag:
 		return public_resolvers.NewV4IdentMeDefault(), public_resolvers.V4IdentMeTag
+	case public_resolvers.IcanhazipTag:
+		return public_resolvers.NewIcanhazipDefault(), public_resolvers.IcanhazipTag
 	case public_resolvers.IfConfigMeTag:
 		fallthrough
 	default:

public_resolvers/icanhazip.go

@@ -0,0 +1,31 @@
+package public_resolvers
+
+import (
+	"net/http"
+	"time"
+)
+
+const (
+	IcanhazipTag = "icanhazip"
+	IcanhazipUrl = "https://v4.icanhazip.com/"
+)
+
+type Icanhazip struct {
+	baseResolver
+}
+
+func NewIcanhazipDefault() *Icanhazip {
+	return NewIcanhazip(&http.Client{
+		Timeout: 10 * time.Second,
+	})
+}
+
+func NewIcanhazip(client Doer) *Icanhazip {
+	return &Icanhazip{
+		baseResolver: baseResolver{
+			client:   client,
+			url:      v4IdentMeUrl,
+			ipParser: defaultIpParser,
+		},
+	}
+}