From 2ddf2dadd792fcbb629d49e87c6ef657dcc99bd8 Mon Sep 17 00:00:00 2001
From: Henrik Hautakoski <henrik.hautakoski@gmail.com>
Date: Tue, 15 Aug 2023 09:37:08 +0200
Subject: [PATCH] Adding ip/resolver/basic_http

---
 ip/resolver/basic_http/service.go      | 42 ++++++++++++++++++++
 ip/resolver/basic_http/service_test.go | 53 ++++++++++++++++++++++++++
 2 files changed, 95 insertions(+)
 create mode 100644 ip/resolver/basic_http/service.go
 create mode 100644 ip/resolver/basic_http/service_test.go

diff --git a/ip/resolver/basic_http/service.go b/ip/resolver/basic_http/service.go
new file mode 100644
index 0000000..8999c44
--- /dev/null
+++ b/ip/resolver/basic_http/service.go
@@ -0,0 +1,42 @@
+package basic_http
+
+import (
+	"io"
+	"net"
+	"net/http"
+	"strings"
+)
+
+type Service struct {
+	ServiceName string
+	Url         string
+	Headers     http.Header
+}
+
+func (s Service) Name() string {
+	return s.ServiceName
+}
+
+func (s Service) Lookup() (net.IP, error) {
+	req, err := http.NewRequest("GET", s.Url, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	req.Header = s.Headers
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	// Trim spaces and stuff.
+	ip_str := strings.TrimSpace(string(body))
+
+	return net.ParseIP(ip_str), err
+}
diff --git a/ip/resolver/basic_http/service_test.go b/ip/resolver/basic_http/service_test.go
new file mode 100644
index 0000000..250aaf7
--- /dev/null
+++ b/ip/resolver/basic_http/service_test.go
@@ -0,0 +1,53 @@
+package basic_http
+
+import (
+	"net"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestService_Name(t *testing.T) {
+	s := Service{ServiceName: "my_service"}
+
+	assert.Equal(t, "my_service", s.Name())
+}
+
+func TestService_Lookup(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		_, err := w.Write([]byte("255.240.85.2"))
+		assert.NoError(t, err)
+	}))
+	defer server.Close()
+
+	s := Service{Url: server.URL}
+
+	ip, err := s.Lookup()
+	assert.NoError(t, err)
+
+	assert.Equal(t, net.IPv4(255, 240, 85, 2), ip)
+}
+
+func TestService_Lookup_WithHeaders(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		assert.Equal(t, "application/json", r.Header.Get("Content-Type"))
+
+		_, err := w.Write([]byte("125.74.233.13"))
+		assert.NoError(t, err)
+	}))
+	defer server.Close()
+
+	s := Service{
+		Url: server.URL,
+		Headers: http.Header{
+			"Content-Type": []string{"application/json"},
+		},
+	}
+
+	ip, err := s.Lookup()
+	assert.NoError(t, err)
+
+	assert.Equal(t, net.IPv4(125, 74, 233, 13), ip)
+}