ip/resolver: make Service.Lookup() accept a context

ip/resolver/basic_http/service.go

@@ -1,6 +1,7 @@
 package basic_http
 
 import (
+	"context"
 	"fmt"
 	"io"
 	"net"
@@ -18,8 +19,8 @@ func (s Service) Name() string {
 	return s.ServiceName
 }
 
-func (s Service) Lookup() (net.IP, error) {
+func (s Service) Lookup(ctx context.Context) (net.IP, error) {
-	req, err := http.NewRequest("GET", s.Url, nil)
+	req, err := http.NewRequestWithContext(ctx, "GET", s.Url, nil)
 	if err != nil {
 		return nil, err
 	}

ip/resolver/basic_http/service_test.go

@@ -1,6 +1,7 @@
 package basic_http
 
 import (
+	"context"
 	"net"
 	"net/http"
 	"net/http/httptest"
@@ -24,7 +25,7 @@ func TestService_Lookup(t *testing.T) {
 
 	s := Service{Url: server.URL}
 
-	ip, err := s.Lookup()
+	ip, err := s.Lookup(context.Background())
 	assert.NoError(t, err)
 
 	assert.Equal(t, net.IPv4(255, 240, 85, 2), ip)
@@ -46,7 +47,7 @@ func TestService_Lookup_WithHeaders(t *testing.T) {
 		},
 	}
 
-	ip, err := s.Lookup()
+	ip, err := s.Lookup(context.Background())
 	assert.NoError(t, err)
 
 	assert.Equal(t, net.IPv4(125, 74, 233, 13), ip)
@@ -62,7 +63,7 @@ func TestService_Lookup_HTTPError(t *testing.T) {
 		Url: server.URL,
 	}
 
-	ip, err := s.Lookup()
+	ip, err := s.Lookup(context.Background())
 	assert.EqualError(t, err, "HTTP Response: 404 Not Found")
 	assert.Nil(t, ip)
 }
@@ -78,7 +79,7 @@ func TestService_Lookup_ParseError(t *testing.T) {
 		Url: server.URL,
 	}
 
-	ip, err := s.Lookup()
+	ip, err := s.Lookup(context.Background())
 	assert.EqualError(t, err, "Failed to parse ip: random_string")
 	assert.Nil(t, ip)
 }

ip/resolver/jsonip/service.go

@@ -1,6 +1,7 @@
 package jsonip
 
 import (
+	"context"
 	"encoding/json"
 	"net"
 	"net/http"
@@ -20,8 +21,13 @@ func (s Service) Name() string {
 	return "jsonip"
 }
 
-func (s Service) Lookup() (net.IP, error) {
+func (s Service) Lookup(ctx context.Context) (net.IP, error) {
-	resp, err := http.DefaultClient.Get(s.url)
+	req, err := http.NewRequestWithContext(ctx, "GET", s.url, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	resp, err := http.DefaultClient.Do(req)
 	if err != nil {
 		return nil, err
 	}

ip/resolver/jsonip/service_test.go

@@ -1,6 +1,7 @@
 package jsonip
 
 import (
+	"context"
 	"net"
 	"net/http"
 	"net/http/httptest"
@@ -24,8 +25,21 @@ func TestService_Lookup(t *testing.T) {
 
 	s := Service{url: server.URL}
 
-	ip, err := s.Lookup()
+	ip, err := s.Lookup(context.Background())
 	assert.NoError(t, err)
 
 	assert.Equal(t, net.IPv4(211, 46, 32, 214), ip)
 }
+
+func TestService_Lookup_HTTPError(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(404)
+	}))
+	defer server.Close()
+
+	s := Service{url: server.URL}
+
+	ip, err := s.Lookup(context.Background())
+	assert.EqualError(t, err, "HTTP Response: 404 Not Found")
+	assert.Nil(t, ip)
+}

ip/resolver/mock/service.go

@@ -1,6 +1,9 @@
 package mock
 
-import "net"
+import (
+	"context"
+	"net"
+)
 
 type Service struct {
 	IP    net.IP
@@ -11,6 +14,6 @@ func (s Service) Name() string {
 	return "mock"
 }
 
-func (s Service) Lookup() (net.IP, error) {
+func (s Service) Lookup(ctx context.Context) (net.IP, error) {
 	return s.IP, s.Error
 }

ip/resolver/service.go

@@ -1,7 +1,9 @@
 package lookup
 
 import (
+	"context"
 	"net"
+	"time"
 
 	"dnsupdater/ip"
 )
@@ -9,7 +11,7 @@ import (
 type Service interface {
 	Name() string
 
-	Lookup() (net.IP, error)
+	Lookup(ctx context.Context) (net.IP, error)
 }
 
 const WAN_IFACE = "wan"
@@ -17,7 +19,9 @@ const WAN_IFACE = "wan"
 func LookupWrapper(service Service) ip.NetInterfaceIPResolver {
 	return func(iface_name string) (net.IP, error) {
 		if iface_name == WAN_IFACE {
-			return service.Lookup()
+			ctx, cancel := context.WithTimeout(context.Background(), time.Second*10)
+			defer cancel()
+			return service.Lookup(ctx)
 		}
 		return ip.GetInterfaceIP(iface_name)
 	}