Add publig IP getter

Ref #3

This commit uses a GET query to ifconfig.me in order to get the current
public IP. It also modifies the initialization message to send the
current public IP to the Telegram channel instead of a simple message.

tracker/bot/bot.go

@@ -15,7 +15,7 @@ type Notifier struct {
 	cancel       context.CancelFunc
 	tgBot        *bot.ConcreteBot
 	notifChannel int64
-	ipGetter     *ip.IPGetter
+	ipGetter     ip.Getter
 }
 
 func (n *Notifier) SendInitMessage() error {

tracker/ip/ip.go

@@ -7,34 +7,29 @@ import (
 	"io"
 	"net"
 	"net/http"
-	"time"
 )
 
 const ifconfigURL = "https://ifconfig.me"
 const httpMaxRead = 100
-const httpTimeout = 10 * time.Second
 
-type IPGetter struct {
-	httpClt       *http.Client
-	remoteAddress string
-	timeout       time.Duration
+// TODO: use a struct, but a baseHTTPClient inside it to perform unit tests
+type Getter interface {
+	GetCurrentPublicIP(ctx context.Context) (net.IP, error)
 }
 
-func (c *IPGetter) GetCurrentPublicIP(ctx context.Context) (net.IP, error) {
-	reqCtx, cancel := context.WithTimeout(ctx, c.timeout)
-	defer cancel()
+type concreteIPGetter struct {
+}
 
-	req, err := http.NewRequestWithContext(reqCtx, http.MethodGet, c.remoteAddress, nil)
+func (c *concreteIPGetter) GetCurrentPublicIP(ctx context.Context) (net.IP, error) {
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, ifconfigURL, nil)
 	if err != nil {
 		return nil, fmt.Errorf("failed to prepare public IP request: %w", err)
 	}
-	resp, err := c.httpClt.Do(req)
+	resp, err := http.DefaultClient.Do(req)
 	if err != nil {
 		return nil, fmt.Errorf("failed to get current IP from ifconfig: %w", err)
 	}
-	if resp.StatusCode != http.StatusOK {
-		return nil, fmt.Errorf("invalid returncode %d", resp.StatusCode)
-	}
+
 	if resp.ContentLength > httpMaxRead {
 		return nil, fmt.Errorf("response too big: %d/%d", resp.ContentLength, httpMaxRead)
 	}
@@ -52,10 +47,6 @@ func (c *IPGetter) GetCurrentPublicIP(ctx context.Context) (net.IP, error) {
 	return res, nil
 }
 
-func New() *IPGetter {
-	return &IPGetter{
-		httpClt:       http.DefaultClient,
-		remoteAddress: ifconfigURL,
-		timeout:       httpTimeout,
-	}
+func New() *concreteIPGetter {
+	return &concreteIPGetter{}
 }

tracker/ip/ip_test.go

@@ -1,134 +0,0 @@
-package ip
-
-import (
-	"context"
-	"net/http"
-	"net/http/httptest"
-	"strings"
-	"testing"
-	"time"
-)
-
-func TestGetIPOK(t *testing.T) {
-	t.Parallel()
-
-	mockSrv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		w.WriteHeader(http.StatusOK)
-		w.Write([]byte("198.51.100.42"))
-	}))
-	defer mockSrv.Close()
-
-	clt := IPGetter{
-		httpClt:       mockSrv.Client(),
-		remoteAddress: mockSrv.URL,
-		timeout:       1 * time.Second,
-	}
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
-	val, err := clt.GetCurrentPublicIP(ctx)
-	if err != nil {
-		t.Fatalf("Unexpected error %s", err.Error())
-	}
-	if val.String() != "198.51.100.42" {
-		t.Fatalf("Unexpected public IP %v", val)
-	}
-}
-
-func TestGetIPServerErr(t *testing.T) {
-	t.Parallel()
-
-	mockSrv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		w.WriteHeader(http.StatusInternalServerError)
-	}))
-	defer mockSrv.Close()
-
-	clt := IPGetter{
-		httpClt:       mockSrv.Client(),
-		remoteAddress: mockSrv.URL,
-		timeout:       1 * time.Second,
-	}
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
-	_, err := clt.GetCurrentPublicIP(ctx)
-	if err == nil {
-		t.Fatal("Unexpected nil error")
-	} else if err.Error() != "invalid returncode 500" {
-		t.Fatalf("Unexpected error %s", err.Error())
-	}
-}
-
-func TestGetIPUnreachable(t *testing.T) {
-	t.Parallel()
-
-	mockSrv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-	}))
-	mockSrv.Close()
-
-	clt := IPGetter{
-		httpClt:       mockSrv.Client(),
-		remoteAddress: mockSrv.URL,
-		timeout:       1 * time.Second,
-	}
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
-	_, err := clt.GetCurrentPublicIP(ctx)
-	if err == nil {
-		t.Fatal("Unexpected nil error")
-	} else if !strings.Contains(err.Error(), "connect: connection refused") {
-		t.Fatalf("Unexpected error %s", err.Error())
-	}
-}
-
-func TestGetIPInvalidResponse(t *testing.T) {
-	t.Parallel()
-
-	mockSrv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		w.WriteHeader(http.StatusOK)
-		w.Write([]byte("toto"))
-	}))
-	defer mockSrv.Close()
-
-	clt := IPGetter{
-		httpClt:       mockSrv.Client(),
-		remoteAddress: mockSrv.URL,
-		timeout:       1 * time.Second,
-	}
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
-	_, err := clt.GetCurrentPublicIP(ctx)
-	if err == nil {
-		t.Fatal("Unexpected nil error")
-	} else if err.Error() != `got an invalid public IP "toto"` {
-		t.Fatalf("Unexpected error %s", err.Error())
-	}
-}
-
-func TestGetIPTimeout(t *testing.T) {
-	t.Parallel()
-
-	mockSrv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		time.Sleep(100 * time.Millisecond)
-		w.WriteHeader(http.StatusOK)
-		w.Write([]byte("toto"))
-	}))
-	defer mockSrv.Close()
-
-	clt := IPGetter{
-		httpClt:       mockSrv.Client(),
-		remoteAddress: mockSrv.URL,
-		timeout:       1 * time.Millisecond,
-	}
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
-	_, err := clt.GetCurrentPublicIP(ctx)
-	if err == nil {
-		t.Fatal("Unexpected nil error")
-	} else if !strings.Contains(err.Error(), "context deadline exceeded") {
-		t.Fatalf("Unexpected error %s", err.Error())
-	}
-}

tracker/main.go

@@ -9,6 +9,10 @@ import (
 	"git.faercol.me/faercol/public-ip-tracker/tracker/config"
 )
 
+func testMethod(a int) int {
+	return a + 2
+}
+
 type cliArgs struct {
 	configPath string
 }

tracker/main_test.go

@@ -0,0 +1,9 @@
+package main
+
+import "testing"
+
+func TestTestMethod(t *testing.T) {
+	if testMethod(12) != 14 {
+		t.Fatalf("Unexpected result %d", testMethod((12)))
+	}
+}