Avoid fission installation failure due to analytics connection error (#2457)

pkg/tracker/tracker.go

@@ -19,6 +19,7 @@ import (
 	"bytes"
 	"context"
 	"errors"
+	"fmt"
 	"net/http"
 	"net/url"
 	"os"
@@ -27,16 +28,17 @@ import (
 	uuid "github.com/satori/go.uuid"
 )
 
-const HTTP_TIMEOUT = 5 * time.Second
-const GA_API_URL = "https://www.google-analytics.com/collect"
-const GA_TRACKING_ID = "GA_TRACKING_ID"
-
-var Tracker *tracker
+const (
+	HTTP_TIMEOUT   time.Duration = 5 * time.Second
+	GA_TRACKING_ID string        = "GA_TRACKING_ID"
+	GA_API_URL     string        = "GA_API_URL"
+)
 
 type (
-	tracker struct {
+	Tracker struct {
 		gaPropertyID string
 		cid          string
+		gaAPIURL     string
 	}
 	Event struct {
 		Category string
@@ -46,19 +48,31 @@ type (
 	}
 )
 
-func init() {
+func NewTracker() (*Tracker, error) {
 	id, err := uuid.NewV4()
 	if err != nil {
-		panic(err)
+		return nil, fmt.Errorf("tracker.NewTracker: error generating UUID: %w", err)
 	}
-	Tracker = &tracker{gaPropertyID: os.Getenv(GA_TRACKING_ID), cid: id.String()}
+
+	gaTrackingID := os.Getenv(GA_TRACKING_ID)
+	if gaTrackingID == "" {
+		return nil, errors.New("tracker.NewTracker: GA_TRACKING_ID env not set")
+	}
+
+	gaAPIURL := os.Getenv(GA_API_URL)
+	if gaAPIURL == "" {
+		gaAPIURL = "https://www.google-analytics.com/collect"
+	}
+
+	tracker := &Tracker{
+		gaPropertyID: gaTrackingID,
+		cid:          id.String(),
+		gaAPIURL:     gaAPIURL,
+	}
+	return tracker, nil
 }
 
-func (t *tracker) SendEvent(ctx context.Context, e Event) error {
-	if t.gaPropertyID == "" {
-		return errors.New("tracker.SendEvent: GA_TRACKING_ID env not set")
-	}
-
+func (t *Tracker) SendEvent(ctx context.Context, e Event) error {
 	if e.Action == "" || e.Category == "" {
 		return errors.New("tracker.SendEvent: category and action are required")
 	}
@@ -81,7 +95,7 @@ func (t *tracker) SendEvent(ctx context.Context, e Event) error {
 	}
 
 	buf := bytes.NewBufferString(v.Encode())
-	req, err := http.NewRequestWithContext(ctx, "POST", GA_API_URL, buf)
+	req, err := http.NewRequestWithContext(ctx, "POST", t.gaAPIURL, buf)
 	req.Header.Add("Content-Type", "application/x-www-form-urlencoded")
 	req.Header.Add("User-Agent", "ga-tracker/1.0")
 	if err != nil {

pkg/tracker/tracker_test.go

@@ -0,0 +1,127 @@
+package tracker
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"log"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestTracker(t *testing.T) {
+	t.Run("NewTracker", func(test *testing.T) {
+		for _, test := range []struct {
+			name     string
+			gaAPIURl string
+			expected error
+		}{
+			{
+				name:     "GA Tracking ID should not be empty",
+				gaAPIURl: "",
+				expected: errors.New("tracker.NewTracker: GA_TRACKING_ID env not set"),
+			},
+			{
+				name:     "Tracker should initialize properly",
+				gaAPIURl: "/",
+				expected: nil,
+			},
+		} {
+			t.Run(test.name, func(testing *testing.T) {
+				if test.expected == nil {
+					os.Setenv(GA_TRACKING_ID, "UA-000000-2")
+					t, err := NewTracker()
+					assert.Nil(testing, err)
+					assert.NotNil(testing, t)
+				} else {
+					t, err := NewTracker()
+					assert.Nil(testing, t)
+					assert.NotNil(testing, err)
+					assert.Equal(testing, err.Error(), test.expected.Error())
+				}
+			})
+		}
+	})
+
+	t.Run("SendEvent", func(test *testing.T) {
+
+		os.Setenv(GA_TRACKING_ID, "UA-000000-2")
+		tr, err := NewTracker()
+		if err != nil {
+			log.Fatal(err)
+		}
+		for _, test := range []struct {
+			name     string
+			request  *Event
+			expected error
+			status   int
+		}{
+			{
+				name: "category and action should not be empty",
+				request: &Event{
+					Category: "",
+					Action:   "",
+					Label:    "play",
+					Value:    "value",
+				},
+				expected: errors.New("tracker.SendEvent: category and action are required"),
+				status:   http.StatusInternalServerError,
+			},
+			{
+				name: "Google Analytics response should not be OK",
+				request: &Event{
+					Category: "UI_action",
+					Action:   "button_press",
+					Label:    "play",
+					Value:    "value",
+				},
+
+				expected: errors.New("tracker.SendEvent: analytics response status not ok"),
+				status:   http.StatusInternalServerError,
+			},
+			{
+				name: "Google Analytics response should be OK",
+				request: &Event{
+					Category: "UI_action",
+					Action:   "button_press",
+					Label:    "play",
+					Value:    "value",
+				},
+
+				expected: nil,
+				status:   http.StatusOK,
+			},
+		} {
+			t.Run(test.name, func(testing *testing.T) {
+				server := MockHTTPServer(test.status, "")
+				defer server.Close()
+				tr.gaAPIURL = server.URL
+
+				t := tr.SendEvent(context.Background(), *test.request)
+				if test.status == http.StatusOK {
+					assert.Nil(testing, t, test.expected)
+				} else {
+					assert.NotNil(testing, t)
+					assert.Equal(testing, t.Error(), test.expected.Error())
+				}
+
+			})
+		}
+	})
+}
+
+func MockHTTPServer(status int, encodeValue interface{}) *httptest.Server {
+	f := func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(status)
+		w.Header().Set("Content-Type", "application/json")
+		err := json.NewEncoder(w).Encode(encodeValue)
+		if err != nil {
+			log.Fatal(err)
+		}
+	}
+	return httptest.NewServer(http.HandlerFunc(f))
+}