Added support for custom http client for transmitter

.gitignore

@@ -6,6 +6,7 @@
 # Folders
 _obj
 _test
+.idea
 
 # Architecture specific extensions/prefixes
 *.[568vq]

appinsights/configuration.go

@@ -1,6 +1,7 @@
 package appinsights
 
 import (
+	"net/http"
 	"os"
 	"runtime"
 	"time"
@@ -21,6 +22,9 @@ type TelemetryConfiguration struct {
 
 	// Maximum time to wait before sending a batch of telemetry.
 	MaxBatchInterval time.Duration
+
+	// Customized http client if desired (will use http.DefaultClient otherwise)
+	Client *http.Client
 }
 
 // Creates a new TelemetryConfiguration object with the specified

appinsights/configuration_test.go

@@ -15,4 +15,8 @@ func TestTelemetryConfiguration(t *testing.T) {
 	if config.EndpointUrl != defaultEndpoint {
 		t.Errorf("EndpointUrl is %s, want %s", config.EndpointUrl, defaultEndpoint)
 	}
+
+	if config.Client != nil {
+		t.Errorf("Client is not nil, want nil")
+	}
 }

appinsights/inmemorychannel.go

@@ -53,7 +53,7 @@ func NewInMemoryChannel(config *TelemetryConfiguration) *InMemoryChannel {
 		batchSize:       config.MaxBatchSize,
 		batchInterval:   config.MaxBatchInterval,
 		throttle:        newThrottleManager(),
-		transmitter:     newTransmitter(config.EndpointUrl),
+		transmitter:     newTransmitter(config.EndpointUrl, config.Client),
 	}
 
 	go channel.acceptLoop()

appinsights/transmitter.go

@@ -16,6 +16,7 @@ type transmitter interface {
 
 type httpTransmitter struct {
 	endpoint string
+	client   *http.Client
 }
 
 type transmissionResult struct {
@@ -50,8 +51,11 @@ const (
 	serviceUnavailableResponse              = 503
 )
 
-func newTransmitter(endpointAddress string) transmitter {
+func newTransmitter(endpointAddress string, client *http.Client) transmitter {
-	return &httpTransmitter{endpointAddress}
+	if client == nil {
+		client = http.DefaultClient
+	}
+	return &httpTransmitter{endpointAddress, client}
 }
 
 func (transmitter *httpTransmitter) Transmit(payload []byte, items telemetryBufferItems) (*transmissionResult, error) {
@@ -78,8 +82,7 @@ func (transmitter *httpTransmitter) Transmit(payload []byte, items telemetryBuff
 	req.Header.Set("Content-Type", "application/x-json-stream")
 	req.Header.Set("Accept-Encoding", "gzip, deflate")
 
-	client := http.DefaultClient
+	resp, err := transmitter.client.Do(req)
-	resp, err := client.Do(req)
 	if err != nil {
 		diagnosticsWriter.Printf("Failed to transmit telemetry: %s", err.Error())
 		return nil, err

appinsights/transmitter_test.go

@@ -74,7 +74,7 @@ func newTestClientServer() (transmitter, *testServer) {
 	server.responseData = make([]byte, 0)
 	server.responseHeaders = make(map[string]string)
 
-	client := newTransmitter(fmt.Sprintf("http://%s/v2/track", server.server.Listener.Addr().String()))
+	client := newTransmitter(fmt.Sprintf("http://%s/v2/track", server.server.Listener.Addr().String()), nil)
 
 	return client, server
 }