Do not set http header if it explicitly set

Makefile

@@ -20,7 +20,7 @@ drace:
 	docker run -v `pwd`:$(SOURCE_PATH) -t -i --env GORACE="halt_on_error=1" gor go test ./... $(ARGS) -v -race -timeout 15s
 
 dtest:
-	docker run -v `pwd`:$(SOURCE_PATH) -t -i gor go test ./... $(ARGS) -v -timeout 5s
+	docker run -v `pwd`:$(SOURCE_PATH) -t -i gor go test ./... $(ARGS) -v -timeout 10s
 
 dcover:
 	docker run -v `pwd`:$(SOURCE_PATH) -t -i --env GORACE="halt_on_error=1" gor go test $(ARGS) -race -v -timeout 15s -coverprofile=coverage.out

http_client.go

@@ -20,6 +20,7 @@ var defaultPorts = map[string]string{
 type HTTPClientConfig struct {
 	FollowRedirects int
 	Debug           bool
+	OriginalHost    bool
 }
 
 type HTTPClient struct {
@@ -115,7 +116,9 @@ func (c *HTTPClient) Send(data []byte) (response []byte, err error) {
 
 	c.conn.SetWriteDeadline(timeout)
 
-	data = proto.SetHost(data, []byte(c.baseURL), []byte(c.host))
+	if !c.config.OriginalHost {
+		data = proto.SetHost(data, []byte(c.baseURL), []byte(c.host))
+	}
 
 	if c.config.Debug {
 		Debug("[HTTPClient] Sending:", string(data))

output_file.go

@@ -21,7 +21,6 @@ type FileOutput struct {
 	file    *os.File
 }
 
-
 // NewFileOutput constructor for FileOutput, accepts path
 func NewFileOutput(path string) io.Writer {
 	o := new(FileOutput)

output_http.go

@@ -18,6 +18,8 @@ type HTTPOutputConfig struct {
 
 	elasticSearch string
 
+	OriginalHost bool
+
 	Debug bool
 }
 
@@ -94,6 +96,7 @@ func (o *HTTPOutput) startWorker() {
 	client := NewHTTPClient(o.address, &HTTPClientConfig{
 		FollowRedirects: o.config.redirectLimit,
 		Debug:           o.config.Debug,
+		OriginalHost:    o.config.OriginalHost,
 	})
 
 	deathCount := 0

output_http_test.go

@@ -76,6 +76,40 @@ func TestHTTPOutput(t *testing.T) {
 	Settings.modifierConfig = HTTPModifierConfig{}
 }
 
+func TestHTTPOutputKeepOriginalHost(t *testing.T) {
+	wg := new(sync.WaitGroup)
+	quit := make(chan int)
+
+	input := NewTestInput()
+
+	listener := startHTTP(func(req *http.Request) {
+		if req.Host != "custom-host.com" {
+			t.Error("Wrong header", req.Host)
+		}
+
+		wg.Done()
+	})
+
+	headers := HTTPHeaders{HTTPHeader{"Host", "custom-host.com"}}
+	Settings.modifierConfig = HTTPModifierConfig{headers: headers}
+
+	output := NewHTTPOutput(listener.Addr().String(), &HTTPOutputConfig{Debug: false, OriginalHost: true})
+
+	Plugins.Inputs = []io.Reader{input}
+	Plugins.Outputs = []io.Writer{output}
+
+	go Start(quit)
+
+	wg.Add(1)
+	input.EmitGET()
+
+	wg.Wait()
+
+	close(quit)
+
+	Settings.modifierConfig = HTTPModifierConfig{}
+}
+
 func TestOutputHTTPSSL(t *testing.T) {
 	wg := new(sync.WaitGroup)
 	quit := make(chan int)

plugins.go

@@ -98,6 +98,15 @@ func InitPlugins() {
 		registerPlugin(NewHTTPInput, options)
 	}
 
+	// If we explicitly set Host header http output should not rewrite it
+	// Fix: https://github.com/buger/gor/issues/174
+	for _, header := range Settings.modifierConfig.headers {
+		if header.Name == "Host" {
+			Settings.outputHTTPConfig.OriginalHost = true
+			break
+		}
+	}
+
 	for _, options := range Settings.outputHTTP {
 		registerPlugin(NewHTTPOutput, options, &Settings.outputHTTPConfig)
 	}

raw_socket_listener/listener.go

@@ -27,12 +27,12 @@ type Listener struct {
 
 	// Expect: 100-continue request is send in 2 tcp messages
 	// We store ACK aliases to merge this packets together
-	ackAliases   map[uint32]uint32
+	ackAliases map[uint32]uint32
 	// To get ACK of second message we need to compute its Seq and wait for them message
 	seqWithData map[uint32]uint32
 
 	// Messages ready to be send to client
-	packetsChan  chan *TCPPacket
+	packetsChan chan *TCPPacket
 
 	// Messages ready to be send to client
 	messagesChan chan *TCPMessage