create tapper modes for debugging using env vars

agent/main.go

@@ -292,9 +292,12 @@ func pipeTapChannelToSocket(connection *websocket.Conn, messageDataChannel <-cha
 			continue
 		}
 
+		if os.Getenv("MIZU_TAPPER_NO_SENDING") == "true" {
+			continue
+		}
+
 		// NOTE: This is where the `*tapApi.OutputChannelItem` leaves the code
 		// and goes into the intermediate WebSocket.
-		// (DEBUG_PERF 7) Comment out to disable writing to WebSocket
 		err = connection.WriteMessage(websocket.TextMessage, marshaledData)
 		if err != nil {
 			logger.Log.Errorf("error sending message through socket server %v, err: %s, (%v,%+v)", messageData, err, err, err)

tap/api/api.go

@@ -149,7 +149,10 @@ type Emitter interface {
 }
 
 func (e *Emitting) Emit(item *OutputChannelItem) {
-	// (DEBUG_PERF 6) Comment out to disable emitting from tapper to api-server
+	if os.Getenv("MIZU_TAPPER_NO_EMITTER") == "true" {
+		return
+	}
+	
 	e.OutputChannel <- item
 	e.AppStats.IncMatchedPairs()
 }

tap/source/packet_source_manager.go

@@ -44,7 +44,6 @@ func NewPacketSourceManager(procfs string, filename string, interfaceName string
 		behaviour:     behaviour,
 	}
 
-	// (DEBUG_PERF 1) Comment out to disable host pcap (do not pass --tls or --service-mesh)
 	go hostSource.readPackets(ipdefrag, packets)
 	return sourceManager, nil
 }

tap/source/tcp_packet_source.go

@@ -1,6 +1,7 @@
 package source
 
 import (
+	"os"
 	"fmt"
 	"io"
 	"time"
@@ -116,6 +117,10 @@ func (source *tcpPacketSource) close() {
 }
 
 func (source *tcpPacketSource) readPackets(ipdefrag bool, packets chan<- TcpPacketInfo) {
+	if os.Getenv("MIZU_TAPPER_NO_PCAP") == "true" {
+		return
+	}
+	
 	logger.Log.Infof("Start reading packets from %v", source.name)
 
 	for {

tap/tcp_assembler.go

@@ -78,7 +78,6 @@ func (a *tcpAssembler) processPackets(dumpPacket bool, packets <-chan source.Tcp
 			logger.Log.Debugf("Packet content (%d/0x%x) - %s", len(data), len(data), hex.Dump(data))
 		}
 
-		// (DEBUG_PERF 2) Comment out to disable assembler
 		tcp := packet.Layer(layers.LayerTypeTCP)
 		if tcp != nil {
 			diagnose.AppStats.IncTcpPacketsCount()
@@ -90,7 +89,9 @@ func (a *tcpAssembler) processPackets(dumpPacket bool, packets <-chan source.Tcp
 			}
 			diagnose.InternalStats.Totalsz += len(tcp.Payload)
 			a.assemblerMutex.Lock()
-			a.AssembleWithContext(packet.NetworkLayer().NetworkFlow(), tcp, &c)
+			if os.Getenv("MIZU_TAPPER_NO_ASSEMBLER") != "true" {
+				a.AssembleWithContext(packet.NetworkLayer().NetworkFlow(), tcp, &c)
+			}
 			a.assemblerMutex.Unlock()
 		}
 

tap/tcp_reader.go

@@ -1,6 +1,7 @@
 package tap
 
 import (
+	"os"
 	"bufio"
 	"io"
 	"io/ioutil"
@@ -55,8 +56,12 @@ func NewTcpReader(msgQueue chan api.TcpReaderDataMsg, progress *api.ReadProgress
 func (reader *tcpReader) run(options *api.TrafficFilteringOptions, wg *sync.WaitGroup) {
 	defer wg.Done()
 	b := bufio.NewReader(reader)
-	// (DEBUG_PERF 4) Swap with next line to disable dissectors
-	// _, _ = io.ReadAll(b)
+	
+	if os.Getenv("MIZU_TAPPER_NO_DISSECTORS") == "true" {
+		io.ReadAll(b)
+		return
+	}
+	
 	err := reader.extension.Dissector.Dissect(b, reader, options)
 	if err != nil {
 		_, err = io.Copy(ioutil.Discard, reader)

tap/tcp_stream.go

@@ -1,6 +1,7 @@
 package tap
 
 import (
+	"os"
 	"sync"
 	"time"
 
@@ -132,7 +133,10 @@ func (t *tcpStream) GetReqResMatchers() []api.RequestResponseMatcher {
 }
 
 func (t *tcpStream) GetIsTapTarget() bool {
-	// (DEBUG_PERF 3) Return false to disable Dissecting
+	if os.Getenv("MIZU_TAPPER_NO_TAP_TARGET") == "true" {
+		return false
+	}
+	
 	return t.isTapTarget
 }