Make listen echo optional

README.md

@@ -116,7 +116,7 @@ and/or environment variables.
 All available flags can be seen by running `cyn --help`. This README snippet should
 have the latest, but when in doubt, just run the command to check.
 
-```bash
+```text
 $ cyn --help
 Usage:
    [flags]
@@ -130,6 +130,7 @@ Flags:
   -c, --config string            A file path to load as additional configuration.
   -h, --help                     help for this command
       --http.address string      An address:port to host an HTTP server on for realtime data, such as '127.0.0.1:8080'
+  -e, --listen.echo              If enabled, echo the data that's received. Otherwise just print the length received (default).
   -t, --listen.tcp strings       An IP:port address to listen on for TCP.  Can be specified multiple times.
   -u, --listen.udp strings       An IP:port address to listen on for UDP.  Can be specified multiple times.
   -d, --send.data string         The string data to send. (default "hi")
@@ -161,6 +162,7 @@ A full configuration file with all options is given below.
 ```yaml
 # my-cyn-config.yaml
 listen:
+  echo: true
   udp:
     - 192.168.58.4:2345
   tcp:

cmd/cyn/cmds/root.go

@@ -18,8 +18,9 @@ import (
 
 var config struct {
 	Listen struct {
-		Udp []string `mapstructure:"udp"`
-		Tcp []string `mapstructure:"tcp"`
+		Udp  []string `mapstructure:"udp"`
+		Tcp  []string `mapstructure:"tcp"`
+		Echo bool     `mapstructure:"echo"`
 	} `mapstructure:"listen"`
 
 	Send struct {
@@ -55,6 +56,7 @@ func init() {
 
 	flags.StringSliceP("listen.udp", "u", nil, "An IP:port address to listen on for UDP.  Can be specified multiple times.")
 	flags.StringSliceP("listen.tcp", "t", nil, "An IP:port address to listen on for TCP.  Can be specified multiple times.")
+	flags.BoolP("listen.echo", "e", false, "If enabled, echo the data that's received. Otherwise just print the length received (default).")
 	flags.StringSliceP("send.udp", "U", nil, "An IP:port address to send to (UDP).  Can be specified multiple times.")
 	flags.StringSliceP("send.tcp", "T", nil, "An IP:port address to send to (TCP).  Can be specified multiple times.")
 	flags.StringP("send.data", "d", "hi", "The string data to send.")
@@ -113,7 +115,9 @@ var rootCmd = &cobra.Command{
 				return fmt.Errorf("net.ResolveUDPAddr for %q: %w", listenOnUDP, err)
 			}
 
-			instance.AddUDPListener(listener.NewUDP(*addr))
+			instance.AddUDPListener(listener.NewUDP(*addr, listener.UdpConfig{
+				Echo: config.Listen.Echo,
+			}))
 		}
 
 		for _, listenOnTCP := range config.Listen.Tcp {
@@ -123,7 +127,9 @@ var rootCmd = &cobra.Command{
 				return fmt.Errorf("net.ResolveTCPAddr for %q: %w", listenOnTCP, err)
 			}
 
-			instance.AddTCPListener(listener.NewTCP(*addr))
+			instance.AddTCPListener(listener.NewTCP(*addr, listener.TcpConfig{
+				Echo: config.Listen.Echo,
+			}))
 		}
 
 		for _, sendUDPTo := range config.Send.Udp {

pkg/cyn/cyn.go

@@ -11,8 +11,8 @@ import (
 type Cyn struct {
 	mu sync.RWMutex
 
-	tcpListeners []*listener.TCPListener
-	udpListeners []*listener.UDPListener
+	tcpListeners []*listener.TcpListener
+	udpListeners []*listener.UdpListener
 	tcpSenders   []*sender.TCPSender
 	udpSenders   []*sender.UDPSender
 
@@ -23,33 +23,33 @@ func New() *Cyn {
 	return &Cyn{}
 }
 
-func (c *Cyn) AddTCPListener(tcpListener *listener.TCPListener) {
+func (c *Cyn) AddTCPListener(tcpListener *listener.TcpListener) {
 	c.mu.Lock()
 	c.tcpListeners = append(c.tcpListeners, tcpListener)
 	c.mu.Unlock()
 }
 
-func (c *Cyn) TCPListeners() []*listener.TCPListener {
+func (c *Cyn) TCPListeners() []*listener.TcpListener {
 	c.mu.RLock()
 	defer c.mu.RUnlock()
 
-	listeners := make([]*listener.TCPListener, len(c.tcpListeners))
+	listeners := make([]*listener.TcpListener, len(c.tcpListeners))
 	copy(listeners, c.tcpListeners)
 
 	return listeners
 }
 
-func (c *Cyn) AddUDPListener(udpListener *listener.UDPListener) {
+func (c *Cyn) AddUDPListener(udpListener *listener.UdpListener) {
 	c.mu.Lock()
 	c.udpListeners = append(c.udpListeners, udpListener)
 	c.mu.Unlock()
 }
 
-func (c *Cyn) UDPListeners() []*listener.UDPListener {
+func (c *Cyn) UDPListeners() []*listener.UdpListener {
 	c.mu.RLock()
 	defer c.mu.RUnlock()
 
-	listeners := make([]*listener.UDPListener, len(c.udpListeners))
+	listeners := make([]*listener.UdpListener, len(c.udpListeners))
 	copy(listeners, c.udpListeners)
 
 	return listeners

pkg/httpserver/server.go

@@ -13,8 +13,8 @@ type Server struct {
 }
 
 type OverallStatusGetter interface {
-	TCPListeners() []*listener.TCPListener
-	UDPListeners() []*listener.UDPListener
+	TCPListeners() []*listener.TcpListener
+	UDPListeners() []*listener.UdpListener
 }
 
 func NewServer(addr string, statusGetter OverallStatusGetter) *Server {

pkg/listener/tcp.go

@@ -11,25 +11,31 @@ import (
 	"github.com/evertras/cynomys/pkg/constants"
 )
 
-type TCPListener struct {
+type TcpListener struct {
 	mu   sync.RWMutex
 	addr net.TCPAddr
+	cfg  TcpConfig
 }
 
-func NewTCP(addr net.TCPAddr) *TCPListener {
-	return &TCPListener{
+type TcpConfig struct {
+	Echo bool
+}
+
+func NewTCP(addr net.TCPAddr, cfg TcpConfig) *TcpListener {
+	return &TcpListener{
 		addr: addr,
+		cfg:  cfg,
 	}
 }
 
-func (l *TCPListener) Addr() string {
+func (l *TcpListener) Addr() string {
 	l.mu.RLock()
 	defer l.mu.RUnlock()
 
 	return l.addr.String()
 }
 
-func (l *TCPListener) Listen() error {
+func (l *TcpListener) Listen() error {
 	l.mu.RLock()
 	listener, err := net.ListenTCP("tcp", &l.addr)
 	l.mu.RUnlock()
@@ -76,7 +82,10 @@ func (l *TCPListener) Listen() error {
 				}
 
 				log.Printf("Read %d bytes from %v", rlen, remote)
-				log.Printf("Received: %s", strings.ReplaceAll(string(buf), "\n", "\\n"))
+
+				if l.cfg.Echo {
+					log.Printf("Received: %s", strings.ReplaceAll(string(buf), "\n", "\\n"))
+				}
 			}
 
 			log.Printf("TCP disconnected from %s", remote)

pkg/listener/udp.go

@@ -10,25 +10,31 @@ import (
 	"github.com/evertras/cynomys/pkg/constants"
 )
 
-type UDPListener struct {
+type UdpListener struct {
 	mu   sync.RWMutex
 	addr net.UDPAddr
+	cfg  UdpConfig
 }
 
-func NewUDP(addr net.UDPAddr) *UDPListener {
-	return &UDPListener{
+type UdpConfig struct {
+	Echo bool
+}
+
+func NewUDP(addr net.UDPAddr, cfg UdpConfig) *UdpListener {
+	return &UdpListener{
 		addr: addr,
+		cfg:  cfg,
 	}
 }
 
-func (l *UDPListener) Addr() string {
+func (l *UdpListener) Addr() string {
 	l.mu.RLock()
 	defer l.mu.RUnlock()
 
 	return l.addr.String()
 }
 
-func (l *UDPListener) Listen() error {
+func (l *UdpListener) Listen() error {
 	l.mu.RLock()
 	conn, err := net.ListenUDP("udp", &l.addr)
 	l.mu.RUnlock()
@@ -55,6 +61,9 @@ func (l *UDPListener) Listen() error {
 		}
 
 		log.Printf("Read %d bytes from %v", rlen, remote)
-		log.Printf("Received: %s", strings.ReplaceAll(string(buf), "\n", "\\n"))
+
+		if l.cfg.Echo {
+			log.Printf("Received: %s", strings.ReplaceAll(string(buf), "\n", "\\n"))
+		}
 	}
 }

tests/features/listen-tcp.feature

@@ -23,7 +23,7 @@ Feature: listen for TCP
     And the stdout contains "TCP disconnected"
 
   Scenario: a TCP connection is made and data is sent (shorthand flag)
-    Given I run cyn -t 127.0.0.1:24565
+    Given I run cyn -t 127.0.0.1:24565 -e
     When I connect with TCP to 127.0.0.1:24565
     And I send "my tcp stuff" over my TCP connection
     And I wait a moment
@@ -34,6 +34,7 @@ Feature: listen for TCP
     Given a configuration file that contains:
       """
       listen:
+        echo: true
         tcp:
           - 127.0.0.1:14568
       """

tests/features/listen-udp.feature

@@ -4,17 +4,22 @@ Feature: listen for UDP
 
   Scenario: nothing is sent
     #Given cyn is listening for UDP on 127.0.0.1:14563
-    Given I run cyn --listen.udp 127.0.0.1:14563
+    Given I run cyn --listen.udp 127.0.0.1:14563 -e
     When I wait 1 second
     Then there is no output
 
   Scenario: a single UDP packet is sent
-    Given I run cyn --listen.udp 127.0.0.1:14564
+    Given I run cyn --listen.udp 127.0.0.1:14564 --listen.echo
     When I send a UDP packet containing "hello" to 127.0.0.1:14564
     Then the stdout contains "hello"
 
+  Scenario: a single UDP packet is sent but listen.echoecho is not defined
+    Given I run cyn --listen.udp 127.0.0.1:14564
+    When I send a UDP packet containing "hello" to 127.0.0.1:14564
+    Then the stdout does not contain "hello"
+
   Scenario: multiple UDP packets are sent (shorthand flag)
-    Given I run cyn -u 127.0.0.1:14564
+    Given I run cyn -u 127.0.0.1:14564 -e
     When I send a UDP packet containing "hello" to 127.0.0.1:14564
     And I send a UDP packet containing "another" to 127.0.0.1:14564
     Then the stdout contains "hello"
@@ -24,6 +29,7 @@ Feature: listen for UDP
     Given a configuration file that contains:
       """
       listen:
+        echo: true
         udp:
           - 127.0.0.1:14568
       """

tests/features/tcp.feature

@@ -8,7 +8,7 @@ Feature: send and receive TCP
     Then the stdout contains "connection refused"
 
   Scenario: one listen one send (shorthand flags)
-    Given I run cyn -t 127.0.0.1:15235
+    Given I run cyn -t 127.0.0.1:15235 -e
     And I run cyn -T 127.0.0.1:15235 -i 10ms
     When I wait a moment
     Then the stdout contains "connected"
@@ -38,6 +38,7 @@ Feature: send and receive TCP
     Given a configuration file that contains:
       """
       listen:
+        echo: true
         tcp:
           - 127.0.0.1:24568
       send:
@@ -53,6 +54,7 @@ Feature: send and receive TCP
     Given a configuration file that contains:
       """
       listen:
+        echo: true
         tcp:
           - 127.0.0.1:24568
       send:

tests/features/udp.feature

@@ -3,13 +3,13 @@ Feature: send and receive UDP
   Cyn should both send and receive UDP packets
 
   Scenario: one listen one send to nothing
-    Given I run cyn --listen-udp 127.0.0.1:14563
+    Given I run cyn --listen-udp 127.0.0.1:14563 --listen.echo
     And I run cyn --send.udp 127.0.0.1:14568 --send.interval 10ms
     When I wait a moment
     Then the stdout contains "connection refused"
 
   Scenario: one listen one send (shorthand flags)
-    Given I run cyn -u 127.0.0.1:14563
+    Given I run cyn -u 127.0.0.1:14563 -e
     And I run cyn -U 127.0.0.1:14563 -i 10ms -d "bdd-test-data"
     When I wait a moment
     Then the stdout contains "bdd-test-data"
@@ -26,6 +26,7 @@ Feature: send and receive UDP
       listen:
         udp:
           - 127.0.0.1:14568
+        echo: true
       send:
         udp:
           - 127.0.0.1:14568