TCP Reset peer toxic documentation.

Update documentation to mention about reset_peer toxic.
Add e2e smoke tests to check format of reset_peer toxic.
Client show the toxic in the help usage output.

Example of usage:

```shell
$ toxiproxy-cli -h http://localhost:8474 create -l localhost:20000 -u localhost:20002 http
$ toxiproxy-cli toxic add --type reset_peer --toxicName "reset_peer" \
                       --attribute "timeout=2000" \
                       --toxicity 1.0 http
$ time curl 127.0.0.1:20000
curl: (56) Recv failure: Connection reset by peer
curl 127.0.0.1:20000  0.00s user 0.00s system 0% cpu 2.010 total
```

CHANGELOG.md

@@ -7,6 +7,8 @@
   /usr/bin/toxiproxy-server
   ```
   (#331, @miry)
+* A new toxic to simulate TCP RESET (Connection reset by peer) on the connections by closing
+  the stub Input immediately or after a timeout. (#247 and #333, @chaosbox)
 
 # [2.1.7]
 

README.md

@@ -55,7 +55,8 @@ stopping you from creating a client in any other language (see
    3. [Bandwidth](#bandwidth)
    4. [Slow close](#slow_close)
    5. [Timeout](#timeout)
-   6. [Slicer](#slicer)
+   6. [Reset peer](#reset_peer)
+   7. [Slicer](#slicer)
 6. [HTTP API](#http-api)
    1. [Proxy fields](#proxy-fields)
    2. [Toxic fields](#toxic-fields)
@@ -404,6 +405,15 @@ Stops all data from getting through, and closes the connection after `timeout`.
 `timeout` is 0, the connection won't close, and data will be delayed until the
 toxic is removed.
 
+Attributes:
+
+ - `timeout`: time in milliseconds
+
+#### reset_peer
+
+Simulate TCP RESET (Connection reset by peer) on the connections by closing the stub Input
+immediately or after a `timeout`.
+
 Attributes:
 
  - `timeout`: time in milliseconds

bin/e2e

@@ -113,6 +113,16 @@ go test -bench=. ./testing -v
 
 echo -e "-----------------\n"
 
+echo "=== Reset peer toxic"
+
+./dist/toxiproxy-cli toxic add --type reset_peer --toxicName "reset_peer" \
+                       --attribute "timeout=2000" \
+                       --toxicity 1.0 shopify_http
+./dist/toxiproxy-cli inspect shopify_http
+./dist/toxiproxy-cli toxic delete --toxicName "reset_peer" shopify_http
+
+echo -e "-----------------\n"
+
 echo "== Teardown"
 
 ./dist/toxiproxy-cli delete shopify_http

cli/cli.go

@@ -44,6 +44,10 @@ var toxicDescription = `
   timeout:    stop all data and close after timeout
               timeout=<ms>
 
+  reset_peer: simulate TCP RESET (Connection reset by peer) on the connections by closing
+              the stub Input immediately or after a timeout
+              timeout=<ms>
+
   slicer:     slice data into bits with optional delay
               average_size=<bytes>,size_variation=<bytes>,delay=<microseconds>
 

link.go

@@ -64,7 +64,6 @@ func NewToxicLink(
 
 // Start the link with the specified toxics.
 func (link *ToxicLink) Start(name string, source io.Reader, dest io.WriteCloser) {
-
 	go func() {
 		bytes, err := io.Copy(link.input, source)
 		if err != nil {
@@ -76,31 +75,33 @@ func (link *ToxicLink) Start(name string, source io.Reader, dest io.WriteCloser)
 		}
 		link.input.Close()
 	}()
+
 	for i, toxic := range link.toxics.chain[link.direction] {
 		if stateful, ok := toxic.Toxic.(toxics.StatefulToxic); ok {
 			link.stubs[i].State = stateful.NewState()
 		}
+
 		if _, ok := toxic.Toxic.(*toxics.ResetToxic); ok {
 			if err := source.(*net.TCPConn).SetLinger(0); err != nil {
 				logrus.WithFields(logrus.Fields{
 					"name":  link.proxy.Name,
 					"toxic": toxic.Type,
 					"err":   err,
-				}).Error("source: Unable to  setLinger(ms)")
-
+				}).Error("source: Unable to setLinger(ms)")
 			}
+
 			if err := dest.(*net.TCPConn).SetLinger(0); err != nil {
 				logrus.WithFields(logrus.Fields{
 					"name":  link.proxy.Name,
 					"toxic": toxic.Type,
 					"err":   err,
-				}).Error("dest: Unable to  setLinger(ms)")
-
+				}).Error("dest: Unable to setLinger(ms)")
 			}
 		}
 
 		go link.stubs[i].Run(toxic)
 	}
+
 	go func() {
 		bytes, err := io.Copy(dest, link.output)
 		if err != nil {

toxics/reset_peer.go

@@ -5,7 +5,8 @@ import (
 )
 
 /*
-The ResetToxic sends closes the connection abruptly after a timeout (in ms). The behaviour of Close is set to discard any unsent/unacknowledged data by setting SetLinger to 0,
+The ResetToxic sends closes the connection abruptly after a timeout (in ms).
+The behavior of Close is set to discard any unsent/unacknowledged data by setting SetLinger to 0,
 ~= sets TCP RST flag and resets the connection.
 If the timeout is set to 0, then the connection will be reset immediately.
 

toxics/reset_peer_test.go

@@ -2,13 +2,14 @@ package toxics_test
 
 import (
 	"bufio"
-	"github.com/Shopify/toxiproxy/toxics"
 	"io"
 	"net"
 	"os"
 	"syscall"
 	"testing"
 	"time"
+
+	"github.com/Shopify/toxiproxy/v2/toxics"
 )
 
 const msg = "reset toxic payload\n"
@@ -21,15 +22,24 @@ func TestResetToxicWithTimeout(t *testing.T) {
 	start := time.Now()
 	resetToxic := toxics.ResetToxic{Timeout: 100}
 	resetTCPHelper(t, ToxicToJson(t, "resettcp", "reset_peer", "upstream", &resetToxic))
-	AssertDeltaTime(t, "Reset after timeout", time.Since(start), time.Duration(resetToxic.Timeout)*time.Millisecond, time.Duration(resetToxic.Timeout+10)*time.Millisecond)
+	AssertDeltaTime(t,
+		"Reset after timeout",
+		time.Since(start),
+		time.Duration(resetToxic.Timeout)*time.Millisecond,
+		time.Duration(resetToxic.Timeout+10)*time.Millisecond,
+	)
 }
 
 func TestResetToxicWithTimeoutDownstream(t *testing.T) {
 	start := time.Now()
 	resetToxic := toxics.ResetToxic{Timeout: 100}
 	resetTCPHelper(t, ToxicToJson(t, "resettcp", "reset_peer", "downstream", &resetToxic))
-	AssertDeltaTime(t, "Reset after timeout", time.Since(start), time.Duration(resetToxic.Timeout)*time.Millisecond, time.Duration(resetToxic.Timeout+10)*time.Millisecond)
-
+	AssertDeltaTime(t,
+		"Reset after timeout",
+		time.Since(start),
+		time.Duration(resetToxic.Timeout)*time.Millisecond,
+		time.Duration(resetToxic.Timeout+10)*time.Millisecond,
+	)
 }
 
 func checkConnectionState(t *testing.T, listenAddress string) {
@@ -49,7 +59,10 @@ func checkConnectionState(t *testing.T, listenAddress string) {
 			t.Error("Expected: connection reset by peer. Got:", err)
 		}
 	} else {
-		t.Error("Expected: connection reset by peer. Got:", err, "conn:", conn.RemoteAddr(), conn.LocalAddr())
+		t.Error(
+			"Expected: connection reset by peer. Got:",
+			err, "conn:", conn.RemoteAddr(), conn.LocalAddr(),
+		)
 	}
 	_, err = conn.Read(tmp)
 	if err != io.EOF {