Merge pull request #11 from kffl/feat/lib

feat: enable usage of speedbump as a library/dependency

README.md

@@ -1,20 +1,28 @@
-# speedbump - TCP proxy for simulating variable network latency
+# speedbump - TCP proxy with variable latency
 <div align="center">
-  <img alt="Speedbump Logo" src="https://github.com/kffl/speedbump/raw/HEAD/assets/speedbump.gif" width="480" height="auto"/>
+  <img alt="speedbump logo" src="https://github.com/kffl/speedbump/raw/HEAD/assets/speedbump.gif" width="480" height="auto"/>
 </div>
+Speedbump is a TCP proxy written in Go which allows for simulating variable network latency.
 
-[![CI Workflow](https://github.com/kffl/speedbump/workflows/CI/badge.svg)](https://github.com/kffl/speedbump/actions) [![Go Report Card](https://goreportcard.com/badge/github.com/kffl/speedbump)](https://goreportcard.com/report/github.com/kffl/speedbump) [![Docker Image Version](https://img.shields.io/docker/v/kffl/speedbump)](https://hub.docker.com/r/kffl/speedbump)
+[![CI Workflow](https://github.com/kffl/speedbump/workflows/CI/badge.svg)](https://github.com/kffl/speedbump/actions) [![Go Report Card](https://goreportcard.com/badge/github.com/kffl/speedbump)](https://goreportcard.com/report/github.com/kffl/speedbump) [![Docker Image Version](https://img.shields.io/docker/v/kffl/speedbump)](https://hub.docker.com/r/kffl/speedbump) [![GoDoc](https://godoc.org/github.com/kffl/speedbump/lib?status.svg)](https://godoc.org/github.com/kffl/speedbump/lib)
 
-Speedbump is a TCP proxy which allows for simulating variable network latency.
+## Example usage
 
-## Usage
-
-Spawn a new instance listening on port 2000 that proxies TCP traffic to localhost:80 with a base latency of 100ms and sine wave amplitude of 100ms (resulting in maximum added latency being 200ms and minimum being 0), period of which is 1m:
+Spawn a new instance listening on port 2000 that proxies TCP traffic to localhost:80 with a base latency of 100ms and sine wave amplitude of 100ms (resulting in maximum added latency being 200ms and minimum being 0), period of which is 1 minute:
 
 ```
 speedbump --latency=100ms --sine-amplitude=100ms --sine-period=1m --port=2000 localhost:80
 ```
 
+Spawn a new instance with a base latency of 300ms and a sawtooth wave latency summand with amplitude of 200ms and period of 2 minutes (visualized by the graph below):
+
+```
+speedbump --latency=200ms --saw-amplitude=200ms --saw-period=2m --port=2000 localhost:80
+```
+<div align="center">
+  <img alt="speedbump sawtooth wave graph" src="https://github.com/kffl/speedbump/raw/HEAD/assets/sawtooth.svg" width="800" height="auto"/>
+</div>
+
 ## CLI Arguments Reference:
 
 Output of `speedbump --help`:
@@ -40,6 +48,10 @@ Args:
   <destination>  TCP proxy destination in host:post format.
 ```
 
+## Using speedbump as a library
+
+Speedbump can be used as a Go library via its `lib` package. Check `lib` [README](lib/README.md) for additional information.
+
 ## License
 
 Copyright Paweł Kuffel 2022, licensed under Apache 2.0 License.

args.go

@@ -1,10 +1,11 @@
 package main
 
 import (
+	"github.com/kffl/speedbump/lib"
 	"gopkg.in/alecthomas/kingpin.v2"
 )
 
-func parseArgs(args []string) (*SpeedbumpCfg, error) {
+func parseArgs(args []string) (*lib.SpeedbumpCfg, error) {
 	var app = kingpin.New("speedbump", "TCP proxy for simulating variable network latency.")
 
 	var (
@@ -35,23 +36,23 @@ func parseArgs(args []string) (*SpeedbumpCfg, error) {
 				String()
 	)
 
-	app.Version("0.1.0-rc2")
+	app.Version("0.1.0-rc4")
 	_, err := app.Parse(args)
 
 	if err != nil {
 		return nil, err
 	}
 
-	var cfg = SpeedbumpCfg{
+	var cfg = lib.SpeedbumpCfg{
 		Port:       *port,
 		DestAddr:   *destAddr,
 		BufferSize: int(*bufferSize),
-		Latency: &LatencyCfg{
-			base:          *latency,
-			sineAmplitude: *sineAmplitude,
-			sinePeriod:    *sinePeriod,
-			sawAmplitute:  *sawAmplitute,
-			sawPeriod:     *sawPeriod,
+		Latency: &lib.LatencyCfg{
+			Base:          *latency,
+			SineAmplitude: *sineAmplitude,
+			SinePeriod:    *sinePeriod,
+			SawAmplitute:  *sawAmplitute,
+			SawPeriod:     *sawPeriod,
 		},
 		LogLevel: *logLevel,
 	}

args_test.go

@@ -13,8 +13,8 @@ func TestParseArgsDefault(t *testing.T) {
 	assert.Equal(t, cfg.DestAddr, "localhost:80")
 	assert.Equal(t, cfg.Port, 8000)
 	assert.Equal(t, 0xffff+1, cfg.BufferSize)
-	assert.Equal(t, time.Millisecond*5, cfg.Latency.base)
-	assert.Equal(t, time.Duration(0), cfg.Latency.sineAmplitude)
+	assert.Equal(t, time.Millisecond*5, cfg.Latency.Base)
+	assert.Equal(t, time.Duration(0), cfg.Latency.SineAmplitude)
 }
 
 func TestParseArgsError(t *testing.T) {
@@ -37,9 +37,9 @@ func TestParseArgsAll(t *testing.T) {
 	assert.Equal(t, cfg.DestAddr, "host:777")
 	assert.Equal(t, cfg.Port, 1234)
 	assert.Equal(t, 200, cfg.BufferSize)
-	assert.Equal(t, time.Millisecond*100, cfg.Latency.base)
-	assert.Equal(t, time.Millisecond*50, cfg.Latency.sineAmplitude)
-	assert.Equal(t, time.Minute, cfg.Latency.sinePeriod)
-	assert.Equal(t, time.Duration(0), cfg.Latency.sawAmplitute)
-	assert.Equal(t, time.Duration(0), cfg.Latency.sawPeriod)
+	assert.Equal(t, time.Millisecond*100, cfg.Latency.Base)
+	assert.Equal(t, time.Millisecond*50, cfg.Latency.SineAmplitude)
+	assert.Equal(t, time.Minute, cfg.Latency.SinePeriod)
+	assert.Equal(t, time.Duration(0), cfg.Latency.SawAmplitute)
+	assert.Equal(t, time.Duration(0), cfg.Latency.SawPeriod)
 }