1) added custom optional custom http port

2) filling README.md started

README.md

@@ -1,2 +1,23 @@
 Golang sizeof tips
 ------------------
+
+**Web tool for interactive playing with Golang struct sizes.**
+
+## Install
+To install correct versions of dependencies
+[Goop dependency manager](https://github.com/nitrous-io/goop) should be used.
+```bash
+go get github.com/gophergala/golang-sizeof.tips
+cd github.com/gophergala/golang-sizeof.tips
+goop install
+goop go build -o ./server
+```
+You may also install via simple `go get` by your own risk.
+
+
+## Starting, stoping, restarting
+```bash
+./server -http=:7777 start
+./server stop
+./server restart
+```

app/app.go

@@ -4,7 +4,7 @@ import "github.com/gophergala/golang-sizeof.tips/internal/log"
 
 var appLog log.Logger
 
-var HttpPort = ":7777"
+const DefaultHttpPort = ":7777"
 
 // Represents simple zero-cost message that can be used
 // as signal between goroutines.

app/daemon.go

@@ -1,6 +1,7 @@
 package app
 
 import (
+	"flag"
 	"fmt"
 	"io/ioutil"
 	"os"
@@ -16,6 +17,11 @@ func init() {
 	daemon.AppName = "golang-sizeof.tips HTTP server"
 	daemon.PidFile = "logs/sizeof.pid"
 
+	httpPort := ""
+	flag.StringVar(
+		&httpPort, "http", DefaultHttpPort, "port to listen http reauests on",
+	)
+
 	// Overwriting default daemonigo "start" action.
 	daemon.SetAction("start", func() {
 		switch isRunning, _, err := daemon.Status(); {
@@ -26,7 +32,7 @@ func init() {
 				"%s is already started and running now\n", daemon.AppName,
 			)
 		default:
-			daemonStart()
+			daemonStart(httpPort)
 		}
 	})
 
@@ -46,12 +52,12 @@ func init() {
 				fmt.Println("OK")
 			}
 		}
-		daemonStart()
+		daemonStart(httpPort)
 	})
 }
 
 // Helper function for custom daemon starting.
-func daemonStart() {
+func daemonStart(port string) {
 	fmt.Printf("Starting %s...", daemon.AppName)
 	sig := make(chan os.Signal)
 	signal.Notify(sig, syscall.SIGUSR1)
@@ -60,6 +66,9 @@ func daemonStart() {
 		printFailed(err)
 		return
 	}
+	if port != "" {
+		cmd.Env = append(cmd.Env, "_GO_HTTP="+port)
+	}
 	stdErr, err := cmd.StderrPipe()
 	if err != nil {
 		printFailed(err)

app/run.go

@@ -38,14 +38,19 @@ func Run() (exitCode int) {
 		return 1
 	}
 
+	httpPort := os.Getenv("_GO_HTTP")
+	if httpPort == "" {
+		httpPort = DefaultHttpPort
+	}
+
 	bindHttpHandlers()
 	canExit, httpErr := make(chan sig, 1), make(chan error, 1)
 	go func() {
 		defer close(canExit)
-		if err := http.ListenAndServe(HttpPort, nil); err != nil {
+		if err := http.ListenAndServe(httpPort, nil); err != nil {
 			httpErr <- fmt.Errorf(
 				"creating HTTP server on port '%s' FAILED, reason -> %s",
-				HttpPort, err.Error(),
+				httpPort, err.Error(),
 			)
 		}
 	}()