main.go

package main

import (
	"encoding/json"
	"flag"
	"fmt"
	"io/ioutil"
	"log"
	"net/http"
	"os"
	"path"
	"path/filepath"
	"strings"
)

var directory = flag.String("directory", "/apps", "Root directory to scan")
var port = flag.String("port", "5090", "Port to run webserver on")

func handler(w http.ResponseWriter, r *http.Request) {
	var versions map[string]string = make(map[string]string)

	// allow cross domain AJAX requests
	w.Header().Set("Access-Control-Allow-Origin", "*")

	versionFiles, err := filepath.Glob(path.Join(*directory, "*", "current", "VERSION"))
	if err != nil {
		http.Error(w, err.Error(), 500)
		return
	}

	for _, file := range versionFiles {
		parts := strings.Split(file, string(os.PathSeparator))
		app := parts[len(parts)-3]

		dat, err := ioutil.ReadFile(file)
		if err != nil {
			http.Error(w, err.Error(), 500)
			return
		}

		versions[app] = strings.Trim(string(dat), "\n")
	}

	b, err := json.Marshal(versions)
	if err != nil {
		http.Error(w, err.Error(), 500)
		return
	}
	w.Header().Set("Content-Type", "application/json")
	w.Write(b)
}

func main() {
	flag.Parse()

	http.HandleFunc("/", handler)
	fmt.Printf("Now launching http://0.0.0.0:%s\n", *port)
	err := http.ListenAndServe(":"+*port, nil)
	if err != nil {
		log.Fatal(err)
	}
}