Implements bootstrap, fixes #3

bootstrap.go

@@ -0,0 +1,76 @@
+// Copyright 2018 Mikhail Klementev. All rights reserved.
+// Use of this source code is governed by a AGPLv3 license
+// (or later) that can be found in the LICENSE file.
+
+package main
+
+import (
+	"io"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"os"
+	"os/exec"
+	"os/user"
+)
+
+// inspired by Edd Turtle code
+func downloadFile(filepath string, url string) (err error) {
+	out, err := os.Create(filepath)
+	if err != nil {
+		return
+	}
+	defer out.Close()
+
+	resp, err := http.Get(url)
+	if err != nil {
+		return
+	}
+	defer resp.Body.Close()
+
+	_, err = io.Copy(out, resp.Body)
+	return
+}
+
+func unpackTar(archive, destination string) (err error) {
+	cmd := exec.Command("tar", "xf", archive)
+	cmd.Dir = destination + "/"
+
+	rawOutput, err := cmd.CombinedOutput()
+	if err != nil {
+		// I don't like when some errors printed inside
+		// So if you know way to do it better - FIXME please
+		log.Println("Unpack images error:", string(rawOutput), err)
+		return
+	}
+
+	return
+}
+
+func bootstrapHandler() (err error) {
+	usr, err := user.Current()
+	if err != nil {
+		return
+	}
+
+	imagesPath := usr.HomeDir + "/.out-of-tree/images/"
+	os.MkdirAll(imagesPath, os.ModePerm)
+
+	tmp, err := ioutil.TempDir("/tmp/", "out-of-tree_")
+	if err != nil {
+		log.Println("Temporary directory creation error:", err)
+		return
+	}
+	defer os.RemoveAll(tmp)
+
+	imagesArchive := tmp + "/images.tar.gz"
+
+	err = downloadFile(imagesArchive, imagesURL)
+	if err != nil {
+		log.Println("Download file error:", err)
+		return
+	}
+
+	err = unpackTar(imagesArchive, imagesPath)
+	return
+}