webgui: Move to new package fs/rc/webgui.

fs/rc/webgui/webgui.go

@@ -0,0 +1,241 @@
+// Define the Web GUI helpers
+
+package webgui
+
+import (
+	"archive/zip"
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/rclone/rclone/fs"
+	"github.com/rclone/rclone/lib/errors"
+)
+
+// getLatestReleaseURL returns the latest release details of the rclone-webui-react
+func getLatestReleaseURL(fetchURL string) (string, string, int, error) {
+	resp, err := http.Get(fetchURL)
+	if err != nil {
+		return "", "", 0, errors.New("Error getting latest release of rclone-webui")
+	}
+	results := gitHubRequest{}
+	if err := json.NewDecoder(resp.Body).Decode(&results); err != nil {
+		return "", "", 0, errors.New("Could not decode results from http request")
+	}
+
+	res := results.Assets[0].BrowserDownloadURL
+	tag := results.TagName
+	size := results.Assets[0].Size
+
+	return res, tag, size, nil
+}
+
+// CheckAndDownloadWebGUIRelease is a helper function to download and setup latest release of rclone-webui-react
+func CheckAndDownloadWebGUIRelease(checkUpdate bool, forceUpdate bool, fetchURL string, cacheDir string) (err error) {
+	cachePath := filepath.Join(cacheDir, "webgui")
+	tagPath := filepath.Join(cachePath, "tag")
+	extractPath := filepath.Join(cachePath, "current")
+
+	extractPathExist, extractPathStat, err := exists(extractPath)
+	if err != nil {
+		return err
+	}
+
+	if extractPathExist && !extractPathStat.IsDir() {
+		return errors.New("Web GUI path exists, but is a file instead of folder. Please check the path " + extractPath)
+	}
+
+	// if the old file exists does not exist or forced update is enforced.
+	// TODO: Add hashing to check integrity of the previous update.
+	if !extractPathExist || checkUpdate || forceUpdate {
+		// Get the latest release details
+		WebUIURL, tag, size, err := getLatestReleaseURL(fetchURL)
+		if err != nil {
+			return err
+		}
+
+		dat, err := ioutil.ReadFile(tagPath)
+		if err == nil && string(dat) == tag {
+			fs.Logf(nil, "No update to Web GUI available.")
+			if !forceUpdate {
+				return nil
+			}
+			fs.Logf(nil, "Force update the Web GUI binary.")
+		}
+
+		zipName := tag + ".zip"
+		zipPath := filepath.Join(cachePath, zipName)
+
+		cachePathExist, cachePathStat, _ := exists(cachePath)
+		if !cachePathExist {
+			if err := os.MkdirAll(cachePath, 0755); err != nil {
+				return errors.New("Error creating cache directory: " + cachePath)
+			}
+		}
+
+		if cachePathExist && !cachePathStat.IsDir() {
+			return errors.New("Web GUI path is a file instead of folder. Please check it " + extractPath)
+		}
+
+		fs.Logf(nil, "A new release for gui is present at "+WebUIURL)
+		fs.Logf(nil, "Downloading webgui binary. Please wait. [Size: %s, Path :  %s]\n", strconv.Itoa(size), zipPath)
+
+		// download the zip from latest url
+		err = downloadFile(zipPath, WebUIURL)
+		if err != nil {
+			return err
+		}
+
+		err = os.RemoveAll(extractPath)
+		if err != nil {
+			fs.Logf(nil, "No previous downloads to remove")
+		}
+		fs.Logf(nil, "Unzipping webgui binary")
+
+		err = unzip(zipPath, extractPath)
+		if err != nil {
+			return err
+		}
+
+		err = os.RemoveAll(zipPath)
+		if err != nil {
+			fs.Logf(nil, "Downloaded ZIP cannot be deleted")
+		}
+
+		err = ioutil.WriteFile(tagPath, []byte(tag), 0644)
+		if err != nil {
+			fs.Infof(nil, "Cannot write tag file. You may be required to redownload the binary next time.")
+		}
+	} else {
+		fs.Logf(nil, "Web GUI exists. Update skipped.")
+	}
+
+	return nil
+}
+
+// downloadFile is a helper function to download a file from url to the filepath
+func downloadFile(filepath string, url string) error {
+
+	// Get the data
+	resp, err := http.Get(url)
+	if err != nil {
+		return err
+	}
+	defer fs.CheckClose(resp.Body, &err)
+
+	// Create the file
+	out, err := os.Create(filepath)
+	if err != nil {
+		return err
+	}
+	defer fs.CheckClose(out, &err)
+
+	// Write the body to file
+	_, err = io.Copy(out, resp.Body)
+	return err
+}
+
+// unzip is a helper function to unzip a file specified in src to path dest
+func unzip(src, dest string) (err error) {
+	dest = filepath.Clean(dest) + string(os.PathSeparator)
+
+	r, err := zip.OpenReader(src)
+	if err != nil {
+		return err
+	}
+	defer fs.CheckClose(r, &err)
+
+	if err := os.MkdirAll(dest, 0755); err != nil {
+		return err
+	}
+
+	// Closure to address file descriptors issue with all the deferred .Close() methods
+	extractAndWriteFile := func(f *zip.File) error {
+		path := filepath.Join(dest, f.Name)
+		// Check for Zip Slip: https://github.com/rclone/rclone/issues/3529
+		if !strings.HasPrefix(path, dest) {
+			return fmt.Errorf("%s: illegal file path", path)
+		}
+
+		rc, err := f.Open()
+		if err != nil {
+			return err
+		}
+		defer fs.CheckClose(rc, &err)
+
+		if f.FileInfo().IsDir() {
+			if err := os.MkdirAll(path, 0755); err != nil {
+				return err
+			}
+		} else {
+			if err := os.MkdirAll(filepath.Dir(path), 0755); err != nil {
+				return err
+			}
+			f, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)
+			if err != nil {
+				return err
+			}
+			defer fs.CheckClose(f, &err)
+
+			_, err = io.Copy(f, rc)
+			if err != nil {
+				return err
+			}
+		}
+		return nil
+	}
+
+	for _, f := range r.File {
+		err := extractAndWriteFile(f)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func exists(path string) (existence bool, stat os.FileInfo, err error) {
+	stat, err = os.Stat(path)
+	if err == nil {
+		return true, stat, nil
+	}
+	if os.IsNotExist(err) {
+		return false, nil, nil
+	}
+	return false, stat, err
+}
+
+// gitHubRequest Maps the GitHub API request to structure
+type gitHubRequest struct {
+	URL string `json:"url"`
+
+	Prerelease  bool      `json:"prerelease"`
+	CreatedAt   time.Time `json:"created_at"`
+	PublishedAt time.Time `json:"published_at"`
+	TagName     string    `json:"tag_name"`
+	Assets      []struct {
+		URL                string    `json:"url"`
+		ID                 int       `json:"id"`
+		NodeID             string    `json:"node_id"`
+		Name               string    `json:"name"`
+		Label              string    `json:"label"`
+		ContentType        string    `json:"content_type"`
+		State              string    `json:"state"`
+		Size               int       `json:"size"`
+		DownloadCount      int       `json:"download_count"`
+		CreatedAt          time.Time `json:"created_at"`
+		UpdatedAt          time.Time `json:"updated_at"`
+		BrowserDownloadURL string    `json:"browser_download_url"`
+	} `json:"assets"`
+	TarballURL string `json:"tarball_url"`
+	ZipballURL string `json:"zipball_url"`
+	Body       string `json:"body"`
+}