update updater (#1009)

beszel/internal/ghupdate/ghupdate.go

@@ -0,0 +1,401 @@
+// Package ghupdate implements a new command to self update the current
+// executable with the latest GitHub release. This is based on PocketBase's
+// ghupdate package with modifications.
+package ghupdate
+
+import (
+	"archive/tar"
+	"beszel"
+	"compress/gzip"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"log/slog"
+	"net/http"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+
+	"github.com/blang/semver"
+	"github.com/pocketbase/pocketbase/core"
+	"github.com/pocketbase/pocketbase/tools/archive"
+)
+
+// Minimal color functions using ANSI escape codes
+const (
+	colorReset  = "\033[0m"
+	ColorYellow = "\033[33m"
+	colorGreen  = "\033[32m"
+	colorCyan   = "\033[36m"
+	colorGray   = "\033[90m"
+)
+
+func ColorPrint(color, text string) {
+	fmt.Println(color + text + colorReset)
+}
+
+func ColorPrintf(color, format string, args ...interface{}) {
+	fmt.Printf(color+format+colorReset+"\n", args...)
+}
+
+// HttpClient is a base HTTP client interface (usually used for test purposes).
+type HttpClient interface {
+	Do(req *http.Request) (*http.Response, error)
+}
+
+// Config defines the config options of the ghupdate plugin.
+//
+// NB! This plugin is considered experimental and its config options may change in the future.
+type Config struct {
+	// Owner specifies the account owner of the repository (default to "pocketbase").
+	Owner string
+
+	// Repo specifies the name of the repository (default to "pocketbase").
+	Repo string
+
+	// ArchiveExecutable specifies the name of the executable file in the release archive
+	// (default to "pocketbase"; an additional ".exe" check is also performed as a fallback).
+	ArchiveExecutable string
+
+	// Optional context to use when fetching and downloading the latest release.
+	Context context.Context
+
+	// The HTTP client to use when fetching and downloading the latest release.
+	// Defaults to `http.DefaultClient`.
+	HttpClient HttpClient
+
+	// The data directory to use when fetching and downloading the latest release.
+	DataDir string
+}
+
+func Update(config Config) (updated bool, err error) {
+	p := &plugin{
+		currentVersion: beszel.Version,
+		config:         config,
+	}
+
+	return p.update()
+}
+
+type plugin struct {
+	config         Config
+	currentVersion string
+}
+
+func (p *plugin) update() (updated bool, err error) {
+	ColorPrint(ColorYellow, "Fetching release information...")
+
+	if p.config.DataDir == "" {
+		p.config.DataDir = os.TempDir()
+	}
+
+	if p.config.Owner == "" {
+		p.config.Owner = "henrygd"
+	}
+
+	if p.config.Repo == "" {
+		p.config.Repo = "beszel"
+	}
+
+	if p.config.Context == nil {
+		p.config.Context = context.Background()
+	}
+
+	if p.config.HttpClient == nil {
+		p.config.HttpClient = http.DefaultClient
+	}
+
+	var latest *release
+	latest, err = fetchLatestRelease(
+		p.config.Context,
+		p.config.HttpClient,
+		fmt.Sprintf("https://api.github.com/repos/%s/%s/releases/latest", p.config.Owner, p.config.Repo),
+	)
+	// if the first fetch fails, try the beszel.dev API (fallback for China)
+	if err != nil {
+		ColorPrint(ColorYellow, "Failed to fetch release. Trying beszel.dev mirror...")
+		latest, err = fetchLatestRelease(
+			p.config.Context,
+			p.config.HttpClient,
+			fmt.Sprintf("https://gh.beszel.dev/repos/%s/%s/releases/latest?api=true", p.config.Owner, p.config.Repo),
+		)
+	}
+	if err != nil {
+		return false, err
+	}
+
+	currentVersion := semver.MustParse(strings.TrimPrefix(p.currentVersion, "v"))
+	newVersion := semver.MustParse(strings.TrimPrefix(latest.Tag, "v"))
+
+	if newVersion.LTE(currentVersion) {
+		ColorPrintf(colorGreen, "You already have the latest version %s.", p.currentVersion)
+		return false, nil
+	}
+
+	suffix := archiveSuffix(p.config.ArchiveExecutable, runtime.GOOS, runtime.GOARCH)
+	asset, err := latest.findAssetBySuffix(suffix)
+	if err != nil {
+		return false, err
+	}
+
+	releaseDir := filepath.Join(p.config.DataDir, core.LocalTempDirName)
+	defer os.RemoveAll(releaseDir)
+
+	ColorPrintf(ColorYellow, "Downloading %s...", asset.Name)
+
+	// download the release asset
+	assetPath := filepath.Join(releaseDir, asset.Name)
+	if err := downloadFile(p.config.Context, p.config.HttpClient, asset.DownloadUrl, assetPath); err != nil {
+		return false, err
+	}
+
+	ColorPrintf(ColorYellow, "Extracting %s...", asset.Name)
+
+	extractDir := filepath.Join(releaseDir, "extracted_"+asset.Name)
+	defer os.RemoveAll(extractDir)
+
+	// Extract based on file extension
+	if strings.HasSuffix(asset.Name, ".tar.gz") {
+		if err := extractTarGz(assetPath, extractDir); err != nil {
+			return false, err
+		}
+	} else {
+		if err := archive.Extract(assetPath, extractDir); err != nil {
+			return false, err
+		}
+	}
+
+	ColorPrint(ColorYellow, "Replacing the executable...")
+
+	oldExec, err := os.Executable()
+	if err != nil {
+		return false, err
+	}
+	renamedOldExec := oldExec + ".old"
+	defer os.Remove(renamedOldExec)
+
+	newExec := filepath.Join(extractDir, p.config.ArchiveExecutable)
+	if _, err := os.Stat(newExec); err != nil {
+		// try again with an .exe extension
+		newExec = newExec + ".exe"
+		if _, fallbackErr := os.Stat(newExec); fallbackErr != nil {
+			return false, fmt.Errorf("the executable in the extracted path is missing or it is inaccessible: %v, %v", err, fallbackErr)
+		}
+	}
+
+	// rename the current executable
+	if err := os.Rename(oldExec, renamedOldExec); err != nil {
+		return false, fmt.Errorf("failed to rename the current executable: %w", err)
+	}
+
+	tryToRevertExecChanges := func() {
+		if revertErr := os.Rename(renamedOldExec, oldExec); revertErr != nil {
+			slog.Debug(
+				"Failed to revert executable",
+				slog.String("old", renamedOldExec),
+				slog.String("new", oldExec),
+				slog.String("error", revertErr.Error()),
+			)
+		}
+	}
+
+	// replace with the extracted binary
+	if err := os.Rename(newExec, oldExec); err != nil {
+		// If rename fails due to cross-device link, try copying instead
+		if isCrossDeviceError(err) {
+			if err := copyFile(newExec, oldExec); err != nil {
+				tryToRevertExecChanges()
+				return false, fmt.Errorf("failed replacing the executable: %w", err)
+			}
+		} else {
+			tryToRevertExecChanges()
+			return false, fmt.Errorf("failed replacing the executable: %w", err)
+		}
+	}
+
+	ColorPrint(colorGray, "---")
+	ColorPrint(colorGreen, "Update completed successfully! You can start the executable as usual.")
+
+	// print the release notes
+	if latest.Body != "" {
+		fmt.Print("\n")
+		ColorPrintf(colorCyan, "Here is a list with some of the %s changes:", latest.Tag)
+		// remove the update command note to avoid "stuttering"
+		// (@todo consider moving to a config option)
+		releaseNotes := strings.TrimSpace(strings.Replace(latest.Body, "> _To update the prebuilt executable you can run `./"+p.config.ArchiveExecutable+" update`._", "", 1))
+		ColorPrint(colorCyan, releaseNotes)
+		fmt.Print("\n")
+	}
+
+	return true, nil
+}
+
+func fetchLatestRelease(
+	ctx context.Context,
+	client HttpClient,
+	url string,
+) (*release, error) {
+	req, err := http.NewRequestWithContext(ctx, "GET", url, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	res, err := client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer res.Body.Close()
+
+	rawBody, err := io.ReadAll(res.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	// http.Client doesn't treat non 2xx responses as error
+	if res.StatusCode >= 400 {
+		return nil, fmt.Errorf(
+			"(%d) failed to fetch latest releases:\n%s",
+			res.StatusCode,
+			string(rawBody),
+		)
+	}
+
+	result := &release{}
+	if err := json.Unmarshal(rawBody, result); err != nil {
+		return nil, err
+	}
+
+	return result, nil
+}
+
+func downloadFile(
+	ctx context.Context,
+	client HttpClient,
+	url string,
+	destPath string,
+) error {
+	req, err := http.NewRequestWithContext(ctx, "GET", url, nil)
+	if err != nil {
+		return err
+	}
+
+	res, err := client.Do(req)
+	if err != nil {
+		return err
+	}
+	defer res.Body.Close()
+
+	// http.Client doesn't treat non 2xx responses as error
+	if res.StatusCode >= 400 {
+		return fmt.Errorf("(%d) failed to send download file request", res.StatusCode)
+	}
+
+	// ensure that the dest parent dir(s) exist
+	if err := os.MkdirAll(filepath.Dir(destPath), os.ModePerm); err != nil {
+		return err
+	}
+
+	dest, err := os.Create(destPath)
+	if err != nil {
+		return err
+	}
+	defer dest.Close()
+
+	if _, err := io.Copy(dest, res.Body); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// isCrossDeviceError checks if the error is due to a cross-device link
+func isCrossDeviceError(err error) bool {
+	return err != nil && (strings.Contains(err.Error(), "cross-device") ||
+		strings.Contains(err.Error(), "EXDEV"))
+}
+
+// copyFile copies a file from src to dst, preserving permissions
+func copyFile(src, dst string) error {
+	sourceFile, err := os.Open(src)
+	if err != nil {
+		return err
+	}
+	defer sourceFile.Close()
+
+	destFile, err := os.Create(dst)
+	if err != nil {
+		return err
+	}
+	defer destFile.Close()
+
+	// Copy the file contents
+	if _, err := io.Copy(destFile, sourceFile); err != nil {
+		return err
+	}
+
+	// Preserve the original file permissions
+	sourceInfo, err := sourceFile.Stat()
+	if err != nil {
+		return err
+	}
+
+	return destFile.Chmod(sourceInfo.Mode())
+}
+
+func archiveSuffix(binaryName, goos, goarch string) string {
+	if goos == "windows" {
+		return fmt.Sprintf("%s_%s_%s.zip", binaryName, goos, goarch)
+	}
+	return fmt.Sprintf("%s_%s_%s.tar.gz", binaryName, goos, goarch)
+}
+
+func extractTarGz(srcPath, destDir string) error {
+	src, err := os.Open(srcPath)
+	if err != nil {
+		return err
+	}
+	defer src.Close()
+
+	gz, err := gzip.NewReader(src)
+	if err != nil {
+		return err
+	}
+	defer gz.Close()
+
+	tr := tar.NewReader(gz)
+
+	for {
+		header, err := tr.Next()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return err
+		}
+
+		if header.Typeflag == tar.TypeDir {
+			if err := os.MkdirAll(filepath.Join(destDir, header.Name), 0755); err != nil {
+				return err
+			}
+			continue
+		}
+
+		if err := os.MkdirAll(filepath.Dir(filepath.Join(destDir, header.Name)), 0755); err != nil {
+			return err
+		}
+
+		outFile, err := os.Create(filepath.Join(destDir, header.Name))
+		if err != nil {
+			return err
+		}
+		defer outFile.Close()
+
+		if _, err := io.Copy(outFile, tr); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}