feat: update button (download, verify, stage)

internal/infrastructure/update/httpAssetFetcher.go

@@ -0,0 +1,185 @@
+package update
+
+import (
+	domain "RenewCMS/internal/domain/update"
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+)
+
+const (
+	maxBinaryBytes       int64 = 200 << 20
+	maxChecksumsBytes    int64 = 64 << 10
+	maxSignatureBytes    int64 = 1 << 10
+	assetDownloadTimeout       = 10 * time.Minute
+	maxAssetRedirects          = 5
+	assetFilePermission        = 0o644
+	signatureSuffix            = ".sig"
+)
+
+var (
+	errAssetURLRefused  = errors.New("the asset url is not https on the release feed host")
+	errAssetStatus      = errors.New("the asset server answered with an error status")
+	errAssetTooLarge    = errors.New("the asset is larger than its size cap")
+	errTooManyRedirects = errors.New("the asset url redirected too many times")
+)
+
+type FileOpener func(path string) (io.WriteCloser, error)
+
+type HTTPAssetFetcher struct {
+	allowedHost   string
+	allowInsecure bool
+	sizeCap       int64
+	timeout       time.Duration
+	transport     http.RoundTripper
+	openFile      FileOpener
+}
+
+var _ domain.AssetFetcher = &HTTPAssetFetcher{}
+
+type FetcherOption func(*HTTPAssetFetcher)
+
+func WithInsecureScheme() FetcherOption {
+	return func(f *HTTPAssetFetcher) { f.allowInsecure = true }
+}
+
+func WithSizeCap(bytes int64) FetcherOption {
+	return func(f *HTTPAssetFetcher) { f.sizeCap = bytes }
+}
+
+func WithTimeout(timeout time.Duration) FetcherOption {
+	return func(f *HTTPAssetFetcher) { f.timeout = timeout }
+}
+
+func WithTransport(transport http.RoundTripper) FetcherOption {
+	return func(f *HTTPAssetFetcher) { f.transport = transport }
+}
+
+func WithFileOpener(opener FileOpener) FetcherOption {
+	return func(f *HTTPAssetFetcher) { f.openFile = opener }
+}
+
+func NewHTTPAssetFetcher(feedURL string, options ...FetcherOption) *HTTPAssetFetcher {
+	fetcher := &HTTPAssetFetcher{
+		allowedHost: domain.HostOf(feedURL),
+		timeout:     assetDownloadTimeout,
+		openFile:    createAssetFile,
+	}
+	for _, option := range options {
+		option(fetcher)
+	}
+	return fetcher
+}
+
+func (f *HTTPAssetFetcher) Fetch(asset domain.Asset, destination string, report domain.ProgressFunc) error {
+	if !f.isAllowed(asset.URL) {
+		return errAssetURLRefused
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), f.timeout)
+	defer cancel()
+	request, err := http.NewRequestWithContext(ctx, http.MethodGet, asset.URL, nil)
+	if err != nil {
+		return err
+	}
+	response, err := f.client().Do(request)
+	if err != nil {
+		return err
+	}
+	defer response.Body.Close()
+	if response.StatusCode != http.StatusOK {
+		return fmt.Errorf("%w: %d", errAssetStatus, response.StatusCode)
+	}
+	limit := f.capFor(asset.Name)
+	if response.ContentLength > limit {
+		return errAssetTooLarge
+	}
+	if err := f.writeBody(response.Body, destination, limit, asset.Size, report); err != nil {
+		_ = os.Remove(destination)
+		return err
+	}
+	return nil
+}
+
+func (f *HTTPAssetFetcher) writeBody(body io.Reader, destination string, limit int64, declaredSize int64, report domain.ProgressFunc) error {
+	file, err := f.openFile(destination)
+	if err != nil {
+		return err
+	}
+	counter := &progressWriter{destination: file, total: declaredSize, report: report}
+	written, copyErr := io.Copy(counter, io.LimitReader(body, limit+1))
+	closeErr := file.Close()
+	if copyErr != nil {
+		return copyErr
+	}
+	if closeErr != nil {
+		return closeErr
+	}
+	if written > limit {
+		return errAssetTooLarge
+	}
+	return nil
+}
+
+func (f *HTTPAssetFetcher) isAllowed(rawURL string) bool {
+	parsed, err := url.Parse(rawURL)
+	if err != nil || f.allowedHost == "" || parsed.Host != f.allowedHost {
+		return false
+	}
+	return parsed.Scheme == "https" || (f.allowInsecure && parsed.Scheme == "http")
+}
+
+func (f *HTTPAssetFetcher) client() *http.Client {
+	return &http.Client{
+		Transport: f.transport,
+		CheckRedirect: func(next *http.Request, via []*http.Request) error {
+			if len(via) >= maxAssetRedirects {
+				return errTooManyRedirects
+			}
+			if !f.isAllowed(next.URL.String()) {
+				return errAssetURLRefused
+			}
+			return nil
+		},
+	}
+}
+
+func (f *HTTPAssetFetcher) capFor(name string) int64 {
+	if f.sizeCap > 0 {
+		return f.sizeCap
+	}
+	if name == domain.ChecksumsAssetName {
+		return maxChecksumsBytes
+	}
+	if strings.HasSuffix(name, signatureSuffix) {
+		return maxSignatureBytes
+	}
+	return maxBinaryBytes
+}
+
+type progressWriter struct {
+	destination io.Writer
+	total       int64
+	done        int64
+	report      domain.ProgressFunc
+}
+
+func (w *progressWriter) Write(chunk []byte) (int, error) {
+	written, err := w.destination.Write(chunk)
+	w.done += int64(written)
+	w.report(w.done, w.total)
+	return written, err
+}
+
+func createAssetFile(path string) (io.WriteCloser, error) {
+	if err := os.MkdirAll(filepath.Dir(path), os.ModePerm); err != nil {
+		return nil, err
+	}
+	return os.OpenFile(path, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, assetFilePermission)
+}